The Effects of Heavier- and Lighter-load Resistance Training on Arm and Leg Muscle Mass in Young Adult Women — FHALL  

Skeletal Muscle Hypertrophy Clinical Trial

Official title: The Effects of Higher- And Lower-Load Resistance Exercise Training on Leg and Arm Skeletal Muscle Mass in Healthy Young Adult Females

Status Completed

Clinical Trial Summary

When you perform weightlifting, your body makes new proteins within your muscle. These new proteins can increase the size of the fibers within your muscle to make your muscle larger, a process called hypertrophy. The common convention surrounding gains in muscle mass and strength are that higher-loads (i.e. heavier weights) used for fewer repetitions are better for increasing strength and lower-loads (i.e. lighter weights) used for higher repetitions are better for increasing muscle mass. However, recent research has found that when higher- and lower-loads are used when participants exercise until volitional fatigue (i.e. cannot perform another repetition), muscle mass and strength increases are similar regardless of using a higher- or lower-load. Many of these studies have examined this effect in males with fewer studies examining the effects of higher- and lower-load training in females when assessing changes in muscle mass, strength, and muscle endurance.

Further, it has been shown that there is substantial individual variation in response to resistance exercise training where individuals can be broadly categorized as higher- or lower-responders to resistance exercise training. This study aims to explore how the muscle mass, strength, and muscle endurance of females are impacted by both higher- and lower-loads while also exploring how individuals may respond to the training interventions.

Clinical Trial Description

The study will be a total of 12 weeks in total duration. Weeks 1 and 12 will include testing assessments of skeletal muscle mass, muscle strength, and muscle endurance. Weeks 2-11 will be comprised of the resistance training intervention wherein participants will train thrice weekly at the Chan Gunn Pavilion research laboratory at the University of British Columbia.

Resistance training sessions will include unilateral knee extensions and unilateral dumbbell bicep preacher curls with each being performed for three sets. Limbs assigned to train with higher-loads will perform between 8-12 repetitions per set and limbs assigned to train with lower-loads will perform between 20-25 repetitions per set. Participants will rest 90 seconds between sets and 120 seconds between exercises. Each exercise will be performed in its entirety before moving on to the next.

Participants will also be supplemented with whey protein which will be ingested twice daily during the resistance training phase. ;

Related Conditions & MeSH terms

• Hypertrophy
• Skeletal Muscle Hypertrophy

• NCT number: NCT04547972
• Study type: Interventional
• Source: University of British Columbia
• Status: Completed
• Phase: N/A
• Start date: January 5, 2021
• Completion date: August 12, 2021