Metabolic Disease
Conditions
Keywords
exercise, muscle, metabolism, circadian
Brief summary
The aim of the current study is to determine the effect of time of day on the muscle and metabolic responses to resistance exercises in obese or overweight adults. To achieve this aim we have the following objectives: 1. Compare the effects of resistance exercise training performed in the morning vs the evening on insulin sensitivity 2. Compare the effects of resistance exercise training performed in the morning vs the evening on gains in muscle mass and strength 3. Compare the acute glucose responses to resistance exercise performed in the morning vs the evening
Interventions
Exercise will consist of 1 set x 9 exercises x 3 sessions per week x 6 weeks. The load to be used during training will be calculated as 80% of one-repetition maximum (1RM) with each set performed to failure. 1RM will be re-tested on week 3, and the load adjusted accordingly, and upon completion of the study. During the training period, all sessions of training will be supervised by the researcher. The following exercises will be performed: Bench press, biceps curl, lat pull down, overhead press, lateral raise, leg extension, leg curl and calf raise.
Sponsors
Study design
Eligibility
Inclusion criteria
* pass the physical activity readiness questionnaire * body mass index (BMI) \>27kg/m² and limited to 40 kg/m².
Exclusion criteria
* Prior surgery for weight loss * Prior history of heart, lung, cancer, endocrine or liver disease * Participating in more than 1 hour structured exercise training per week
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in insulin sensitivity | Change from baseline to 6 weeks | Insulin sensitivity calculated via the Matsuda Index during an oral glucose tolerance test |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in whole body lean mass | Change from baseline to 6 weeks | whole body lean mass measured via bio-electrical impedance |
| Change in whole body fat mass | Change from baseline to 6 weeks | whole body fat mass measured via bio-electrical impedance |
| Change in one-repetition maximum muscle strength | Change from baseline to 6 weeks | Sum of one-repetition maximum of Bench press, biceps curl, lat pull down, overhead press, lateral raise, leg extension, leg curl and calf raise exercise |
| Change in vastus lateralis muscle thickness | Change from baseline to 6 weeks | Muscle thickness of the vastus lateralis muscle measured via ultrasound |
| Change in grip strength | Change from baseline to 6 weeks | Grip strength measured with a hand held dynamometer |
| Change in mean glucose levels | Change from baseline to 6 weeks | Mean glucose levels measured via continuous glucose monitors |
| Change in glucose variability | Change from baseline to 6 weeks | Glucose variability measured via continuous glucose monitors |
| Change in knee extensor maximal isometric torque | Change from baseline to 6 weeks | Knee extensor maximal isometric torque measured during a maximal voluntary contraction |
Countries
United Kingdom