Tennis is a physically and mentally demanding sport that requires proper nutrition and hydration to support training and match-play. The purpose of this article is to provide evidence-based nutritional recommendations for tennis players.
Anthropometric and Physiological Characteristics of Tennis Players
Tennis players do not excel in any particular characteristic but are well adapted in all areas. This is likely a result of the varied nature of tennis match play and training demands.
Energy Expenditures in Tennis
Tennis is broadly considered an intermittent sport, that comprises brief periods of activity interspersed with short active recovery durations and longer passive recovery bouts. The physiological demands of tennis match play are complex and depend on highly variable interactions between technical, tactical, physical, and environmental constraints. Energy expenditures of 440kcal/hr and 646kcal/hr have been reported in women and men players respectively regardless of court surface. Depending on environmental conditions, sweat rates of 0.5 to over 5 L per hour and sodium losses of 0.5 – 1.8 g have been recorded in men and women players.
General Macronutrient and Energy Intake Recommendations for Tennis
Adequate energy must be consumed to support the volume, intensity, and duration of activity. Estimated energy expenditure during tennis play for between 1-5+ h for men can range from 649 kcal to over 3244 kcal. Tennis players should follow a habitually high carbohydrate diet of between 6 to 10 grams per kilogram bodyweight per day to ensure adequate glycogen stores, with women generally requiring slightly less than men. Protein intake guidelines for tennis players training at a high intensity and duration on a daily basis should be around 1.5g per kilogram bodyweight per day and dietary fat intake should not exceed 2 grams per kilogram bodyweight per day.
Carbohydrate Intake Recommendations
It has been understood for many years that a high carbohydrate diet leads to increased muscle glycogen stores, which contributes to optimal performance particularly in endurance-type activities. It is also known that a low carbohydrate diet (<15 % of total energy intake) can impair high-intensity exercise and endurance performance, both of which are key aspects of tennis match-play.
Protein Intake Recommendations
Studies have shown that young tennis players consume over 1.5 grams per kilogram bodyweight per day in protein, which is close to the recommended dietary protein intakes of 1.6 grams per kilogram bodyweight per day. Manipulation of the timing, type, and amount of protein that is consumed, and its co-ingestion with other nutrients will impact the effectiveness of the protein to stimulate protein synthesis and maximize recovery and adaptation.
Fat Intake Recommendations
While carbohydrate is the predominant fuel that is used during tennis, fat oxidation will also contribute to energy provision, especially as the duration of the match or training session increases. With matches lasting anywhere between 2-5 h, endurance is an important element in tennis. It is suggested that the amount of daily fat required to ensure adequate intramuscular triacylglyceride stores for an endurance athlete training for over 2 hrs per day is 2 g/kg. Whatever the dietary requirements of the athlete, some sources of fat must be included in the diet to allow for the absorption of fat-soluble vitamins, synthesis of hormones, and to support effective function of cell membranes.
There is no reason to suspect micronutrient deficiencies in healthy elite-standard tennis players with high energy intakes and varied diets. However, it is important to consume a variety of fruits and vegetables to ensure adequate intake of vitamins and minerals.
Caffeine in doses of 3mg per kg bodyweight provides ergogenic benefit when taken before and/or during tennis match play. Fluid requirements in a range of ambient temperatures are estimated from sweat rate using the regression equation.
200 mL of fluid containing electrolytes should be consumed every change-over in mild to moderate temperatures of less than 27°C but in temperatures greater than 27°C players should aim for over 400 mL.
30-60 grams of carbohydrates per hour should be ingested when match play exceeds 2 hours. Working with a sports dietitian/nutritionist is crucial to optimize and tailor targets for each athlete.
by Manuel Attard M.Sc RD – Sports Dietitian & Nutritionist in Gozo, Malta
Table tennis, often referred to as ping pong, is a fast-paced, high-intensity sport that demands exceptional agility, precision, and stamina. To excel in this sport, athletes must not only hone their skills but also pay close attention to their nutrition. Proper nutrition can enhance performance, aid recovery, and provide the energy needed to compete at the highest level. In this article, we explore the key nutritional strategies for table tennis athletes.
Part 1: Understanding the Table Tennis Athlete’s Needs
Table tennis is an Olympic sport that requires participants to showcase their speed, agility, and mental acuity. It’s a game of quick reactions, lightning-fast rallies, and relentless energy expenditure. To meet these demands, table tennis athletes need a diet plan that caters to their specific requirements.
Carbohydrates: The Energy Source
Carbohydrates are the primary source of energy for athletes, including table tennis players. They provide the fuel needed to sustain intense rallies and maintain focus during matches. Here are the recommended carbohydrate targets:
Daily Intake: Table tennis athletes should aim for approximately 5-10 grams of carbohydrates per kilogram of body weight per day. This range provides the necessary energy for training and competition. Working with a sports dietitian/nutritionist is essential to work out the exact requirements for each athlete.
Pre-Competition: Consume a meal with 1-2 grams of carbohydrates per kilogram of body weight 3-4 hours before a match to ensure energy availability.
Pre-Match Snack: 1-2 hours before a match, opt for low to moderate glycemic index snacks with 1-2 grams of carbohydrates per kilogram of body weight to top up glycogen stores.
During Competition: To maintain energy levels and glycogen stores during multiple matches, sip on carbohydrate-electrolyte drinks or consume carbohydrate gels as needed.
Protein: The Muscle Builder
Protein plays a crucial role in muscle repair and growth. Here are the recommended protein targets:
Daily Intake: Aim for approximately 1.2 to 2.2 grams of protein per kilogram of body weight per day. This range supports muscle recovery and growth.
Post-Exercise: After training or competition, consume a meal or snack containing 0.3 grams of protein per kilogram of body weight to aid in recovery and muscle repair.
Fat: The Healthy Balance
While carbohydrates and protein are essential, don’t forget about dietary fats. Healthy fats, found in foods like fish, nuts, seeds, and olive oil, are crucial for overall health. Here’s the recommendation for dietary fat:
Daily Intake: Dietary fat should make up approximately 20-35% of your total daily calorie intake. Opt for healthy fat sources to support overall well-being.
Hydration: Stay Refreshed
Proper hydration is often underestimated but is vital for maintaining performance and avoiding fatigue. Here are the guidelines for hydration:
Daily Intake: Drink enough fluids throughout the day to stay well-hydrated. A general guideline is to aim for at least 8-10 cups (around 2L) of water daily, but athletes may need more depending on their activity level and climate.
During Training: Hydrate with water or carbohydrate-electrolyte drinks as needed during training sessions. Monitor individual sweat rates to adjust fluid intake accordingly.
Vitamins and Minerals: The Micronutrients
Micronutrients, including vitamins and minerals, are vital for various functions in your body. They help with energy production, maintain healthy bones, support the immune system, and protect against oxidative damage. The increased physical activity of table tennis players can affect their micronutrient needs.
Regular exercise can increase the body’s turnover of B-group vitamins and lead to increased sweating, causing mineral losses like magnesium and zinc. This makes it crucial for athletes, especially those training intensively or for extended periods, to pay attention to their micronutrient intake.
While B-group vitamins are usually easy to obtain from foods like bread and rice, some micronutrients require special attention. For table tennis players, iron, magnesium, and vitamin D are of particular concern.
Iron: Iron is essential for energy production and the formation of oxygen-carrying compounds like hemoglobin. A deficiency can affect endurance and immune function, which is why it’s important for athletes, especially female athletes, vegetarians, and regular blood donors, to monitor their iron levels. Aim to consume slightly more iron than the recommended daily allowance (RDA): 8 mg for males and 18 mg for females.
Magnesium: Magnesium is involved in many enzymatic reactions and plays a key role in energy generation and muscle function. Some athletes don’t get enough magnesium from their diets, so it’s crucial to meet the RDA: 400–420 mg per day for males and 310–320 mg for females.
Vitamin D: Vitamin D isn’t just about bone health; it also affects muscle function and immune responses. Athletes with low vitamin D levels may experience reduced performance. Since table tennis is an indoor sport, players need to consider vitamin D intake. Your body primarily produces vitamin D when exposed to sunlight, but other factors can influence this. To ensure adequate levels, consider supplements or regular sun exposure, depending on your specific situation.
Part 2: Nutritional Ergogenic Aids (Supplements) for Table Tennis
Nutritional ergogenic aids are substances that can provide a competitive advantage by enhancing energy metabolism and optimizing body composition. Let’s explore some of these aids:
Caffeine, commonly found in coffee, tea, cola drinks, and energy drinks, can enhance performance by improving endurance, strength, and mental alertness. In table tennis, where quick reactions and concentration are critical, caffeine can be a valuable tool.
Creatine, a compound found in skeletal muscles, can delay fatigue and enhance maximal power output. Athletes can consider creatine supplementation before competitions, especially if they’ve had insufficient sleep due to travel or competition stress. Guidelines recommend loading with 20 grams per day for 5-7 days, followed by 3-5 grams per day.
Lutein and Zeaxanthin
Lutein and zeaxanthin are carotenoids that protect the eyes and improve visual acuity. In table tennis, where quick visual reactions are crucial, ensuring adequate intake of these carotenoids may be beneficial. Goji berries, green vegetables (spinach, kale), and omega-3 fatty acids are natural sources.
Beta-alanine can buffer exercise-induced acidosis and improve high-intensity exercise performance. Although table tennis primarily relies on aerobic metabolism, beta-alanine might enhance performance during intense rallies. Doses of 6.4 grams per day for 4 weeks have shown benefits.
Part 3: Specific Nutrition Strategies
Nutritional Management of Travel and Jet Lag
International travel can disrupt an athlete’s circadian rhythm and increase the risk of injuries. Melatonin supplements can induce sleep, and caffeine in the mornings can help with circadian resynchronization.
Nutritional Strategies for Competition
Leading up to competition, table tennis players should consume carbohydrate-rich meals to replenish glycogen stores. On competition days, it’s vital to prevent hunger and maintain hydration. A balanced meal with 1 to 2 grams per kilogram of body weight of carbohydrates should be consumed 3-4 hours before a match. Low to moderate GI snacks can be consumed 1-2 hours before a match. During multi-match days, carbohydrate drinks or gels help maintain glycogen levels. Athletes should pay attention to their nutrition during competition to prevent issues like low blood sugar and fatigue.
Nutritional Strategies for Recovery
Recovery nutrition aims to replace nutrients and fluids lost during exercise and prepare the body for the next session. Athletes should consume carbohydrates at intervals for up to 4 hours post-exercise. Protein-rich foods providing 0.3 grams per kilogram of body weight of quality protein should be included. Proper hydration is crucial for optimal recovery. Athletes recovering between matches on multi-match days can benefit from consuming moderate to high GI carbohydrate snacks or drinks. For overnight recovery, a protein-rich meal or snack of about 25 to 40 grams of total protein can maximize overnight protein synthesis and recovery.
Nutrition plays a pivotal role in enhancing the performance of table tennis athletes. A well-balanced diet that provides the right mix of carbohydrates, proteins, fats, vitamins, and minerals is essential. Additionally, nutritional ergogenic aids such as caffeine, creatine, and beta-alanine can offer valuable advantages.
As table tennis continues to evolve and gain popularity worldwide, further research is needed to better understand the specific nutritional needs of players, especially in different regions. With the right nutrition plan, athletes can fuel their way to success, gaining a competitive edge in this exciting sport.
by Manuel Attard M.Sc RD – Sports Dietitian & Nutritionist in Gozo, Malta
In the world of combat sports, athletes strive to achieve the perfect balance between power and weight. This balance is crucial because fighters are typically categorized into weight divisions, and they must meet a certain weight requirement before a competition. This process, known as “making weight,” involves a weigh-in where the athlete’s body weight is verified. The time between this weigh-in and the actual competition can vary greatly, ranging from just 15 minutes to as long as 30 hours.
To gain a competitive edge, fighters would have been manipulating their body weight for years. They use nutrition and training techniques to reduce body fat and increase lean muscle mass. In addition to these long-term strategies, many fighters employ acute weight loss (AWL) methods just before the weigh-in. This practice is commonly referred to as “cutting weight” or “making weight” and temporarily lowers the fighter’s body mass to compete in a lower weight division. Afterward, they strive to reverse the negative effects of this weight loss during the recovery period.
In this article, we’ll explore the various strategies fighters use to cut weight, consider the physiological effects and risks of these methods, and discuss nutritional strategies to optimize performance and health before competition.
Determining the Extent of Weight Cutting
The time available for recovery after the weigh-in significantly influences how much weight fighters can realistically cut. Generally, with more than 12 hours between the weigh-in and competition, fighters might aim to cut up to 10% of their body mass. However, for sports with limited recovery time (around 6 hours or less), they should aim for no more than about 5% body mass reduction. In scenarios with ample recovery time, substantial weight manipulation can be a pragmatic way to enhance competitiveness.
Nutrition professionals and coaches should advise against excessive weight cutting and encourage safer, evidence-based methods. Solely relying on dehydration to achieve these losses is unsafe. Instead, a calculated approach involving gut content manipulation, carbohydrate stores, and body water should be employed.
Acute vs. Chronic Weight Loss Strategies
Professionals working with combat athletes need to be well-versed in both chronic and acute weight loss techniques. They should take a balanced approach that considers both short and long-term goals, performance, and the athlete’s physical and mental well-being.
Common Acute Weight Cutting Strategies and Their Effects
Acute weight loss strategies shouldn’t be the primary method for making weight. Fighters often increase exercise, use dehydration techniques (like saunas or hot baths), restrict fluids and food intake, and sometimes even use laxatives or diuretics in the hours leading up to weigh-in. This can result in fighters losing 5-10% of their body mass in the week before the weigh-in.
However, extreme and excessive acute weight loss can have serious consequences, including severe performance decrements and health risks, including death. Youth athletes are advised to avoid moderate to large acute weight loss strategies and focus on good nutrition practices and training.
There are three main methods of acute weight loss:
1. Manipulation of Gut Content: Dietary restrictions can reduce the mass of intestinal contents and total body mass. While complete fasting and laxatives can be effective, they may also impact energy and nutrient intake and result in performance reductions. Reducing fiber intake is a preferable strategy that doesn’t restrict energy and nutrient intake.
2. Manipulation of Glycogen Content: Manipulating glycogen stores, which are carbohydrates stored for later use in muscles and the liver, is another strategy for acute weight loss. Athletes reduce carbohydrate intake to deplete glycogen stores. Recommendations suggest a low-carbohydrate diet combined with training and a minor energy deficit can achieve a 2% body mass reduction. The exact approach varies among athletes and situations.
3. Manipulation of Body Water: Dehydration is a primary acute weight loss strategy, and fighters can achieve it by consuming less fluid and/or increasing fluid excretion. A 24-hour fluid restriction may result in a 1.5-2% body mass loss. However, passive sweating (like saunas) may affect performance more than active sweating. Combining fluid restriction with active sweating is often a pragmatic strategy. Reductions in sodium intake can also lead to body water losses.
Post Weigh-In Recovery Nutrition
To reap the benefits of cutting weight leading into a competition, fighters must implement a solid post-weigh-in recovery plan. This plan should focus on rehydration, glycogen restoration, and managing gastrointestinal distress.
Rehydration: Athletes should aim to rehydrate to within at least 2% of their pre-dehydration body mass to minimize negative performance effects. They should also consider electrolyte replacement, especially sodium, as sweat losses contain electrolytes.
Glycogen Restoration: While full glycogen stores may not be necessary, glycogen depletion without adequate recovery can affect performance. Post-weigh-in recovery nutrition should include enough carbohydrates to fuel the competition and maximize glycogen stores.
Managing Gastrointestinal Distress: Reducing fiber and fat intake is advisable in the post-weigh-in period to minimize GI discomfort, as reintroducing fiber or consuming large amounts of fat can be problematic.
Pre-competition nutrition involves fine-tuning nutritional status and other non-dietary routines. However, in combat sports, this period often involves reversing weight-cutting efforts. Athletes who weigh in the day before competition can focus on recovery before sleep and competition preparation upon waking. For those weighing in on the day of competition, balancing recovery and preparation can be challenging.
Carbohydrate availability before exercise is essential for performance. The recommendation is to consume at least 1g/kg of carbohydrate in the hours before competition.
Cutting weight in combat sports is a complex process with both benefits and risks. Athletes should be aware of the associated risks of rapid weight loss and follow best practices. Avoiding extreme weight loss, particularly excessive dehydration, is essential to maintain both performance and health. Athletes should develop a well-planned strategy that incorporates familiar practices and continually refine their acute weight loss and recovery methods throughout their careers.
by Manuel Attard M.Sc RD – Sports Dietitian & Nutritionist in Gozo, Malta
Water Polo is played in a pool that’s 30 meters long and 20 meters wide, with a minimum depth of 2 meters. Each team consists of 13 players, including a goalkeeper and 6 field players. A match consists of four quarters of 8 minutes each, excluding time for penalties, time-outs, or goals. The goalkeeper is the only player allowed to touch the ball with both hands at once, and teams have 30 seconds of possession before they must make a goal attempt.
Intense Demands of Water Polo
Water polo isn’t a casual dip in the pool; it’s a physically demanding sport that requires athletes to be in top shape. Similar to many team sports, water polo involves intense bursts of activity combined with physical clashes with opponents. Players perform a wide range of actions, including swimming at various speeds, treading water, wrestling with opponents, and passing, receiving, and shooting the ball.
During a men’s water polo match, players engage in around 100 high-intensity activities and sprints, lasting 7 to 14 seconds each. These bursts of effort are mixed with periods of lower-intensity activity. Players spend an average of 34 minutes in actual play, with a work-to-rest ratio of 5:2.
The demands vary between positions, with perimeter players emphasizing high-intensity swimming and center players focusing more on wrestling.
Goalkeepers have a unique role, spending over 30 minutes performing easy-sculling, around 12 minutes in ready-sculling to maintain a high vertical position, and approximately 3 minutes swimming and passing. They also engage in high-intensity, explosive movements, often following 10-15 seconds of intense exercise, and this is repeated over 40 times in a match.
Meeting the Physical Demands
Understanding the intense physical demands of water polo is crucial for both players and coaches. It’s a game that places significant demands on aerobic and anaerobic energy pathways, meaning that players need both endurance and explosive power to excel.
Players continuously rotate in and out of the game, allowing for individual differences in playing time and, consequently, varying physiological and nutritional needs. Training and nutrition should be tailored to each player’s specific demands to delay fatigue and optimize performance.
Size, Physique, and Body Composition
Male water polo players are often described as balanced mesomorphs. This means they tend to have a balanced combination of muscle mass, body fat, and overall body size. They are heavier compared to elite swimmers, which can be advantageous in a physically demanding sport like water polo. The presence of higher muscle mass and body weight can provide the strength and power needed to excel in the game. Female water polo players, on the other hand, tend to display higher levels of endomorphy, which implies a higher tendency toward storing body fat.
Positional differences in body composition exist among both male and female water polo players. Center players, who are typically positioned close to the goal and engage in physical battles with opponents, tend to be heavier and have higher body fat levels. This extra body mass may offer advantages in terms of holding position and providing buoyancy in the water.
Perimeter players, who require speed and agility, are described as smaller and leaner. Their body composition is tailored to meet the demands of their positions, emphasizing the importance of position-specific physical attributes.
Nutrition Consideration for Water Polo Players
Building Lean Muscle
Having a higher body mass can be advantageous in water polo, especially for those aspiring to reach elite levels. To achieve this, players should focus on building lean muscle. Strength and conditioning workouts are a crucial part of weekly training, and nutrition plays a significant role in muscle development.
Recent research suggests that consuming 20-30 grams of protein immediately after a workout can optimize muscle protein synthesis. Whey protein, which is a fast-acting protein, appears to be beneficial for post-workout recovery.
Carbohydrates for Energy
Carbohydrates are essential for providing energy during training, recovery, and competition. Water polo players should adjust their carbohydrate intake based on their body composition, daily training schedule, and activity levels.
During preseason and intense training phases, when multiple training sessions are common, players should increase their daily carbohydrate intake. This ensures they have enough energy to perform at their best. Younger athletes, those with high energy requirements, and those aiming to gain muscle mass may also need higher carbohydrate intake, typically within the range of 4-8 grams per kilogram of body mass per day.
Conversely, players with higher body fat levels, those recovering from injuries, or those aiming to reduce body fat may require less carbohydrate intake. It’s crucial for to work with a sports nutrition professional to adjust accordingly.
Optimal Pre-Game Nutrition
Pre-game nutrition is crucial for peak performance. Athletes should consume easily digestible carbohydrate foods and fluids before a match. For afternoon or evening games, players should maintain their regular meal schedule throughout the day rather than skipping meals.
During the game, players should consider consuming carbohydrates in the form of sports drinks or gels to maintain brain function and decision-making abilities.
After a game or training session, rapid recovery is vital, especially when there’s a short time between matches or more training. Proper post-game recovery can help replenish muscle glycogen stores and enhance protein synthesis.
A well-organized recovery station with sports drinks, liquid meal supplements, bars, fruits, and other carbohydrate and protein-rich foods can be beneficial. Additionally, players should aim to have a nutritious meal within 2-3 hours after the game to promote recovery.
Although water polo is played in the water, dehydration can still be a concern, especially in warm or humid conditions. Sweat losses and fluid intake should be monitored, and athletes should be encouraged to consume carbohydrate-containing drinks or gels to support carbohydrate intake during training and competition.
Nutritional supplements should be approached with caution. While some ergogenic aids may benefit performance, it’s essential to consult with a sports nutrition professional before using any supplements. The effectiveness of specific supplements, such as creatine and bicarbonate, in water polo remains a topic of ongoing research.
by Manuel Attard M.Sc RD – Sports Dietitian & Nutritionist in Gozo, Malta
Ultra-marathons, those races exceeding the traditional marathon distance of 26.2 miles (42.2 km), have been gaining popularity over the past few decades. These events challenge athletes to run long distances, often in extreme conditions and remote locations. Training and racing in ultra-marathons require not only physical endurance but also careful attention to nutrition.
Nutrition for Training
Daily Caloric Requirements
Several factors influence your daily caloric needs, including your basal metabolic rate, daily activity level, training requirements, body composition, and the thermic effect of food digestion. For ultra-marathon runners, these needs are also affected by body mass, training status, session duration, environmental conditions, and terrain.
To give you an idea, a 50kg female with 15% body fat who runs for one hour at a moderate pace would require about 2004 calories per day to maintain balance. If she increases her training sessions to three hours at the same pace, her daily requirement would be approximately 2726 calories. On the other hand, running at a faster pace for three hours would necessitate around 3423 calories per day.
Training on challenging terrain and in extreme conditions, like heat or high altitude, significantly increases caloric and carbohydrate requirements.
To maintain energy balance, especially on heavy training days, you might need to consume more calories than usual. It’s essential to consider both training and recovery requirements throughout the week unless you have specific weight goals.
For ultra-marathon runners, a typical macronutrient distribution consists of approximately 60% carbohydrates (CHO), 15% protein, and 25% fat to support their endurance training.
When adjusting for body weight, runners engaged in intense training sessions may need between 5-8 grams of carbohydrates per kilogram of body weight per day. Some might even require 7-10 grams per kilogram.
Protein intake is essential for recovery, and athletes should aim for at least 1.6 grams of protein per kilogram of body weight per day. In some cases, up to 2.5 grams per kilogram might be necessary.
Fat intake should range from 1.0-1.5 grams per kilogram per day, but heavier or faster individuals might need closer to 2.0 grams per kilogram to meet their caloric needs.
It’s important to note that these recommendations should be tailored to individual factors, including training duration, pace, and body mass.
Ketogenic diets, which are very high in fat and extremely low in carbohydrates, have gained attention among endurance athletes. While some early studies showed potential benefits for fat oxidation, there’s not enough evidence to recommend these diets for ultra-marathon training. Ketogenic diets can cause fatigue, gastrointestinal discomfort, and may compromise high-intensity performance.
Proper hydration is crucial for ultra-marathon runners, who can lose significant amounts of fluid during training and races. Dehydration can impair performance and health.
Day-to-Day Fluid Intake
For daily hydration needs, drinking to thirst is generally a suitable strategy. Individual fluid requirements can vary, but your body’s thirst sensation is a reliable indicator of when to drink.
Post-Exercise Fluid Intake
After training, it’s essential to replenish fluid losses. Simply drinking to thirst may not be enough at this time, so consider consuming a volume greater than what you’ve lost. Including sodium in your post-exercise drink can enhance hydration.
Hydration Monitoring Strategies
Simple tools like urine color charts can help you estimate your hydration status. Monitoring your hydration is essential for your overall health and performance.
Nutrition For Racing
The considerations for racing in ultra-marathons, including energy and macronutrient demands, energy expenditure, energy intake, carbohydrate versus fat intake, protein intake, and strategies to offset dehydration, are all critical factors to ensure optimal performance and overall health during these demanding races.
Energy and Macronutrient Demands:
Ultra-marathons involve prolonged and strenuous efforts, leading to substantial energy expenditure. Athletes should aim to minimize caloric deficits before and after the race.
Carbohydrate (CHO) availability is crucial for racing. A contemporary CHO-loading strategy (around 10 g/kg/day) in the 48 hours leading up to the race can help maximize CHO stores.
Pre-race meals should be rich in carbohydrates and easily digestible while avoiding high-fat and high-fiber foods to prevent gut discomfort during the race.
Successful completion of ultra-marathons is associated with greater energy and fluid intake. Runners should aim to consume calories during the race to mitigate calorie deficits. Recommended caloric intake during the race varies with distance: approximately 150–300 Kcal/h for races up to 50 miles and 200–400 Kcal/h for longer races.
Persistent calorie intakes below 200 Kcal/h are not recommended. Runners should persevere with feeding even when experiencing nausea, especially in the later stages of the race, to avoid hypoglycemia.
Carbohydrate vs. Fat Intake:
While fat oxidation rates are higher in ultra-marathons compared to shorter races, maintaining an adequate intake of carbohydrates is crucial to prevent early-onset fatigue. Individual strategies for carbohydrate and fat intake vary, but successful runners may require a higher tolerance for both.
High carbohydrate intake rates (up to 90 g/h) may be unrealistic for longer ultra-marathons and can lead to GI distress.
Protein intake during racing is often overlooked but may help mitigate muscle damage and positively influence energy metabolism.Finishers in ultra-marathons tend to have higher protein intake compared to non-finishers.
Runners should strive to consume 20–30 g of protein every 3 hours during the race, balancing it with carbohydrates and fats.
Dehydration can have negative effects on performance and health, particularly in hot and humid conditions. Drinking to thirst is a suitable strategy for shorter and cooler races, but for ultra-marathons, individualized hydration plans based on sweat rates should be determined in advance.
Runners should aim to consume 150–250 mL of fluid approximately every 20 minutes during the race.
Exercise-Associated Hyponatremia (EAH):
EAH is a dangerous condition caused by excessive fluid intake without adequate sodium replacement. Runners should aim to consume sodium in concentrations of 500–700 mg/L of fluid, with higher amounts required in hot and humid conditions. Runners should avoid overhydration, as this will cause dilution of blood sodium.
It’s important for ultra-marathon runners to tailor their nutrition and hydration strategies based on individual preferences, body size, race conditions, and prior experiences. Regular training and experimentation with different foods and fluids can help athletes fine-tune their race-day nutrition plans to optimize performance and minimize the risk of adverse events like dehydration and EAH. Additionally, seeking guidance from a specialized sports dietitian is advisable to develop personalized nutrition strategies.
GI Distress in Ultra-Marathon Running:
GI distress is a common issue among ultra-marathon runners, affecting a significant percentage of athletes, with nausea being a prevalent symptom.
The exact causes of GI distress during ultra-marathon races are multifactorial, but it is often related to reduced blood flow to the GI tract, dehydration, and increased core temperature. These factors can compromise gastric emptying and intestinal transport.
Increased systemic lipopolysaccharides (LPS) from gut bacteria due to intestinal tight-junction disruption can lead to immune responses and GI distress.
Strategies to minimize GI distress include avoiding highly concentrated carbohydrate (CHO) solutions, limiting saturated fat intake, avoiding non-steroidal anti-inflammatory drugs (NSAIDs), and maintaining hydration.
The use of “multiple transportable carbohydrate” solutions (containing glucose, fructose, and/or maltodextrin) can help improve carbohydrate absorption and reduce GI discomfort.
Training the gut and individualized nutritional strategies may help reduce the impact of GI symptoms during races. Low FODMAP diets may benefit those with irritable bowel syndrome (IBS).
Probiotic supplements, particularly Lactobacillus and Bifidobacterium species, may help modify GI microbiota and reduce GI symptoms. However, further research is needed. The inclusion of dietary prebiotic nutrients may support GI epithelial integrity.
Supplements and Medications:
Caffeine is commonly used by ultra-marathon runners due to its stimulant properties. It can enhance endurance performance and cognitive function but should be used carefully to avoid side effects.
The dose and timing of caffeine intake can vary based on individual sensitivity and race duration.
Medium-chain triglycerides (MCTs) and ketone esters have been studied as potential supplements to enhance fat metabolism, but their ergogenic effects in ultra-marathon running are inconclusive.
Vitamins and mineral supplementation do not show significant benefits for ultra-marathon performance unless there is a pre-existing deficiency.
Vitamin C may help reduce oxidative stress and the risk of upper-respiratory-tract infection, but more research is needed.
L-glutamine may support GI epithelial integrity, but further research is needed in the context of ultra-marathon running.
The use of NSAIDs (non-steroidal anti-inflammatory drugs) during ultra-marathons is discouraged due to potential adverse effects and contraindications. Other non-NSAID analgesics (e.g., paracetamol) should be used cautiously to avoid masking pain symptoms that could indicate injury.
Athletes should be cautious about supplement contamination with banned substances when competing in events overseen by anti-doping organizations.
by Manuel Attard M.Sc RD – Sports Dietitian & Nutritionist in Gozo, Malta
Obesity in children is a global epidemic, and the situation locally is particularly grave. In the most recent ‘Health Behaviour in School-aged Children’ study by the World Health Organisation (2020), it was reported that Maltese children aged 11, 13 and 15 had the highest rates of obesity among all the countries surveyed (45 in total). Lifestyle was an obvious culprit and in fact Maltese children were found to have low consumption of vegetables, high consumption of sweets, and high rates of problematic social media use. The approach taken to tackle obesity in a child will vary according to age group.
Infants and Preschool Children
While it is difficult to overfeed a breastfed infant, a bottle-fed infant can indeed be persuaded to drink greater volumes than they require. It is therefore important for the parent of a bottle-fed infant to not always assume that crying signals hunger. The infant can simply be bored, tired, or uncomfortable. It is also essential that formula is made up exactly as per manufacturer’s directions, and that volumes provided are appropriate for age. Infants should be introduced to a cup from about 7 to 8 months of age and bottles should omitted completely by 1 year of age as there is a tendency to consume larger quantities of milk when feeding from a bottle.
Children under 5 who can walk on their own should partake in at least 3 hours of physical activity per day. This includes both light activity such as moving around and playing, and more energetic activity such as running and jumping.
Primary School Children
For primary school children, ownership of the issue needs to be taken by the parents/carers. The parents are the gatekeepers of the child’s food and it is up to them to ensure that the appropriate quality and quantity is being provided. The intervention will have the highest odds of success if the whole family adopts healthy eating patterns, and parents should strive to be role models for the child. The main changes recommend are for the family to reduce the intake of foods high in fat and sugar, replacing them with healthier options such as fruits and vegetables, and ensuring that age-appropriate portions are being consumed.
Goals should be set with the child and rewards for achieving these goals can be motivating. Rewards should be inexpensive non-food items such as a book or a family excursion.
It is also helpful to remove temptations that encourage unhealthy behaviours and provide more opportunities for the child to engage in the desired behaviour. Examples would include not having sugary drinks around the house, going for family walks on the weekends, and always having fruit available as a quick snack.
It is important however to avoid extreme dietary restriction or unbalanced diets, since this could impair the child’s growth and development. It should go without saying that weight-loss supplements are not appropriate in children.
Adolescents are a challenging group and the intervention will only be successful if the teenager himself/herself acknowledges the need for change and is ready to commit to it. Parents should ‘only’ play a supporting role. The main issue at this age is peer pressure for the consumption of fast foods and high calorie snack foods. Strategies used in this age group will involve negotiating acceptable food swaps, portion control, and an increase in physical activity.
Children and young people aged 5 to 18 years should aim for at least 1 hour of moderate-intensity physical activity each day, such as fast walking, playground activities, cycling, and organised sports.
Screen time (watching television, using computers or mobile phones) has become an increasingly insidious problem, and for a lot of children (and their parents) reducing screen time can be the most challenging change to make. According to WHO recommendations (2019), screen time should be avoided in children under 1, while children between 2 to 4 years should be allowed not more than 1 hour of screen time per day. It is recommended that parents designate media-free times for all the family (e.g. meal times) as well as media-free locations at home, such as bedrooms.
Authored by Manuel Attard, M.Sc RD – registered dietitian and nutritionist. This article was first published in the Times of Malta Child Magazine on November 20th, 2021.
When it comes to snacking, we all have our little habits. Some have a sweet tooth, others prefer salty snacks. Some bring snacks to bed, others like to snack while driving. These habits are often ingrained into our routines. Yet, we can outsmart them. Follow some of the following suggestions:
If you’ve just eaten your meal and still feel peckish, distract yourself for 15 to 20 minutes. It takes some time for the brain to receive the signal that we are full. Hence, if you ate too fast, not enough time has passed for the signal to arrive yet. If you give it some time, the urge to snack might pass.
Chew a gum instead of reaching for a snack.
Put snacks in a walkable distance. Don’t have them handy. If you can’t see your snacks, you are less likely to habitually reach for them.
Make snacks look less attractive. For example, if you have some leftovers from a birthday party, wrap the cake in an aluminium foil so you can’t see it. In contrast, your healthy snacks, such as slices of fresh fruits, should be wrapped in a clear foil so you can easily see them.
If you buy things in bulk and come home with super-size packages, re-pack them. If we are given a bigger pack, we are going to eat it. However, if we are given a smaller package, we are going to eat that too, but, it will be half the calories. It’s as simple as that. And, we will still be happy.
Don’t eat out of the package. Bringing a whole tub of Ben & Jerry’s in front of the TV is a bad idea. Serve yourself a portion and eat only your ration.
Make sure you get enough sleep. We can often feel peckish when we are tired. Lack of sleep and stress have been linked to hormonal imbalances that can influence weight gain. Sleep deprivation has also been linked to obesity. So, get your dose of deep sleep and ensure the bedroom is an environment that facilitates good sleep (think temperature, light, noise). Also, try to go to bed at roughly the same time and build a good sleeping routine. This will help you balance out your hormones.
A little note Don’t deprive yourself of comfort foods entirely. Keep them, but just eat them in smaller amounts.
During exercise, our bodies sweat to keep the temperature from rising too much. As a result, we lose water through our skin and unless this is replenished, dehydration can arise.
Dehydration is defined as a body fluid deficit of more than 2 % of bodyweight (e.g. a 2 kg loss in a person weighing 100kg, or a 1 kg loss in a person weighing 50kg). When this happens, blood volume decreases leading to a drop in blood pressure and blood flow, making exercise much harder. Performance (both physical and mental) is impacted, and fatigue will set in faster. It is therefore essential that athletes strive to avoid a loss of body fluid of more than 2%.
Signs and symptoms of dehydration in athletes include:
Dark-coloured urine and lower urine output
Poor mental focus
Confusion and unconsciousness in severe dehydration
Conditions/events that increase the risk of dehydration include:
Warm weather and/or high humidity
Exercising at higher altitudes
Training at high intensities
Concomitant diarrhoea and/or gastroenteritis
Electrolyte supplements or sports drinks can be used during training or competitions of long duration to help prevent dehydration and electrolyte imbalances. These contain glucose and salt that facilitate rehydration and replenish salts lost through sweat. If such drinks or supplements are not available, salty carbohydrate foods such as cereal or salted crackers can be consumed alongside water.
How much should you drink after training?
To fully rehydrate after training, you need to drink about 125 to 150mL for every 100g of body weight lost. This is because the body will keep losing fluids (sweat) even after exercise has stopped. Therefore, if you weigh yourself before and after exercise, and you find that you have lost 1kg, you should aim to drink between 1.25 to 1.5L of fluid to fully rehydrate.
More than 1 in 10 people will experience kidney stones in their lifetimes, most commonly between the ages of 30 and 60. The most common type (and the focus of this article) are calcium oxalate stones, which account for about 80% of cases. Kidney stones have a high rate of recurrence, with about half of those who experience kidney stones having another attack within 5 years. Fortunately, lifestyle changes can be very effective at reducing risk of stone formation.
Drink more water. If you are dehydrated, there is a much higher risk of crystals forming in your urine, eventually becoming stones. It is generally recommended that persons susceptible to kidney stones aim for 3 litres of fluid daily.
Consume more calcium. Since they are called “calcium oxalate” stones, many people restrict calcium intake for fear of increasing the risk. In reality, the opposite is true. The problem with calcium is when there are high levels in the urine, and this is not caused by ingested dietary calcium. In fact, calcium from food binds oxalates in the intestines, and the two are then eliminated with the stools. This way, oxalates are prevented from reaching the blood and eventually urine. It is particularly important to consume calcium with oxalate-containing foods (more on this later). On the other hand, calcium supplements are generally advised against, as these may increase urine calcium levels.
Reduce salt intake. In order for the kidneys to remove salt from the blood (through the urine), they must also excrete calcium in the urine. And as mentioned previously, high levels of calcium in the urine is something we should avoid.
Limit non-dairy animal protein. Diary should be included for reasons stated previously, however, other animal proteins (meat, fish, poultry) should be limited. This is due to the fact that when the body is digesting and metabolising these proteins, it produces acid which is excreted in the urine. To balance this acid, the kidneys will excrete calcium as a buffer. In addition, very high intakes of protein can increase endogenous production of oxalate in the liver.
Increase fruit and vegetables. High intakes of fruits and vegetables have consistently been associated with a lower risk of stones. A possible reason is that these contain a substance called citrate, which can inhibit stone formation in the urine. Citrus fruits, in particular, contain high levels of citrate.
Limit added sugar. Although the reasons are not fully understood, high intakes of added sugars (e.g. from sugary beverages) have been associated with a higher risk of stones.
Avoid vitamin C supplements. The liver can make oxalates from vitamin C, and in fact vitamin C supplements have been shown to be a primary contributor of oxalates in the urine. Note that vitamin C from foods should not be limited because as stated earlier, higher intakes of fruits and vegetables are actually associated with lower risk.
Limit dietary oxalates. Oxalates are found in a range of foods, and a high intake of oxalates from the diet is known to increase oxalate levels in the urine, making stones more likely to form. There are no official cut-offs for the quantities of oxalate that should be consumed, and generally, complicated oxalate calculations are not needed. Avoiding, or greatly limiting, the foods highest in oxalate tends to be enough: these include spinach, almonds, beets, raspberries, and potatoes. Note that this recommendation is only for persons who have experienced kidney stones in the past. One needs to also be careful with supplements and nutritional powders since these may contain extracts of high oxalate vegetables.