TriDiet: Triathlon Nutrition for Peak Performance

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As a sports nutritionist I am often asked, “What should I eat to compete at my best?” The answer to this is complicated and depends upon several factors, including:

1. Type of training activity (i.e. endurance vs. power)
2. Duration of activity
3. Stage of training and/or intensity of training (i.e. off or in-season, rest or competition)
4. Personal food preferences

While there is no one answer or diet plan that will work for every triathlete, there are some guidelines that all triathletes can follow when planning a peak performance diet.

Components of a Peak Performance Diet:
The components of a PPD center around three main things: Quantity, Mix, and Timing.

1. QUANTITYQuantity refers to the amount of food and drink a triathlete should consume, or more simply, their total calorie needs.

Skimping on calories? This may cause your body to break down muscle protein, which can hinder performance.

A triathletes total calorie (or energy) needs vary due to changes in training load and intensity, but meeting daily calorie needs is essential to not only providing the energy needed to train and compete, but also to spare the breakdown of muscle protein.

Triathletes should work with a sports nutritionist to determine what their individual calorie needs are for a) training, b) competitions, c) rest days, and d) variations of all three.

One way for triathletes to gauge if they are meeting their daily calories needs is by keeping a weekly performance and weight log. If weight is remaining stable and performance doesn't decline, this is a good indication that daily calories needs are being met.

2. MIXMix refers to the combination of protein, carbohydrate, fat and fluid that should make up the daily caloric intake of a triathlete.

When choosing foods and drinks, a triathlete should focus not only on getting the right quantity of carbohydrate, protein, fat and fluid but also the best quality. Making quality food choices includes choosing more nutrient dense (nutritionally dense) food options. For example, a potato is a carbohydrate that can be prepared in many ways. Triathletes following a peak performance diet plan should choose the baked potato over fries, since the baked potato is more nutrient dense (i.e. has more nutrients for the amount of calories it contains). Both low-fat milk and lemonade are fluids, but milk is a more nutrient dense fluid choice, because in addition to water, it provides the body with high quality protein, vitamins, minerals, and carbohydrate.


Carbohydrate Protein Fat
Whole grains
100% juice
Lean beef
Soy foods
Vegetable oils

3. TIMINGTiming refers to when food and fluids are consumed.

While meeting calorie needs and choosing the best quality foods and fluids are important, timing of food and fluid intake can be the key to a peak performance diet.

Food and fluid intake should be timed appropriately to ensure that:

  • Carbohydrates are available for energy and glycogen replacement
  • Fluids are available to hydrate and rehydrate
  • Protein (amino acids) is available for muscle repair, maintenance, and growth

Timing is everything when it comes to a peak performance diet. Consuming foods and fluids at the appropriate time will ensure high energy levels, quicker recovery, and nutrition support for muscle growth, maintenance and repair. Follow the guidelines below for optimal nutrient timing.

2-4 Hours BEFORE training sessions

  • Drink at least 16 ounces of fluids
  • Consume a high carbohydrate, low fat, moderate protein meal
  • Choose familiar foods
  • Consume about 125 – 300 grams of carbohydrate

Sample meal: 125 g carbohydrate, low fat, moderate protein – Turkey sandwich with 2 slices of bread, 1 slice cheese, 2 slices turkey, 1 tsp. mayonnaise, lettuce and tomato. 1 cup pasta with vegetables and fat free Italian dressing. 1 banana.

30-60 Minutes BEFORE training sessions

  • Consume about 0.3 – 0.5 grams of carbohydrate per pound of body weight
    Ex. 0.3 g carbohydrate for a 145 pound triathlete
    1 small banana, 16 oz sports beverage
  • Choose familiar foods
  • Choose foods low in fiber
  • Drink 8-16 ounces of fluid 15 minutes before exercise

DURING training sessions > 1 hour

  • Drink 4 – 8 oz of fluid every 15 minutes
    · 4% – 8% carbohydrate concentration
    · 0.5 – 0.7 grams sodium/liter
  • Consume 30-60 grams carbohydrate per hour:
    · 16 oz sports drink, 2 Large bananas, most energy bars, 9 graham cracker squares

Recovery AFTER training sessions

  • Maximum glycogen replacement rate occurs within 2 hours after exercise
    · Takes 24- 48 hours to fully recover used glycogen
  • Eat a high carbohydrate, low fat, moderate protein meal
    · 0.45 grams carbohydrate per pound of body weight immediately
  • Post-strength training: consume a high quality protein like milk, egg, or chicken
Peak Performance Diet Plan – Triathlete Tool Box

QUANTITY: Estimated calorie needs

REE X Activity Factor = Calories Needed

How to Calculate Your REE (resting energy expenditure)

Males: multiply weight in pounds by 11
Females: multiply weight in pounds by 10

How to Choose an Activity Factor:
Sedentary (complete rest day, mainly sitting) = 1.3
Light activity = 1.6 (males), 1.5 (females)
Moderate activity = 1.7 (males), 1.6 (females)
Very Active = 2.1 (males), 1.9 (females)
Extremely Active = 2.4 (males), 2.2 (females)

Carbohydrate Needs Protein Needs
Exercise Time (gms/lb body wt) Activity Level (gms/lb body wt)
1 hr /day 2.7-3.2 Elite endurance 0.5-0.7
2 hr /day 3.6 Intermittent (cross training) 0.6-0.8
3 hr /day 4.5 Power athletes (mid-season) 0.5-0.6
4 hr /day 5.4-5.9 Power athletes (mid-season) 0.7-0.8

gms= grams, lb= pound, mod=moderate

Fluid Intake Guidelines

Within 2 Hours of exercise – 14-22 oz
Within 10-20 minutes of exercise – 7-10 oz
During exercise – 6-12 oz every 15-20 min
After exercise – 3c for every pound of wt loss

Fluids Choices:
Less than 60 minutes choose plain, cool water
Greater than 60 minutes choose water + carbohydrates & electrolytes (i.e. sports drink)

KEY: oz=ounce; min=minute; c=cup; wt=weight

TIP: there are 8 oz in 1 cup and 12 oz in a can of soda

The Bottom Line
A peak performance diet plan is an essential part of every triathlete's training. While no two triathlete diet plans are alike, every triathlete can follow the guidelines for developing a peak performance diet plan. Follow the 3 P's:

1. Prepare – work with a Sports Nutritionist to develop your plan.
2. Practice – incorporate your plan into your training sessions.
3. Perfect – keep a log of what you consume and how you feel when training and competing. Use this log to perfect your own peak performance diet plan!

*Originally published 2006

Jaclyn (Jackie) Maurer, PhD, RD is a sports nutritionist for
Jackie holds two advanced degrees in Nutritional Sciences from the University of Arizona, most recently completing a Doctoral Degree in Nutritional Sciences with a minor in Physiology in May 2005. Jackie has competed across all levels and distances in running. Beginning in junior high, she continued to race cross-country and track and field through high school and college (University of Arizona Team Captain). Jackie has extensive experience working with athletes, ranging from collegians to post-collegians to professional and Olympic level athletes. Relying on this unique sports nutrition experience with multisport athletes, Jackie is focused on assisting triathletes to improve their performance.

Trismarter provides the highest quality in-person and internet-based triathlon coaching and sports nutrition services for all triathletes, from novice to elite. These services are based on a superior understanding of the sport as well as the specific needs of every individual athlete with whom we work. Unique to the triathlon world is our highly successful Tri2Lose triathlon training and weight loss program. Join Trismarter to get fit, race hard, and enjoy this incredible sport of ours! Contact us today at or visit our website:


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