To understand and effectively put into practise good nutrition for performance, an athlete first needs to appreciate the importance of a nutritionally sound day-to-day diet, as well as grasping 3 key areas of effective sports nutrition – pre-exercise, during exercise and post-exercise nutrition.
Regards the general day-to-day diet, re-thinking meal timings and moving away from the standard 3 meals a day scenario is something triathletes greatly benefit from. Adopting a 5 small meals a day approach works very well, spreading energy intake evenly over the course of the day. This allows individuals to effectively fit meals and snacks around training sessions, maintain good energy levels, recover well, and importantly too, doesn’t over-tax or over-stress the digestive system.
Here is a quick at-a-glance daily diet for a triathlete or any other endurance athlete…
Breakfast or pre-exercise:
Bowl of porridge or muesli topped with yogurt, banana or berries
Mid-morning or post-exercise
2 poached eggs on wholewheat toast OR a 2-egg vegetable filled omelette
Baked sweet potato topped with baked beans, and salad
A large chicken or salmon main course salad, using a good portion of protein, together with 6-7 raw vegetable or salad foods of your choice.
Wholewheat or rye bread sandwich filled with lots of salad, tomato, cucumber, sliced avocado, and flaked tuna, sliced egg or sliced turkey
Mid-afternoon or pre-evening exercise
Fresh fruit and seeds or nuts
Supper or post-exercise:
Grilled, baked or poached fish, chicken or turkey with plenty of steamed vegetables, and a cooked brown rice or quinoa
How much do I need to eat?
It helps to have a good awareness and understanding of the estimated energy (calorie) requirements of endurance athletes, and most specifically, requirements for carbohydrate and protein. Nutritional and calorie needs of athletes vary widely, and depend on factors such as body weight and training load, as well as sex and genetics, and the quality of the diet. According to the American College of Sports Medicine (ASCM), calorie (energy) intakes for endurance athletes range anywhere from 2-3000 kcals a day for women, and 3-5000 kcals for men. If energy intakes fall too low, i.e. similar to that of non-active individuals, fat and lean tissue loss can occur, and often to the detriment of the athlete, in health and performance terms. Those who eat too little, or eat a poor diet in general, often suffer with immune-related problems such as frequent colds and flu, a failure to recover on a consistent basis, and increasingly put themselves at risk of injury and illness.
N.B. Due to female athletes lower calorie intakes compared to men, and often-higher iron and calcium requirements, nutrient rich food sources of these minerals should be eaten regularly. Excellent food choices include dark leafy greens, such as kale, spinach, & watercress, broccoli, almonds, sunflower seeds, pumpkin seeds, dried figs and apricots, yogurt, cottage cheese, beans, and chickpeas.
Quinoa – Quinoa is in fact a seed, and higher in protein than most grains. Mineral-rich and low GI, quinoa is undoubtedly a top carb for triathletes.
Butternut Squash – A carb-rich, flavoursome nutritious vegetable that can be steamed, mashed or roasted
Apples – an excellent fruit carbohydrate with pectin fibre to slow down the release of sugar into the bloodstream.
Sweet potato – this orange-fleshed starchy carb is a winner in the athlete’s kitchen. Boiled, baked, steamed or roasted, it’s nutrient-rich and packed with slow-release energy.
Barley – Used in place of rice, cous cous or pasta, barley has the lowest GI of all the grains! Its full of B vitamins for energy metabolism, easy to cook, and easy to digest.
Banana – Bananas are an exceptional fruit carbohydrate for active triathletes. They contain both simple and complex sugars, are fast-digesting for quick energy, and nutrient-rich too.
Oats – Oats are a top breakfast food, versatile, easy to prepare, and without refined sugars and oils! Rich in energy, B vitamins and minerals, oats are a winning carbohydrate.
Less nutritious carbs!
White bread – Stripped of fibre and much of the wheat’s natural nutrition, most white breads are both high GI and highly processed.
White sugar – Refined sugars creep into a vast majority of modern-day food products resulting in high sugar consumption and consequent weight gain and poor health.
Instant mashed potato – manufacturing processes used to create “instant” produce a high GI, reduced nutrition, food.
Double Choc muffin – shop-bought muffins are simply too high in refined sugars and fats to be considered healthy!
Sugary cereals – Many commercial cereals are too high in added sugar to be considered healthy. These are not the best breakfast choice for the athlete.
Doughnuts – Loaded with refined sugar and fat, doughnuts are likely to leave you feeling heavy, sluggish and nutrient-depleted.
Eating before training provides the necessary fuel and fluid to get the most out of the upcoming training session. It can also give the athlete confidence and peace of mind that they’re suitably energised.
What to eat and when, largely depends on the time of the training session. If it’s first thing in the morning, a light snack 1-2 hours before is sufficient. Exercise later in the day calls for a meal 3-4 hours prior. In addition, sufficient fluid should be taken to maintain hydration. Food should be relatively high in carbohydrate to maintain blood glucose, moderate in protein, and composed of familiar foods that are well-tolerated by the athlete. A meal should also be low in fat and fibre to minimise any potential gastrointestinal distress. For many, eating prior to exercise simply satisfies gnawing hunger pangs, although hunger is not always a good indicator of low body stores of carbohydrate, rather, just a feeling that the stomach is empty. What to eat, how much to eat, and when to eat, depends very much on what time of day you decide to train. Training very early in the morning leaves little time for a pre-workout meal 3-4 hrs before. In these instances, either a snack or liquid meal such as a milk smoothie or even a latte 1-2 hrs prior can suffice, especially if the session is 60 minutes or less. In situations when there is no time at all to spare before training, training on an empty stomach for sessions 60-90 minutes is perfectly feasible, and the norm for many athletes. For some who are well-trained, and efficient at utilising fat stores as energy, water, tea or an espresso is the preferred pre-workout fuel. Workouts that are an hour or less can successfully be fuelled on just water. The body has sufficient carbohydrate stores to fuel at least 60 minutes of exercise (sometimes more than this). However re-fuelling soon afterwards is crucial to recovery and energy replenishment. However, every individual is different, and with all pre-exercise meals, the athlete must experiment to find the timing, amount and meal make-up that best suits the individual needs.
During the night, the body’s carbohydrate stores become depleted, mainly the stored carbohydrate (glycogen) in the liver. Replacing lost carbohydrate with food or fluid, not only fuels a morning exercise session, it also helps to optimise performance, and recovery too. An early morning breakfast meal becomes more important when an athlete is training 2 or more times a day.
A normal or familiar sized meal (containing 200-400 mainly carb calories) eaten 1-2 hours before a morning workout is sufficient for most athletes. If there is only an hour to spare, a small meal, or liquid smoothie will likely be better tolerated. Good meal choices include a bowl of oats or oatmeal, or porridge with banana and yogurt, a fruit and yogurt smoothie, or a simple bowl of fresh fruit and yogurt. These sorts of meals are easy to digest, contain a mix of low and medium GI carbohydrates, with a little added protein and minimal fat, all of which will top up liver glycogen stores, and help keep blood sugar levels in check. Incidentally, oats and oatbran can simply be soaked overnight in water, and don’t necessarily need cooking, which is perfect if you are preparing breakfast in a hotel room, or similar. Bananas are particularly good as they are easily digested and provide three natural sugars – sucrose, fructose and glucose. With the combined fibre, bananas provide both an instant, and sustained boost of energy.
Many swimmers and triathletes find it hard to eat solid foods prior to a swim session. Often carbohydrate drinks or smoothies work best, or a small bowl of cooked porridge. Other alternatives include fresh fruits such as apples and bananas, which are fast-digested and absorbed.
Daytime and evening training sessions…
Ideally, a moderate-sized meal should be eaten 3-4 hours prior to a daytime or evening training session. The focus should be on carbohydrate with small-moderate amounts of protein. The focus should be on low GI carbohydrates, e.g. oats, sweet potato, brown rice, quinoa, barley, and vegetables. Good meal examples include oat-based cereals and banana, mixed rice and tuna, scrambled eggs on wholegrain toast, sweet potatoes with beans and salad, turkey or egg salad in a wholemeal pitta, or a bowl of chicken and vegetable stew. A small amount of protein in meals reduces the overall glycaemic index of the meal, which leads to a steadier release of glucose into the bloodstream during the upcoming session. Protein can also be used as a back-up fuel and also helps to stimulate protein resynthesis after exercise.
It is most important to remember that food only becomes useful to the body once it has been digested. Therefore, there has to be sufficient time for a pre-exercise meal to fully digest. The hormone insulin rises following a meal (especially a carbohydrate -rich meal), which stimulates carbohydrate metabolism, increases muscle glycogen breakdown, inhibits fat metabolism, and encourages fat storage. So, leaving enough time for insulin to lower to resting levels, means better sparing of muscle glycogen and heightened fat metabolism during the early part of a training session, or race. If you need something close to the start of a session or race, choose a piece of low-sugar fruit such as an apple or banana. Although there is little scientific evidence to show that carbohydrate taken during the hour immediately before exercise has negative effects on performance, it’s still not wise to take on board too much food 20-30 minutes before the start, as blood sugar may well drop just as you set off. However, every individual will respond differently to carbohydrate foods, so DO practise in training, and use these guidelines and suggestions as a starting point.
Nutrition during exercise
During exercise water, carbohydrate (plus protein and electrolyte salts) provides the muscles with the golden fuel for exercise. There are many types of carbohydrates, or sugars commonly used for fuelling during exercise, but the most appropriate are those that enter the bloodstream easily and quickly. These include the simple sugars glucose, fructose, sucrose, maltose and galactose, as well as longer-chained sugars such as maltodextrin. Most reputable sports drinks use a combination of these, e.g. maltodextrin, glucose, and fructose, at a recommended concentration of 4-8% carbohydrate. Recent research from Jeukendrup and colleagues at Leeds University found that a combination of glucose and fructose worked very well, enabling athletes to oxidise carbohydrate at higher rates than previously recorded.
With shorter training sessions (i.e. less than 60 mins), carbohydrate ingestion is not necessary. Even with sprint distance races, it is the body’s fluid needs that are of prime importance, rather than food/carbohydrate needs. However with long training sessions (2/3 hours +) as well as Olympic, half and full ironman races, food and fluid needs have to be satisfied, and taken on board. The most critical point for athletes to understand is that both these components of fuelling (food and fluid) must be consumed at rates that the body can absorb and fully utilise, without creating gastrointestinal upset.
Research tells us that most male and female athletes happily absorb about 1g carbohydrate per minute or 60-70g carbohydrate per hour (Jeukendrup et al., 2005), which is around 240-280 carbohydrate calories. Ideally this should be spread over the hour(s) in 2-3 ingestions. Many athletes (especially heavier males) will argue they can take on board more than research indicates, and while this simply illustrates our individual uniqueness, there will be a ceiling of somewhere in the region of 300-400 calories an hour, depending on factors such as a person’s size, gut function, and environmental conditions too. Once again, the athlete must practise in training, with types and amounts of food, and drinks that work best. It is also worth understanding that during long training sessions or races, there will almost always be a negative energy balance during exercise, i.e. energy expenditure exceeds energy intake. So even when consuming carbohydrate at regular intervals throughout long exercise sessions, an athlete will not match calorie output, i.e. energy expenditure. This negative energy balance is compensated partly by pre-race, or pre-session high carbohydrate meals over preceding days, as well as the natural contributory energy metabolism from fat and protein. Eating and drinking too much prior to, and during training, racing only results in gastrointestinal upset.
Carbohydrate-enriched energy drinks, and gels taken with sufficient water, provide the perfect solution to satisfying both fluid and energy needs, as well as being relatively easy on the gut. Eating small amounts of solid food (aside from being based on personal choice regarding taste and gut sensitivity) is a viable option and helps to avoid hunger pangs, or feelings of emptiness. Eating solid foods when racing, such as fresh or dried fruit, energy bars or bagels, should however be well-practised during training and in simulated race sessions.
N.B. New foods or new food/fuelling strategies should never by tried during a race.
For those keen to try natural gels, one of the most natural on the market are Honey Stingers, each providing 29g CHO from honey, with added B vitamins, potassium and sodium.
Other gels you may want to explore…
Mulebar Kicks contains agave nectar, fruit juice concentrate and brown rice flour syrup – http://www.mulebar.com/fuel-gels.asp
Clifshot gels include maltodextrin, cane juice & fruit juice – http://www.thefeedstation.com/gels/clif-shot-gels-24-pack.html
With any type of gel consumed during a race, 200-300 ml water needs to be taken on board as well.
For a home-made energy/electrolyte drink, mix 1 litre of water, with ¼ tsp of sea salt (this provides a natural balance of all electrolytes), 40g (2 tablespoons) of honey, and lime juice to flavour.
Certainly during racing and competition, the cycling section of the race provides the best opportunity to ingest fluids and carbohydrates i.e. water plus energy bars or gels, or energy drinks. Carbohydrate snacks can also be consumed, as long as fluid intake is also adhered to. However, it is very wise to wait until the heart rate, and breathing have settled down or have stabilised on the bike before eating or drinking anything, except water. Once the body has settled, small sips of an energy/electrolyte drink can be taken. This often helps to avoid any gut distress, which is common if an athlete consumes too much too soon. The optimum CHO concentration of energy drinks is 7% (i.e. 7g per 100ml) and the most current advise for endurance athletes and triathletes (male and female) is to aim to achieve a carbohydrate intake of 60 – 70g every hour in mild or moderate conditions, and 50-60g per hour in hot conditions. Many past studies, however, have shown that intakes of 22-40g still result in enhanced endurance performance, so nothing is completely set in stone. The research by Asker Jeukendrup, PhD, found that when a combination of carbohydrates is ingested (e.g., glucose and fructose) oxidation rates of slightly more than 100 g/h could be achieved if larger amounts (i.e. more than 140g CHO per hour) of carbohydrates are consumed. However, whether this results in better performance remains unclear, and any carbohydrate solution that is very concentrated is highly likely to cause gastrointestinal discomfort.
Following scientific guidance regarding optimal carbohydrate intake per hour during exercise, here is a practical strategy to follow…
If using a carbohydrate sports drink, try to consume 300ml of 7% CHO solution drink every 20 minutes. If you like gels, these contain around 29/30g CHO, so 1 every 30 mins should suffice. Always drink 300ml of water with gels. Solid foods can replace gels, and should also be combined with water (not sports drinks). One medium banana contains 20g CHO (= to a sports drink serving), and naturally contains electrolyte minerals such as potassium. A mini box of Sun Maid raisins contains 30g CHO (= to a gel), and raisins are naturally high in antioxidants, and contain electrolyte minerals such as sodium and potassium, so also make a good solid food choice. Practise with all liquid and solid food choices in training. In calorie terms, you are aiming for approximately 100 calories every 20 minutes. It is worth noting that more calories can generally be tolerated on the bike than during a run.
During running, and on run section of races, many athletes find solid foods (and sometimes gels) difficult to tolerate. Sports drinks are usually the preferred choice. If an athlete needs to take on board carbohydrates, it often helps to slow the pace, to better accommodate consumption of carbohydrate, nutrients and water.
As with running, the best fuel and fluid to take on board during swimming is water or carbohydrate drinks, should the athlete need carbohydrate. Water is sufficient for sessions less than 60 minutes.
Energy or sports drinks should all contain electrolytes, and especially sodium. Asker Jeukendrup and colleagues recommend a concentration of 30â€“50 mmol/L of sodium for optimal absorption and to prevent hyponatraemia. Hyponatraemia is an electrolyte disturbance, and specifically defines low levels of blood sodium. In the case of athletes, it is caused by prolonged sweating coupled with consuming large amounts of water or fluid with low or no sodium. Drinking very large amounts of water over a short space of time can also cause hyponatraemia. Drinking too much water literally dilutes the blood, as the water pushes vital electrolyte salts out of the body. When sodium levels fall below a critical level (135 mmol/L), symptoms such as nausea, headache and vomiting may occur. As it worsens, convulsions and even coma may occur.
To avoid hyponatraemia, electrolytes should be replaced during long endurance exercise, in addition to water. Well-formulated energy drinks (e.g. Gatorade) contain optimum carbohydrate and sodium concentrations, although as ever, any sports drinks need to be tested in training, to gauge individual gut tolerances, and responses. Sodium tablets are, in most cases, unnecessary. Researchers in Cape Town, in 2006, found that sodium tablets were not necessary to preserve serum sodium concentrations in athletes competing for 12 hours in an Ironman triathlon.
Sweat rates and fluid needs
Fluids should be consumed at a level exceeding the athlete’s sweat rate. Sweat rate is highly individual, as well as being dependent on factors such as ambient temperature, wind factor, humidity, clothing, and fitness level. This high individual variability means that every athlete should work out his or her own sweat rate, and at regular intervals due to changes in fitness levels. This is most easily accomplished by recording fluid loss after a 1 hr hour training session. This should ideally be done in a cool, as well as a hot environment, as sweat rate will be different for each.
How to calculate fluid needs
Weigh yourself naked beforehand. Complete an hour-long training session (taking no fluid on board), and then strip down and weigh yourself again after the session. The weight lost is fluid loss, or sweat rate. Of course this exercise can be done for longer sessions, with taking fluid on board. However the athlete must make sure to account for the fluid drunk in the end calculations.
N.B. One kilogram of weight lost, is equal to one litre of fluid lost. It is not uncommon (especially for males) to lose between 0.8-1.4 litres of fluid per hour. To stay hydrated, an athlete needs to drink more than he or she has lost, to avoid dehydration. This means aiming to lose no more than 1% total body weight.
The range of fluid absorption rates varies, as individuals have very different capacities to absorb fluid. For most athletes, absorption rates will be in the region of 600-800ml per hour. Some athletes may be able to absorb a litre or more.
Tips to stay hydrated
* Begin each exercise session in fluid balance.
* Have a glass of water with all meals and snacks.
* Before training, drink 200-600 ml of fluid.
* Devise a hydration plan for exercise sessions longer than 30 minutes.
* Sports drinks or water are the best fluid options during exercise.
* Aim to rehydrate effectively after exercise.