Chronic resistance training has been shown to increase muscle cross-sectional area, volume and strength. Individuals participating in a resistance training program may wish to consume protein supplements to aid recovery and maximise adaptation. Furthermore, antioxidants have been shown to aid recovery from acute bouts of exercise. However, the effect of antioxidants combined with protein on long term-training adaptation is not fully understood. This study will combine measures of muscle size, muscle strength and function, and the underlying changes in muscle metabolism in order to assess the effect of consuming a combined protein-antioxidant supplement during a 30 session resistance training program.
Supplemental protein ingestion is an established method for augmenting gains in fat free mass, muscle strength and muscle cross sectional area following a period of resistance exercise training. In addition to protein, supplements high in polyphenols such as berry and pomegranate extract are believed to be an effective method of reducing soreness and facilitating recovery following a single bout of resistance exercise. However, whilst polyphenols are shown to facilitate recovery from a single session of resistance exercise, their effect on adaptations to repeated bouts of resistance exercise are unknown. Asking this question will allow a detailed investigation of the mechanisms by which protein-polyphenol ingestion may affect adaptations to resistance exercise training when compared to a non protein or polyphenol containing placebo, which is an important yet underexplored area
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Enrollment
32
A placebo beverage will be consumed both post-exercise and pre-bed
A protein-polyphenol beverage will be consumed both post-exercise and pre-bed
University of Exeter
Exeter, Devon, United Kingdom
Change in cross-sectional area of quadriceps muscle group
The cross-sectional area of the muscles comprising the thigh after 30 training sessions will be compared to pre-training values. This will be measured using MRI.
Time frame: After 30 training sessions (approx. 10 weeks)
Change in quadriceps muscle group volume
The volume of the muscles comprising the thigh after 30 training sessions will be compared to pre-training values. This will be measured using MRI.
Time frame: After 30 training sessions (approx. 10 weeks)
Change in knee extensor isokinetic total work
Bilateral knee extensor isokinetic total work will be assessed before and after the training program by quantifying work completed over 30 isokinetic quadriceps contractions on an isokinetic dynamometer.
Time frame: After 30 training sessions (approx. 10 weeks)
Change in maximal isometric peak torque
Knee extensor isometric peak torque will be assessed before and after the training program using an isokinetic dynamometer.
Time frame: After 30 training sessions (approx. 10 weeks)
Change in maximal isokinetic peak torque
Knee extensor isokinetic peak torque over 3 repetitions will be assessed before and after the training program using an isokinetic dynamometer.
Time frame: After 30 training sessions (approx. 10 weeks)
Change in muscle protein synthesis assessed using the stable isotope Deuterium Oxide
The enrichment of deuterated alanine (from the deuterium oxide heavy water stable isotope tracer) in vastus lateralis biopsy samples will be measured relative to the non-deuterated alanine. The change over 48 hours will be measured pre- and post-training to calculate a fractional synthesis rate (% day).
Time frame: After 30 training sessions (approx. 10 weeks)
Perceived quadriceps muscle soreness:
Soreness will be assessed at the start of each training session using a validated visual analogue scale (VAS)
Time frame: After 30 training sessions (approx. 10 weeks)
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