Gaspari Nutrition

Clinical Muscle: Is There a Post-workout Anabolic Window?

Feb. 13, 2013

The Great Debate: Is there truly a post-workout anabolic window?

by Sean Felenczak, Staff Writer

The general belief for the need to consume a meal or shake within an hour of your workout has recently been challenged by various nutrition experts. An article from the Journal of the International Society of Sports Nutrition by Alan Aragon and Brad Schoenfeld questioned the validity of the post-workout anabolic window. By referencing numerous studies they were able to develop practical recommendations to help answer the oft asked question. As expected, the answer is not an unmitigated yes or no.

Glycogen is the main source of energy for any resistance training session. The idea behind restoring glycogen immediately after a training session would be to prevent muscle protein breakdown. Theoretically it makes sense, but for someone taking part in a typical bodybuilding-style workout there is little need for immediate restoration. A bodybuilder following a regular meal schedule will sufficiently restore glycogen through their diet. The only situation in which post workout carbohydrates would be beneficial is for endurance athletes or someone performing two-a-day workouts involving the same muscle group.

The other theory behind immediate post-workout nutrition intake is two-fold; promoting anabolism and preventing catabolism. Ironically, the need for post-exercise nutritional consumption is based greatly on pre-exercise nutritional consumption. Generally speaking, a sufficient pre-workout meal has enough of an anabolic effect to last well into the post-exercise period. Your next scheduled meal or shake (likely one to two hours after working out) is sufficient enough for recovery and anabolism. The exception to this rule is for those who train fasted or well past their previous meal (e.g. 4-6 hours prior). In this situation, it would be a good idea to consume a meal or supplement containing both protein and carbohydrates to combat muscle breakdown and promote muscle synthesis.

The studies cited by Aragon and Schoenfeld all have their strengths and weaknesses. Since there are so many variables that effect muscle growth it is nearly impossible to find ‘the perfect study.’ Some studies advocate the benefits of post-exercise protein consumption, yet they include pre-workout protein consumption as well. Other studies did not include pre-workout nutrition, but the muscle growth and recovery shown could be based solely on greater overall protein intake and not timing.

With that being said, Aragon and Schoenfeld still recommend high quality protein (0.4-0.5g/kg of lean body mass) both pre and post workout within about 3-4 hours of each other (this can be extended to 5-6 hours if it is a particularly large meal). Due to the lack of definitive answers regarding the anabolic window, this basically takes on the ideology of ‘better safe than sorry.’ At the very least, you can rest assured that you don’t have to speed home to eat a meal or chug a shake seconds after your last set. The diet example given is a basic guideline and should be tailored to your individual needs and preferences. The full journal article can be found here

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