Effects of Resistance and Endurance Training on Synthesis of Individual Muscle Proteins in Young and Older Adults

Effects of Resistance and Endurance Training on Synthesis of Individual Muscle Proteins in Young and Older Adults

Effects of Resistance and Endurance Training on Synthesis of Individual Muscle Proteins in Young and Older Adults

Loss of skeletal muscle strength and skeletal muscle mass occurs with of aging. This are-related decline in skeletal muscle mass and skeletal muscle strength is a major underlying factor contributing to many of the metabolic disorders and frailty of the investigators rapidly expanding aging population. Endurance (aerobic) and resistance exercise training programs have been shown to effectively reverse the age-related decline in metabolic and contractile muscle functions. The investigators will measure synthesis rates of individual muscle proteins in 36 each of young (18-30 yrs) and 36 older (> 65 yrs) people to determine their response to 8 weeks each of endurance, resistance, combined endurance and resistance training, or placebo exercise training. Hypotheses. to measure fractional synthesis rates of multiple muscle proteins and identify those that are enhanced by an endurance exercise program to determine whether changes in protein synthesis in response to endurance exercise programs are dependent on age to measure fractional muscle synthesis rates of multiple muscle proteins and to identify those that are enhanced by a resistance exercise program to determine whether changes in protein synthesis in response to resistance exercise programs are dependent on age

Participants will perform 8-weeks of no exercise, followed by an additional 8-weeks of combined endurance plus resistance exercise training.

Participants will perform 8-weeks of endurance exercise training. Participants will train 5 days per week for 60 min at 65% of VO2 peak.

Participants will perform 8-weeks of resistance exercise training. Participants will train 4 days per week for ~60 min. Two days will focus on lower body resistance training and two days will focus on upper body.

Participants will perform 8-weeks of no exercise (control), followed by 8-weeks of combined endurance and resistance training. Participants will endurance train 5 days per week for 30 min at 65% of VO2 peak and resistance train 4 days per week for 30 min.

The investigators will determine the change from baseline in skeletal muscle protein synthesis. Measurments will be performed at baseline and following 8 weeks of exercise training.

The investigators will determine the change from baseline in mitochondrial function. Measurments will be performed at baseline and following 8 weeks of exercise training.

Inclusion Criteria: Healthy 18 to 30 or >65 years Males and Females Exclusion Criteria: Regular Exercise Program Smoking Cardiometabolic Disease (diabetes, cardiovascular disease, thyroid disorders) Drugs known to impair metabolic function (beta blockers, steroids) Allergies to lidocaine Physical disability that precludes exercise

Irving BA, Lanza IR, Henderson GC, Rao RR, Spiegelman BM, Nair KS. Combined training enhances skeletal muscle mitochondrial oxidative capacity independent of age. J Clin Endocrinol Metab. 2015 Apr;100(4):1654-63. doi: 10.1210/jc.2014-3081. Epub 2015 Jan 19. Erratum In: J Clin Endocrinol Metab. 2023 Aug 18;: