Protein powders are now a staple in lots of gym routines and have helped fuel a $10 billion market, yet many people keeping a tub in the kitchen still don’t really know what these supplements are doing inside the body.
For regular exercisers, protein supplements can seem almost magical: they’re often used to curb appetite, support recovery, and help build or maintain lean muscle.
Protein is also one of the three main macronutrients your body relies on. It supplies nine essential amino acids you can’t make on your own, and those are involved in a huge range of normal, healthy functions.
However, evidence indicates that a lot of powder users may be prioritizing the wrong detail. Rather than obsessing over scoop size, other choices—especially when protein is taken—can be more influential for training results.
A typical scoop of whey protein (the most common type) contains about 25g of protein—just under half of many people’s recommended daily intake. But research suggests the timing of intake may matter more than simply pushing the total higher.
To explore this, researchers ran a double-blind, placebo-controlled trial in 2019 involving 18 young men. Participants were split into two groups: one received a protein supplement, while the other received a placebo.
The team aimed to reconcile earlier findings that hinted supplemental protein benefits during exercise might level off around 20g, while other studies suggested consuming protein both before and after training could better support gains in lean muscle.
Previous work often focused on athletes eating large amounts of protein during demanding training blocks. This study instead turned the question toward more typical gym-goers.
In research published in the Journal of Exercise Nutrition & Biochemistry, both groups were instructed to keep their diets steady and to train three times per week, following a balanced weights plan that targeted upper and lower body.
Every four weeks, participants visited the lab after fasting for eight hours. The supplement group had a whey drink before their warm-up, completed a roughly 50-minute session with progressive нагрузки, cooled down, and then had a second protein drink.
Altogether, this meant 40g of protein across the pre- and post-workout window.
Afterward, both groups completed blood testing and other measurements such as blood pressure and muscle circumference. Researchers also tracked strength progression based on the weights lifted and reps completed across sessions.
Overall, muscles improved across the board, but the standout changes were in the chest and thighs, which had ‘significantly increased in the protein intake group’ across the 12-week program.
Notably, those particular increases in size were only observed in the protein supplement group, even though the placebo group still improved strength and endurance.
The researchers also reported that supplements seemed to be useful specifically around training sessions, and that increasing protein intake on rest days did not offer additional advantages.
“These findings support that the ingestion of whey protein immediately before and immediately after workouts can promote improvements in strength and hypertrophy,” the study concluded.
After monitoring participants’ protein from normal meals—where the placebo group typically ate more protein overall—the authors added that ‘the composition and timing of protein intake are more important than the total amount.’