Do You Need Less Protein Intake on Days that You Don’t Train?

The truth on how much protein intake you really need to build muscle.


Most bodybuilders know that on training days they need to up their protein intake to support increased recuperation and gains in lean muscle mass. The major goal of bodybuilding is to increase lean muscle mass. In order to build lean muscle mass, muscle protein synthesis needs to exceed protein breakdown over time (i.e., a chronic positive protein status). Previous research has shown that higher protein intake diets and resistive exercise have additive effects on lean body mass maintenance, or even lean body mass gains in a caloric deficit. Higher protein diets and supplemental exercise tend to increase weight loss, but have greater effects on body composition through the preservation of lean body mass while increasing fat loss.


The muscle protein synthesis acute response from exercise is a dose-response, depending upon exercise intensity and workload. There is a delay in protein synthesis after exercise of about 45 minutes to an hour, where muscle protein synthesis rises sharply (2-3 fold) between 45 and 150 minutes. The increased sensitivity of muscle protein synthesis, in response to essential amino acid intake after exercise, can last up to 24 hours – where some studies have even documented up to 72 hours. Most research studies have found that resistance-trained men consumed protein intakes of 1.8–2.7 g/kg/ while engaging in a rigorous strength-training program. A new study set out to determine the protein needs of bodybuilders that had been training for three years on their “off” days.  Some bodybuilders may eat less protein on their “off” days, but this may be a mistake. The study tested a group of bodybuilders 48 hours after their last bout of resistance exercise and were fed various doses of protein on their days that they were resting. Shockingly, the study found that even when the bodybuilders were not training, their bodies had a high protein requirement.  It also demonstrates that protein intake remains elevated at least 48 hours post-workout. The estimated average protein requirement was found to be 1.7-2.2g/kg/day, even though they had not trained for two whole days! This means, even though you may not be training on a particular day, the muscle recovery and building process is still occurring, as a result of your previous workout.



Bandegan, A, Courtney-Martin, G, Rafii, M, Pencharz, PB, Lemon, PW. Indicator Amino Acid–Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance. The Journal of Nutrition. Published online 8 February 2017.