Post Workout Nutrition

October 17th, 2007 by Paul Johnson

The post-workout meal is one of the most important meals of the week. After your workout, a lot of different hormones are released in response to your vigorous workout. What nutrients you give your body postworkout, will be important in causing a cascade of hormone reactions, to set the tone for the rest of the day. Traditionally bodybuilders consume high protein and carbohydrates immediately post workout, but lets see what science says on the issue.

Post Workout Nutrition Research Studies:

While the conerstone of post-workout nutrition, traditionally has been a high carb drink immediately after a workout, many bodybuilders now advocate protein added also. A study (Am J Physiol Endocrinol Metab. 2005 Apr;288(4):E645-53. Epub 2004 Nov 23) showed increased protein synthesis from amino acid plus carbs over the carb only. Another study (J Appl Physiol. 2004 Feb;96(2):674-8. Epub 2003 Oct 31) also found net positive body protein balance, was better with amino acids than carbs post workout. A study published in Diabetes. 1999 May;48(5):949-57, showed insulin had 3 times greater effect on amino acid transport.  Researchers concluded that low amino acid availability, could limit the insulin's effect on muscle protein synthesis after exercise.

There is some conflicting results, on the factor of protein added to carbs, on glycogen synthesis and recovery. I believe one reason why there is some conflicting results can be found in research study published in Am J Clin Nutr. 2000 Jul;72(1):106-11. In the study glycogen synthesis was increased from either, protein + carbs drink or simply increasing the carb intake, compared to the normal carb drink group. The protein plus carbs and the higher carb group, had a higher insulin response than the normal carb group. In other words, adding protein and aminos to a post workout drink, just may be a expensive form of glucose(once it's converted in the body). Therefore, the amount of carbs to cause a adequate insulin spike, is the main factor in glycogen synthesis and recovery. I should also add that, glycogen recovery is of little importance to bodybuilders. Our main focus, is post workout nutrition's effect on protein synthesis and anabolic hormone production.

Carbohydrates are important post workout because of the hormonal changes they cause with insulin. IGF-1 releases when growth hormone and insulin are high. After a workout your insulin will be low, but your growth hormone levels should be high. By having a carb drink post workout, you will spike your insulin and cause the release of IGF-1 as a result. IGF-1 is extremely important in muscle growth. Another reason carbs are important is in controlling cortisol. Cortisol starts producing heavily near the end of a workout and we know cortisol production is blunted by spikes in insulin, which high carb intake causes.

A study in J Appl Physiol. 1998 Oct;85(4):1544-55 showed differences in hormonal changes for days, between the placebo and those supplementing carbs and protein for pre and post workout meals. In this study, growth hormone and testosterone were elevated immediately post workout. On day one, growth hormone increased more for the supplemented group. Cortisol production post workout was blunted by the supplement group. IGF-1 was also increased for the supplement group on days 2 and 3. This study shows that what you eat before and after workout, can effect your hormonal response for multiple days.

What should I eat for my post-workout meal?

You should have carbohydrates and protein as soon as possible post-workout, preferably in a liquid form. These days, many bodybuilders are now advocating low glycemic carbs after workout. These bodybuilders believe the massive high glycemic carbs post workout, leads long term to increased insulin tolerance(decreased insulin sensitivity). Maintaining insulin sensitivity long term, is crucial because it leads to more muscle gains, fat loss, and reduced risk for diabetes. Many bodybuilders have reported no reduced gains, resulting from a switch to low glycemic carbs postworkout.