Thinking of Joining USA Triathlon?

Be a part of our 550,000 member community of multisport athletes. Membership benefits include a subscription to the quarterly USA Triathlon magazine, discounts from USA Triathlon partners, inclusion in the national rankings, excess accident insurance at events, and savings at races. To see why you should join or renew today, visit the membership benefits page. Already a member? Login below.

Forgot Password  |  Forgot Member ID  |  Help Renew Membership Become a Member

Muscle Build-Up: Nutrition Guidelines for Resistance Training

By Monique Ryan

All summer you have carefully been timing and portioning your food and fluid intake to promote recovery and optimal energy levels from training session to training session. With the season winding down, you are likely headed toward some more indoor workouts, particularly for strength training. Just as specific endurance training nutritional strategies fueled and hydrated your body to your last race finish, your muscle-building efforts can be maximized with their own unique set of nutritional guidelines.

The Muscle Milieu

Hormones in your body, specifically growth hormone, testosterone, insulin and insulin-like growth factor, all exert control on muscle growth. Food choices can very effectively support your resistance training efforts by appropriately affecting levels of these hormones and providing your body with the proper muscle building tools.

Your primary nutritional focus for resistance training should be actual tissue building, in which muscle fibers increase in diameter, get stronger, and are able to contract more powerfully. Resistance training both breaks down muscle tissue and stimulates muscle fiber growth. The key is to provide the nutritional support that allows the muscle building process to outweigh that of muscle breakdown, a condition referred as positive protein balance. This state of positive protein balance can be achieved through specific food choices, portions and timing.

Whole Day Dosing

Building muscle tissue and triathlon training, even during a recovery cycle, both have specific energy demands. Meeting the energy needs demanded by all the components of your training program is essential to optimize muscle building, so don't cut back on your calories too sharply with a drop in training. It may compromise your daily recovery and hamper your muscle building efforts.

While total energy intake is important, so are the macronutrient components of your diet, namely carbohydrate, protein and fat. In fact, muscle glycogen is an important fuel during weight training and can become depleted, especially when you swim, bike or run on the same day. When resistance training is combined with endurance training sessions lasting over 75 minutes, you can require anywhere from 3.5 to 4.5 grams of carbohydrate per pound of body weight in one day to meet the glycogen demands of several training sessions.

Healthy fats can also compromise anywhere from 20 to 25 percent of your total energy intake. Several studies have indicated that on very low fat diets, blood testosterone levels can be compromised, which can contribute to a state of muscle breakdown rather than muscle building.

Of course, as a major component of muscle tissue, protein is the macronutrient most closely associated with muscle building. Strength training requires higher daily protein needs, but no higher than what should be consumed from a balanced diet for triathlon training. If your total protein intake has been ample all season long, keep it there. However, plenty of good research indicates that the type of protein you consume specifically around weight training, as well as your protein portion and timing is crucial and probably the most important muscle-building nutritional strategy you can practice.

Protein Precision

Several studies have specifically measured the effects of consuming both protein and carbohydrate either before or after weight training. Consuming some protein and carbohydrate prior to your resistance training efforts provides the most effective measured nutrition strategy for enhancing protein synthesis. This pre-training intake seems to produce an even higher response when compared to protein and carbohydrate consumption after resistance training. Researchers believe that as blood flow is directed to muscles during resistance training, so are the amino acids from a protein/carbohydrate drink, making them available in a greater concentration to the muscle.

Though consuming protein prior to weight training is very effective in promoting positive protein balance, you can still consume both protein and carbohydrate after resistance training.  In various studies, researchers have tested the effects of a protein and carbohydrate mixture taken either immediately, one hour or three hours after resistance training. All the timings were found to be similarly effective in stimulating protein synthesis when compared to a placebo, with protein being the most important nutrient of the protein-carbohydrate mix. But be sure to include carbohydrate post-training. While carbohydrate consumed after weight training provides little help, it stimulates the hormone insulin, which in turn allows the protein in the nutritional mix to further enhance protein building.  

Choices and Portions
The type and amount of protein that you consume before and after resistance training is also an important consideration. Based on the types of proteins provided to subjects in various test doses, a high quality protein providing a good dose of essential amino acids is recommended. Aim for 15 to 20 grams of protein and 25 to 40 grams of carbohydrate.

High quality protein sources can be obtained from both supplements and real food. Some good food combinations include dairy sources, such as skim milk and yogurt smoothies mixed with fruit, a turkey sandwich, yogurt with fruit or granola, a peanut butter and jam sandwich, eggs with toast and jam, or an energy bar with the right source and dose of protein. As with your regular training program, whether you choose to consume real food or a supplement is a matter of convenience.

Protein supplements choices are currently available in a variety of forms. Whey protein is an increasingly popular protein supplement. Whey is the component of milk that is separated when making cheese and other dairy products. It is a high quality protein and quickly digested. Whey protein isolate is a lactose-free form. Casein is also a high quality protein, and can be found on labels of many sport supplements. Soy protein, particularly soy protein isolate, is another lactose-free high quality protein and vegetarian option.  Often only a scoop of many of these concentrated protein products is required for the 15 to 20 gram dose. Some products include carbohydrate in the mix, while other pure protein supplements can be mixed with juice.

Other Considerations
Good hydration is also important for weight training. Start all resistance training sessions well-hydrated. During training aim for four to eight ounces of fluid every 15 to 20 minutes. You may even find that a sports drink provides some needed fuel towards the end of your workout. Although creatine phosphate is your primary fuel source when you weight train, muscle glycogen can also become depleted between training sets. After training, replace weight loss with fluid, about 20 ounces for every pound lost.

Many supplements are promoted for their positive effect on muscle building. Unfortunately research has shown many of them not to be very effective. Creatine is one supplement which, when taken properly, can load the muscle with creatine phosphate and can provide more sustained energy for weight training. The ability to improve your workouts then results in greater muscle growth.

Gains in muscle mass and strength takes hard work and the right nutrition plan. Small, frequent doses of high quality protein with carbohydrate, both before and in the hours after your weight training session, is your most effective nutrition strategy. Plan for these snacks within the context of a balanced diet that provides adequate total protein and carbohydrate for recovery from all training sessions.

In Summary

Nutritional strategies to optimize muscle building differ from nutritional strategies for endurance training.

Consuming 15 to 20 grams of high quality protein with 25 to 40 grams of carbohydrate before training is the most effective nutrition strategy for resistance training.

You can also consume this protein and carbohydrate mix in the hour after weight training and again in several hours.

High quality protein sources can be obtained from foods such as turkey, eggs, milk and other animal proteins. Supplements containing whey protein, casein, and soy protein isolate can also be used effectively for convenience.

Monique Ryan, MS, RD is the author of Sports Nutrition for Endurance Athletes, 2nd edition (VeloPress 2007). Click here to view more about the book or purchase. She was a member of the Athens 2004 Performance Enhancement Teams for USA Triathlon and USA Cycling Women’s Road Team. She is owner of Personal Nutrition Designs and offers her sports nutrition “E Program” at