Skeletal Muscle Protein Synthesis: Traditional and Cluster Sets

Study Summary

Traditionally, when performing resistance exercise, repetitions are performed in a continuous manner resulting in a decrease in velocity, and thus power output. "Cluster" set is an alternative to counter the reduction in velocity and power output. Cluster sets incorporate a brief rest (15-30 seconds) between individual repetitions (inter-repetition rest) or group of repetitions (intra-set rest) within a set of resistive exercise. In contrast to traditional set configurations, which result in an almost linear decrease in force, velocity, and power -cluster sets maintain and/or attenuate the loss in power, primarily due to higher velocities. The purpose of this research is to compare the muscle protein synthesis response to acute bouts of cluster and traditional set configurations. Investigators will assess muscle protein synthesis rates before and after acute resistance exercise in 14 resistance-trained males and females (Age: 20-35; back squat 1.5 x body weight; 3 years of resistance training experience). The volunteers are required to be removed (at least six weeks) from all ergogenic levels of nutritional supplements that have previously been shown to affect protein synthesis. Blood and muscle biopsies will be collected as a part of testing. Further, subjects will be required to perform moderate-to-high intensity resistance exercise.

Primary Outcome

Myofibrillar muscle protein synthesis rates will be assessed during the 2hr Postabsorptive period (e.g. non-fed state) and the 5hr postprandial period (e.g. fed state) for both experimental interventions (e.g. leucine and leucine peptide). This will allow us to assess the change in fractional synthetic rate from the Postabsorptive period to the postprandial period.

Interventions

• OTHER Back-squat exercise