A Comparison of Neuromuscular Recruitment in Trained and Untrained Adults
Mayo Clinic
Summary
The objective of the study is to use neurological techniques to obtain quantitative measurements of nervous system control of skeletal muscle activity in adults aged 60-85 who are either long-term resistance exercisers or who are untrained.
Description
We propose to perform a cross-sectional study in 20-40 highly resistance-trained people and compare with 20-40 untrained people matched for age, sex, and BMI. in adults. Participant will complete 5 study visits. In the first visit, participants will complete a screening visit in which blood will be taken to rule out inclusion and exclusion criteria. Participants will also have their body composition measured by DEXA, Meal tolerance testing, a VO2max test on a cycle ergometer, and a muscle strength test using a knee extension machine, handgrip dynamometer and muscle motion testing. A second a…
Eligibility
- Age range
- 60–85 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria * Participant must have a BMI between 18.5 and 38 * Participant be aged between 60 and 85 * Regularly exercises at least 5 days a week a minimum of 30 minutes per day. * Engages in less than 2 days of exercise less than 30 minutes each day. * Participant must use the Mayo Clinic patient online portal. * Participant must be able to understand English without the need of an interpreter. * Must be willing to be contacted for research * Participant must be willing and capable to provide consent. * Participants shall be generally healthy as deemed acceptable by the principal inv…
Interventions
- Diagnostic TestNeuromuscular Test
To measure neuromuscular connectivity, Transcranial Magnetic Stimulation (TMS) will be used to stimulate regions of the cerebral cortex known to control specific muscles. Electromyography (EMG) activity will then be measured from the following muscle groups: deltoid, biceps, extensor digitorum communis, abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscle.
- Diagnostic TestDEXA
The DEXA test uses X-rays to measure how many grams of calcium and other bone minerals are packed into a segment of bone. The test also measures the amount of fat-free mass, and fat mass.
- Diagnostic TestMixed Meal Tolerance Test
Fasting blood will be collected for glucose, insulin, and c-peptide. Participants will be provided with a milkshake with a fixed amount of protein, carbohydrates, and fat. Glucose, insulin, and c-peptide will be measured at multiple time points (every 10 minutes) until four hours after consumption (50% Fat, 30% Carbohydrate HO, 20% Protein). Approximately 70mls of blood will be drawn during this time
- Diagnostic TestStrength Test
Knee extensor strength will be tested by gradually increasing the workload on a pneumatic Keiser knee extension machine. The test will begin with a warm-up of 4-5 reps with one leg at 30-50 psi. Then the participant will increase the workload at self-selected intervals ranging from 5-20psi until a maximum effort is achieved. If a rep is failed, then the workload will be reduced by 5psi until a successful rep is performed or a workload is reached in which a successful rep had been previously achieved. Handgrip strength will be tested using a handheld dynamometer (Baseline® standard hydraulic hand dynamometer). The test is performed with the participant seated with the elbow unsupported and flexed at 90 degrees, forearm neutral, wrist held between 0-15 degrees of ulnar deviation (Horowitz, 1997). Maximum grip is the average of three 3-5 second trials.
Location
- Mayo ClinicRochester, Minnesota