The goal of this clinical trial is to determine the effect of maximal mental effort combined with low-intensity resistance training on strength and neuromuscular function in older adults. The main questions it aims to answer are: * Does low-intensity resistance training in combination with maximal mental effort increase strength more than low intensity resistance training alone? * Does low-intensity resistance training in combination with maximal mental effort improve neuromuscular function more than low intensity resistance training alone? Participants will be randomly assigned to 1 of 3 groups: * Low intensity resistance training * Low intensity resistance training with maximal mental effort * Control Researchers will compare groups to determine differences in changes in strength, neuromuscular function, and body composition.
Participants in both training groups will perform 8 weeks of low intensity, whole-body resistance training. Participants in the control group will participate in all testing procedures but not perform any training. Participants from all groups will be instructed to otherwise maintain their normal physical activity levels and dietary habits. All training sessions will be supervised by research personnel at a Kennesaw State University fitness center. Participants will complete 2 training sessions per week for 8 weeks. Each training session will last about 45-60 minutes and consist of 5 exercises, including both multi-joint (leg press, chest press, back row) and single-joint (knee extension, bicep curl) exercises. Participants will perform 2 sets of 15 repetitions for each exercise for the first 2 weeks, then volume will be increased by progressing to 3 sets for the remaining 6 weeks. There will be a 60-second rest interval between sets and a similar tempo will be used between groups. Both training groups will perform the same training protocol, but participants in the maximal mental effort group will mentally urge their muscles to contract maximally during each repetition. That is, despite using a low intensity, participants will imagine the feeling of maximal muscle contraction of the primary muscles during each repetition. Several measures of strength, neuromuscular function, physical function, and body composition will be measured before and after the training or control period.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
75
This training intervention will be 8 weeks of low intensity resistance training, including whole-body and isolated muscle exercises, where participants will perform maximal mental effort by imagining maximal muscle contraction during each exercise.
This training intervention will be 8 weeks of low intensity resistance training, including whole-body and isolated muscle exercises.
Kennesaw State University
Kennesaw, Georgia, United States
RECRUITINGChange in isokinetic strength of the knee extensors at 60 degrees per second
Dynamic strength of the knee extensors contracting at a constant velocity
Time frame: Baseline, Week 8
Change in isokinetic knee extensor muscle activation as measured by electromyography amplitude
Electromyography root mean square during isokinetic contraction divided by root mean square during isometric contraction
Time frame: Baseline, Week 8
Change in isometric knee extensor strength as measured by newton-meters of torque
Isometric strength of a muscle
Time frame: Baseline, Week 8
Change in knee extensor muscle activation as measured by electromyography amplitude
A measure of the capacity at which the muscle is activated by the nervous system
Time frame: Baseline, Week 8
Change in motor unit firing rate as measured relative to the motor unit recruitment threshold
A measure of how nervous system input produces force output during an isometric contraction
Time frame: Baseline, Week 8
Change in motor unit action potential size as measured relative to the motor unit recruitment threshold
A measure of how nervous system input produces force output during an isometric contraction
Time frame: Baseline, Week 8
Change in handgrip strength as measured in kilograms of force
Upper-body strength as measured by a handgrip dynamometer
Time frame: Baseline, Week 8
Change in walking speed as measured by time taken to walk 4 meters
Measure of lower-body physical function
Time frame: Baseline, Week 8
Change in chair rise performance as measured by number of chair rises performed in 30 seconds
Measure of lower-body physical function
Time frame: Baseline, Week 8
Change in bicep curl strength as measured by load lifted in pounds
Maximum dumbbell load lifted successfully throughout the range of motion of a bicep curl
Time frame: Baseline, Week 8
Change in dynamic strength of the lower body muscles during the leg press as measured by load lifted in pounds for 5 repetitions
Measure of dynamic strength during the leg press exercise
Time frame: Baseline, Week 5, Week 8
Change in muscle composition as measured by ultrasound-derived grey-scale analysis
Echo-intensity value derived from grey-scale analysis is indicative of amount of non-contractile tissue in muscle
Time frame: Baseline, Week 8
Change in skeletal muscle size as measured by ultrasound-derived cross-sectional area
Size of a muscle
Time frame: Baseline, Week 8
Change in fat mass as measured by kilograms
Amount of fat tissue a person possesses estimated by bioelectrical impedance analysis
Time frame: Baseline, Week 8
Change in fat-free mass as measured by kilograms
Amount of non-fat tissue a person possesses estimated by bioelectrical impedance analysis
Time frame: Baseline, Week 8
Change in body fat percentage as measured by fat tissue relative to fat-free tissue
Relative amount of body fat a person possesses estimated by bioelectrical impedance analysis
Time frame: Baseline, Week 8
Change in cognitive function as measured by the Montreal Cognitive Assessment
Assessment of cognitive function where 0 is the lowest score and 30 is the highest score and a higher score represents higher cognitive function.
Time frame: Baseline, Week 8
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