Muscle Hypertrophy Clinical Trial
Official title:
Muscle Fibre Activation is Unaffected by Load and Repetition Duration When Resistance Exercise is Performed to Task Failure
How much weight an individual lifts per workout does not dictate the relative increase in muscle size the individual gains following weeks of training, which is contrary to current strength training dogma. Specifically, researchers have concluded that so long as an individual performs resistance exercise with maximum effort, it is not necessary to lift with relatively heavy loads. However, other laboratories, on the basis of surface electromyography measurements, have challenged the thesis that lighter loads can result in the hypertrophy of larger, type II muscle fibres. Therefore, the purpose of this study was to combine surface electromyography measurements with direct measurements of muscle fibre activation to see if muscle fibre activation was truly dependent on load. The investigators hypothesized that all muscle fibres would be activated when the resistance exercise was performed with maximal effort.
PROCEDURES INVOLVED IN THE RESEARCH
The total time commitment of this study will be ~7 hours. Each participant's first visit
(familiarization) will include an interview through where the researchers will determine if
there are any reasons that the participant cannot take part in the study. The researchers
will explain the study protocol and, upon the participant's consent, the investigators will
obtain the participant's knee extension maximum voluntary contraction (MVC) on a dynamometer
(Biodex, Shirley, USA) and a 1 repetition-maximum (RM) test on a knee extension machine.
Following that, the investigators will determine the next two dates (trial days) in which the
participant will come in.
The participant will be asked to come in fasted on two separate trial days, each separated by
two weeks, after the participant's familiarization visit. The participant will be required to
avoid physical activity 48 hours before each of the three visits. There are four conditions
in this study, each varying in relative load and speed of contraction. The participant will
complete two conditions on each trial day, one with each leg. The conditions include: 80%RM
Normal (80N; 1 eccentric: 1 pause: 1 concentric), 80% Slow (80S; 3:1:3), 30% Normal (30N;
1:1:1) and 30% Slow (30S; 3:1:3). Each condition will include three sets to voluntary failure
on a knee extension machine. Before and after each set the participant will perform three
MVCs on the dynamometer identical to what the participant did on the familiarization day. The
investigators will record the participant's rating of perceived exertion and effort via the
Borg scale and electromyography (EMG), respectively. The participant will have one biopsy
taken pre-training and two, one per condition/leg, one hour post-training.
The REB Project Number for this study is: 802
;
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT04000750 -
Time-Restricted Eating and Muscle Hypertrophy
|
N/A | |
| Completed |
NCT03993483 -
Upper Versus Lower Limb Responses to Higher Versus Lower Load Resistance Training in Young Men
|
N/A |