Rob Smyth - Personal Trainer - +35387 411 9004

Triathlon Nutrition

Lots of people have contacted me about their nutrition and what should they eat before and after training, so instead of answering 100 emails I have decided to write a blog about it. If  you are looking for personal meal plans you can book in for a consultation, just drop me a mail  This is just advice on nutrition, so please note that results may differ from each body-type and genetics. 

 Meet your daily energy demands

It is not uncommon for us to underestimate our energy demands during training.  Unfortunately, with inadequate fuel in your tank, you will never reap full benefit from your training and actually can heighten your risk for injury.  Depending on daily training volume and intensity, most triathletes require a range of 1500-2200 calories, with male triathletes training for long course triathlons requiring the latter end of these requirements.  If you are looking drop a few pounds of body fat, you should never restrict by more than 1,200 calories per day as this cause  starvation mode or muscle breakdown.  To avoid an energy drain associated with restrictive eating patterns, a smaller restriction of 250-500 calories each day will help you lose 0.5kg of body fat % a week.  On the flip-side, if you need to gain body weight, boost your calorie intake by 250-500  calories daily.


Aim at a balance of 55-60% healthy carbohydrates (fruits, vegetables, whole grains), 15-20% lean protein (soy, no dairy, chicken breast, fish, round steak, turkey), and 20-25% healthy fats (avocado, nuts, seeds, olives, oils), spreading out your total calorie needs into 4-6 smaller meals throughout the day.  Be sure to avoid dietary plans that entail avoidance or restriction of major food groups (e.g., carbohydrate-restricted diets), as they are not balanced and can lead to performance declining nutrient deficiencies as well as potentially serious health consequences. You are training for a triathlon so start eating like an athlete, no paleo diet here please.

To give you an example of what I eat:  As a 82kg male with ~10% body fat, I generally

consume ~2,500 – 3,000 calories during Ironman training which does not include calories that I consume during or immediately after training.  I split my 3,000 calorie daily intake into 4-6 400-700 calorie meals consisting of combinations of carbohydrate and protein and a whole lot of colorful fruits and vegetables.  A typical day of eating for me includes 1) Breakfast: Oatmeal blended with granola, berries, almonds, and coconut milk along with piece of fruit) Lunch: Turkey sandwich with lettuce, tomato, avocado on whole grain bread, vegetable soup or salad and brown rice and a piece of fruit, and low-fat chocolate milk, 3) Afternoon snack: Protein smoothie prepared with berries, juice, and frozen fruit or an energy bar and piece of fruit, 4) Dinner Large salad plus a pasta dish prepared with lean meat, 5) Evening Snack: Small bowl of granola with almonds or maybe some turkey slices or chicken left over from dinner.

Not all of you will be eating this much, but you get the idea on the structure of the diet.


Stay hydrated

Just as important as your nutrition. Aim at drinking 2-3 liters of fluid each day. Drinking more on higher intensity days and hot days, (won’t need to worry about this just yet!)   This does not include your morning cup of Joe or any other caffeinated drink.  In the 1-2 hours prior to your workouts, tap off your fluid tank by finishing one water bottle full of fluid. During your workouts, aim at drinking 500ml of fluid intake every 20 minutes.  Carry a water bottle or fuel belt with you if going on routes where no water fountains are available.  Opt for a sports drink containing electrolytes when your training extends beyond 90 minutes. Your body will be crying for it when you are training for long hours.  Rehydrate with a sports drink after a workout if you find your urine color tending towards a bright yellow color rather than clear or you have lost a significant amount of weight (0.5kg or more)! I take a sachet of electrolytes after every training session to make sure my body replaces the nutrients I lost through sweating. You can get these at any pharmacy, make sure you ask for sports electrolytes, not electrolytes for diarrhea!!


Eat prior to high intensity or long duration workouts.

To ensure optimal energy levels during high intensity or long duration (>90 minutes) For most female triathletes, this equates out to be 45-60 grams of carbohydrates (~200-250 calories) for every hour prior to starting; an energy bar or a piece of whole grain toast spread lightly with peanut butter and topped with 1 sliced banana would be sample snack ideas for 1 hour prior to your workouts.  For most male triathletes, this equates out to be 60-75 grams of carbohydrate (~250-300 calories) for every hour prior to starting; a banana and an energy bar or a small bowl of porridge topped with strawberries and nonfat milk/soy and a glass of orange juice would be sample snacks 1 hour prior to starting your workouts.  Make sure to minimize the amount of fiber, protein, and fat in the meal, as these three nutrients will slow down digestion and potentially cause gastrointestinal problems (e.g., diarrhea) during your workout.  Also, make sure to drink fluids with your meal to ensure optimal absorption of the nutrients.


Be sure to refuel when training longer than >90 minutes.

To optimize fuel usage (burn fat, spare your limited carbohydrate stores), be sure to start refueling after 90 minutes of training.  For every hour beyond 90 minutes, aim at ½ gram of carbohydrate (essential in all races lasting longer than 90 minutes). Again, for most females, this equates out to be 45-60 grams of carbohydrate, which could be replenished by consuming 1 energy gel with electrolyte enhanced water every ½ hour beyond 90 minutes of training.  For male triathletes, an hourly dosing of 60-75 grams of carbohydrates is generally warranted.  This could be fulfilled by consuming an energy gel with electrolyte enhanced water plus 8 ounces of a sports drink every half hour beyond 90 minutes of training.  Opt for sports foods containing small amounts of protein (Accelerade, Perpetuem, energy bars) when training for long course triathlons. At gis stage in training you wont need to worry about this, but when we get into the hard long training session in a few months, please look back at this information.


 After hard training efforts, eat a carbohydrate-protein combination.

Within 30 minutes after finishing, aim at consuming ½ gram of carbohydrate and 1/8 gram of protein per pound of your body weight.  For most female triathletes, a 200-250 calorie snack is appropriate whereas most male triathletes will require closer to 300+ calories for post workout replenishment.  At this time, you could opt for a sports food or you can go for real food, I tend to push for real food as there is a lot of refined sugar in fake food.  Some of my favorite post-workout recovery foods include smoothies with a protein boost, peanut butter/honey/banana sandwiches, chicken & brown rice, cottage cheese/fruit combinations and my favourite…….porridge, any time of the day will do!!  Meal replacement shakes  also provide a convenient nutritional punch when time is at a minimum.