Exercise and Bracing for Muscle Atrophy
(HYPAT Trial)

Recruiting in Palo Alto (17 mi)

Age: 18 - 65

Sex: Male

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Waitlist Available

Sponsor: McMaster University

No Placebo Group

Trial Summary

What is the purpose of this trial?Skeletal muscle plays several different roles in the promotion and maintenance of health and well-being. The loss of muscle mass that occurs with aging, chronic muscle wasting diseases, and physical inactivity puts people at an increased risk of frailty and becoming insulin resistant, and therefore imposes a significant burden on health care spending. Resistance exercise participation has proven particularly effective for increasing muscle mass and strength. This effectiveness can be used by health care practitioners in a rehabilitation setting to promote the recovery of individuals who have undergone involuntary periods of muscular unloading (i.e. limb immobilization caused by a sports injury or reconstructive surgery). However, there is large variability in the amount of muscle mass and strength that people gain following participation in resistance exercise. Some individuals fail to increase the size of their muscle (low responders) whereas others show vary large increases in muscle size (high responders) in response to the same resistance training program. People also show differences in the amount of muscle tissue they lose when they have a limb immobilized. To circumvent variability across individuals, the investigators utilized a within-person paired Hypertrophy and Atrophy ('HYPAT') strategy that reduced response heterogeneity by \~40% (Available at: https://ssrn.com/abstract=3445673). Specifically, one leg performed resistance training for 10 weeks to induce hypertrophy, whereas the other leg underwent single-leg immobilization for 2 weeks to induce atrophy. The primary goal of the study will be to gain insight into the molecular responses to an acute period of single-leg immobilization and resistance exercise (8 days). The investigators will use an integrated systems biology approach to monitor the individual rates of over one hundred different muscle proteins.

Eligibility Criteria

Healthy males aged 18-30 with a BMI of 18.5 to 30 can join this study. They must be able to consent and not have muscle or bone diseases, serious illnesses, uncontrolled hypertension, diabetes, or take meds affecting protein metabolism. Non-smokers who don't drink excessively or exercise more than twice a week are eligible.

Inclusion Criteria

I am a healthy male aged between 18 and 30.

Your body mass index (BMI) is between 18.5 and 30.0.

Able and willing to provide informed consent

Exclusion Criteria

I am taking blood thinners.

You use tobacco products.

You drink more than 21 units of alcohol per week.

+6 more

Participant Groups

The trial is testing the effects of knee bracing and unilateral resistance exercise training on muscle size changes due to loading (exercise) and unloading (immobilization). It aims to understand individual molecular responses over an acute period using advanced proteomics techniques.

2Treatment groups

Experimental Treatment

Group I: Unilateral Resistance ExerciseExperimental Treatment1 Intervention

One leg will undergo 4 sessions of unilateral resistance exercise, over the course of 8 days. Specifically, participants will be asked to perform leg press and leg extension.

Group II: Unilateral ImmobilizationExperimental Treatment1 Intervention

One leg will undergo 14 days of single-leg immobilization, by means of a removable knee brace.