The purpose of this study is to evaluate the acute local skeletal muscle inflammatory response to thigh muscle (quadriceps) eccentric muscle actions. Eccentric muscle actions occur when the muscle is lengthening as it contracts. This is a pilot project to assess the degree of inflammatory biomarkers, called myokines, that are released locally in skeletal muscle tissue after an acute bout of resistance-exercise using a resistance-exercise machine called an isokinetic dynamometer.
The intervention will involve one session of maximal eccentric exercise of the knee extensor muscles (quadriceps) of the right leg. During the 24-hour period preceding the intervention, participants will be asked to refrain from any for of moderate-vigorous physical activity or exercise. Participants will perform 30 sets of 10 repetitions of maximal isokinetic eccentric knee extensions at 60 degrees/second with 1-minute of rest between each set. Before completing the exercise bout, each participant will be asked to remain in a seated position (resting) for 30-minutes and then provide a skeletal muscle biopsy using the modified Bergstrom with suction muscle biopsy technique from the vastus lateralis on the right leg. This will be done for the baseline assessment of 5 myokines including apelin, fibroblast growth factor-21, irisin, interleukin-6, and interleukin-15. Then the participants will complete the exercise bout as described above. They will then rest quietly in the laboratory for 3-hours and wait for the second skeletal muscle biopsy to be taken following this 3-hour wait.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
12
Each participant will complete 300 repetitions of eccentric knee extensions using an isokinetic dynamometer after a baseline skeletal muscle biopsy is taken. Three hours following this, a second muscle biopsy will be taken to evaluate the changes in the dependent variables being measured (myokines).
Applied Research Centre, Faculty of Kinesiology, University of Manitoba
Winnipeg, Manitoba, Canada
RECRUITINGApelin
Concentration of apelin in skeletal muscle tissue
Time frame: Baseline and 3-hours post-exercise
Fibroblast growth factor-21
Concentration of fibroblast growth factor-21 in skeletal muscle tissue
Time frame: Baseline and 3-hours post-exercise
Irisin
Concentration of irisin in skeletal muscle tissue
Time frame: Baseline and 3-hours post-exercise
Interleukin-6
Concentration of interleukin-6 in skeletal muscle tissue
Time frame: Baseline and 3-hours post-exercise
Interleukin-15
Concentration of interleukin-15 in skeletal muscle tissue
Time frame: Baseline and 3-hours post-exercise
Body mass
Body mass in kilograms
Time frame: Baseline
Body height
Body height in meters
Time frame: Baseline
Body mass index
Body mass index in kg/m\^2
Time frame: Baseline
Fat mass
Fat mass in kilograms
Time frame: Baseline
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Fat free mass
Fat free mass in kilograms
Time frame: Baseline