With three disciplines to consider, it's easy to make mistakes when you're eating and drinking during training and racing. That's the bad news. The good news is that it's easy to avoid triathlon's common nutritional pitfalls if you plan ahead and follow these tips for effective refuelling in the build-up to your next race.
The problem: You avoid fatty foods
Many triathletes are body conscious and try to eliminate fat from their diets. If you avoid foods such as red meat and dairy products, you will miss out on vital micronutrients such as calcium and iron. We all need a certain amount of fat in our diets to make hormones. Fat in foods is also an important source of the fat-soluble vitamins A, D and E, while essential fatty acids will help to keep your immune system in peak condition.
Don't avoid fats completely. Some dairy foods, meat and meat products can be high in fat and saturated fat but careful choices can still keep your fat intake down. Choose lean cuts of non-processed meats, remove visible fat or skin from poultry and stir-fry, bake, poach or steam. Red meat is an excellent source of iron, which helps transport oxygen around the body, and zinc, which is essential for a healthy immune system.
Skimmed milk, cottage cheese and low-fat yoghurts provide a tiny amount of fat but are rich in calcium and are also a good source of protein. While oily fish such as salmon, sardines and mackerel are rich in essential fatty acids that are also important for the body's immune system.
The problem: You don't drink when you swim
Just because you're exercising in water doesn't mean you aren't sweating and becoming dehydrated.
Take a drink with you to every training session, including swimming. When you exercise your muscles produce heat, this extra heat has to be removed to avoid an increase in core-body temperature. Sweating is often the most important way for your body to lose heat when exercising but this uses up precious body water. Dehydration can impair performance and cause you to decrease the intensity of, or shorten your training session. For a moderate training session lasting up to one hour, water or dilute squash is fine - drink according to thirst and comfort but you might aim for around 50ml to 100ml every 15 minutes.
The problem: You miss main meals
Fitting in training before work, at lunch time or after work often means missing your usual meal times. Even if you substitute a nutritious balanced meal with a bowl of cereal or toast, you'll still miss out on important elements of a nutritious meal, such as vitamins, minerals, essential fats, antioxidants and protein.
If you are training at lunch time, make sure you have a larger breakfast than usual which includes fruit, and a mid-morning snack, which also includes fruit. After training have something to eat and drink immediately - bananas and fruit smoothies make great energising snacks - and then lunch. If you become hungry mid-afternoon, choose a fruit yoghurt or a teacake or scone. If you are training in the evening, aim to have your main meal for the day at lunch time or eat a bigger lunch than usual and have a mid-afternoon snack to ensure you are adequately fuelled for your training session. After training, have a lighter meal but make sure there is a balance of vegetables, salad or fruit and carbohydrate and protein.
The problem: You pack in protein
If you are consuming a high amount of protein, you might be cutting down carbohydrate-rich foods to stay within your energy requirements. For triathletes though, carbohydrate-rich foods are essential. New research shows that most people, including endurance athletes, easily meet their protein requirements and don't consciously need to eat more. You require around 1.2g to 1.4g of protein per kg of body weight - so a 60kg triathlete should be consuming 72g to 84g of protein per day. A study of male road cyclists found protein intakes of 94g to 172g per day and the average UK man consumes 88g per day.
Make carbohydrates the biggest part of meals and base snacks on fruit or carbohydrate-rich foods. Three modest portions of protein-rich foods per day (usually at each main meal) will meet your needs.
The problem: You skip breakfast on race day
Arriving on the start line empty is likely to seriously dent your performance. It isn't so much of a problem for sprint races, but as the distance you race becomes longer, skipping breakfast will have more of an impact on your performance.
Eat a carbohydrate-rich meal, containing plenty of rice, pasta or potatoes, the night before the race to top-up your glycogen stores. Aim to eat breakfast around three hours before the race and have a couple of slices of white toast or a bowl of low-fibre cereal. An energy gel around 30 minutes before the start will ensure your glycogen stores are topped up. Ensure the drinks bottles on your bike contain carbs (see Rocket Fuel, right) or have something to eat, like a banana or an energy gel, once you are settled on the bike. The length of the event will dictate how much you eat and drink but you should aim for at least 30g to 60g of carbs every hour.
The problem: You don't practise race-day nutrition
If you don't plan your race-day nutrition you could, at worst, go into a race without any food or drink with you, or at best you refuel with food and drink you've not tried before. You might end up running out of fuel or unable to tolerate a product, which can result in cramp, nausea or diarrhoea.
Having a plan about what you are going to eat and drink, when and where, will give you confidence for a successful race. In the same way that you practise transitions, you should know what you are going to eat and drink on race day from the moment you wake to beyond the finish line. Plan what you are going to eat, how much, and when and practise this in training. Always take extra food and drinks to a race too - you can always take them home again after if you don't need them.
The problem: You eat too close to training
It's really important not to eat just before training as this can lead to problems in your running and swimming sessions. You may experience gastrointestinal problems - for instance, feeling discomfort due to undigested food in your stomach could lead to vomiting and diarrhoea if you are doing physical exercise.
Some people can tolerate eating a small snack 10 minutes before running while others have to eat three hours before training. Experiment to find out what works for you. Try to allow two to four hours after a large meal before exercising. A high-carbohydrate snack 30 to 60 minutes before exercise can be OK, but avoid bulky, fibre-rich carbohydrates like wholemeal bread and breakfast cereals.
The problem: You don't have time to refuel after training
Eating and drinking after a training session are just as important as cooling down and stretching - refuelling helps the body to recover in preparation for your next session by replenishing glycogen stores and providing protein to repair any muscle damage.
In the four hours following a strenuous session, glycogen storage rates are at their highest and this is the best time to refuel. Aim to eat 1g to 1.2g of carbohydrate per kg body weight per hour in each of the four hours following a hard session. For a 50kg female triathlete this means 50g to 60g of carbohydrate per hour and a total of 200g to 240g of carbohydrate in the four hours following a hard training session. This can be a series of small snacks - liquids and solids - as opposed to large meals.
The problem: You burn fat instead of carbs
As an endurance athlete, you rely heavily on your body's stores of carbohydrate to fuel training and racing. But many training techniques focus on ways to increase the body's fat-burning potential because we have so much more energy stored as fat. During lower intensity, long-training sessions the body still uses glycogen stores at the same time as it burns fat, just not as quickly. During high-intensity training the body relies heavily on stored carbohydrate, but once it has been used up, it is almost impossible to continue training or racing at the same intensity.
Carbohydrate is king, and 60 to 70 per cent of your energy intake should come from carbs. An 80kg male triathlete training for one to two hours a day needs around 400g to 560g of carbohydrate per day. All meals and most snacks and fuel while training and racing should be based on carbohydrate-rich foods.
The problem: You don't refuel on rides
The effects of dehydration will probably be the first thing you notice. A loss of one to two per cent body weight (as water) can impair performance and decrease the intensity of, or shorten your training sessions. A moderate cycle of more than 90 minutes will use up your body's carbohydrate stores (glycogen). If they run out, you will 'hit the wall' or 'bonk'. This means you have insufficient fuel to continue cycling at the same pace; you may feel light-headed and dizzy and unless you eat soon your ride will be over.
Take two 750ml drinks bottles with you on training rides of two or more hours, and more in hot weather. Sports drinks will supply you with carbs - aim for 30g to 60g of carbs per hour but if you don't like the taste, you can make your own (see Rocket Fuel, right). Try energy bars and gels with plain water, or bananas and dried fruit also make great portable snacks.
The problem: You don't want to pee in public
During a race, or even a long training ride, if toilet facilities are limited many triathletes try to drink as little as possible. This lack of fluid can rapidly lead to dehydration, which, as we have seen, cuts your energy levels and affects your performance.
We all have to answer the call of nature sooner or later. Try to plan your route so that it includes public toilets or cycle to a friend's house where you can visit the bathroom before cycling home again.
Power your training and racing with these home-made sports drinks.
These contain a little carbohydrate and salt. They are ideal for providing fluid rapidly and replacing salt losses, but don't provide much energy. Try a hypotonic drink for low-intensity training sessions lasting less than one hour.
• 100ml full-sugar fruit squash + 900ml water + 1g (1/5th teaspoon) salt
• 250ml unsweetened fruit juice + 750ml water + 1g (1/5th teaspoon) salt
These are absorbed faster than water, replace lost fluid and salt and provide energy in the form of carbohydrate. Isotonic drinks are ideal for training sessions lasting longer than one hour.
• 500ml unsweetened fruit juice + 500ml water + 1g (1/5th teaspoon) salt
• 150ml high juice squash + 850ml water + 1g (1/5th teaspoon) salt
• 50-70g table sugar or glucose powder + 1lt water + 1g (1/5th teaspoon) salt