The Anabolic Window
It has been a long held belief, by many bodybuilding trainees, that it is neccesary to ingest an easily digestable protein immediately, or soon after a bodybuilding workout. The “anabolic window” as it is known, is variously touted as being between 30 mins and 2 hours duration post workout.
The rationale for ingesting protein within this anabolic window, is that it supposedly maximises the reponse to training, by increasing the assimilation of muscle.
It does this because apparently during the anabolic window, the body is particularly primed to accept food and utilise it towards the aquisition of lean muscle mass.
The timing of this in regard to how soon it is required post workout is a hotly contested subject however.
Post-workout nutrition requires two things:
Protein for protein synthesis, and carbohydrates to replace glycogen (and to enhance the role of insulin in transporting nutrients into cells). Insulin needs to be coupled with the availability of amino acids. Research indicates that the amino acid leucine is optimal in this regard.
However, research on trainees participating in nutrient timing studies, has indicated that total protein intake is the primary factor influencing muscular hypertrophy.
Furthermore, research results would certainly seem to refute the commonly held belief that the timing of protein intake in the immediate pre – and post-workout period is critical to muscular adaptations.
Some trainees however, still believe that if you have’nt ingested a protein shake within 45 mins of training, you can waive goodbye to any muscle gains. Some even believe that your muscles will shrivel from catabolism. Unless you are in a fasted or severely calorie restricted state this thinking is nonsense.
The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg/day. However, these values are based on the needs of sedentary individuals, and are intended to represent a level of intake necessary to replace losses, and hence avert deficiency; they do not reflect the requirements of hard training individuals (Schoenfeld et al).
Muscular adaptation has indeed been shown to increase in line with total protein ingestion, up to a threshold optimum level beyond which further ingestion will have no effect. This threshold limit is thought to be around 2.2 g per kg of lean mass for natural athletes.
This highlights the importance of consuming higher amounts of protein in the diet, when the goal is to optimise exercise-induced increases in muscle mass.
The immediate intake of dietary protein pre and/or post-workout however, would at best appear to be a minor consideration.
Ingesting a protein drink post workout maybe beneficial, and certainly wont hurt you. However you will still gain a substantial amount of size even if you delay post-workout nutrition, so long as your overall diet, training and recuperation are on point. You certainly can’t rely on a post-workout protein shake and the mythical “anabolic window” to deliver most of the protein you ingest each day.
Rather than focusing on the non-existent magical window of growth, instead ensure that you meet your dietary requirements throughout the day. Plan your food intake around 25-30 grams of protein every few hours, and consume adequate amounts of carbohydrates throughout the day to maintain energy levels.
Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training
The effect of protein timing on muscle strength and hypertrophy: a meta-analysis