A study done at the Sports Medicine Research Unit led by Esmark and colleagues found that there was a correlation between when study participants took protein and their muscle growth. The study focused on elderly men, as a natural loss of muscle mass occurs with age. The researchers wanted to know if the effects of resistance training were altered or assisted with varying post-workout protein intakes.
With age, both men and women lose muscle mass. This leaves the individual weaker and less able. With hopes of reducing the risks associated with weaker and more fragile bodies, Esmark and his team decided to find if and how timing of intake could improve the effects of training. While it is known that resistance training aids in the synthesis muscular proteins in people of all ages, and that an intake of protein aids in the molecular process, the timing of intake remains unresolved.
Thirteen men, averaging 74 years old with a BMI of 25, or normal, part-took in the study. They engaged in a 12 week program with resistance training 3 times each week. They were split into two groups, both receiving the same dosage of 10g of protein, as well as some carbohydrate and fat in each serving. The first group was given the dose immediately after training and group two was given the dose 2 hours after training.
To determine the effects of training and protein intake, MRI's, DEXA scans, muscle biopsies and strength measures were taken of each participant. Their food intake was also followed for 4 days and insulin response to glucose was tracked.
Between the two groups, the first was found to have a greater increase in muscle mass than group two. Neither group experienced any differences or changes in insulin response. Dynamic and isokinetic strengths were recorded and while both groups showed increases, group one showed consistently more gains (46% compared to 36 %, on average).
This study exemplifies the effect that protein intake has on muscle growth and muscle strength. The importance of taking protein at the right time and in the correct quantity is also arguable according to the results of this study.
B Esmark, JL Anderson, S Olsen, EA Richter, M Mizuno, M Kjaer. "Timing of post exercise protein intake is important for hypertrophy with resistance training in elderly humans. Journal of Physiology. 2001.