Sarcopenia
Conditions
Keywords
sarcopenia, muscle, protein, muscle protein synthesis, muscle protein breakdown, whey, soy, casein, dose response, resistance exercise, unilateral, knee extension, whole body protein
Brief summary
When we age, we lose muscle. It is not exactly clear why this happens, but we do know that this muscle loss can increase health risks and lead to health problems. Lifting weights (i.e. performing resistance exercise) and proper nutrition, in particular eating enough high quality protein, can help slow the loss of muscle mass or potentially even reverse it. Protein and resistance exercise are thought to do this by stimulating your muscle to make more proteins and/or potentially by slowing down the rate at which your body breaks proteins down. Whey protein is a high quality protein isolated from milk and is known to stimulate new protein synthesis for all proteins in your body. However, to date, the effect that whey protein has on muscle protein synthesis, particularly in the elderly has yet to be determined. Thus the purposes of this study are: 1) to determine if whey is an effective source of protein that will stimulate muscle protein synthesis in the elderly, similar to what we have previously seen in young persons; 2) to determine the smallest amount of whey protein to consume to maximally stimulate your muscle to make new proteins; 3) to see if performing resistance exercise will augment the increase in new muscle protein synthesis with whey consumption; and 4) to try and found out if whey is more effective than soy protein in stimulating new muscle protein synthesis and suppressing muscle protein breakdown in the elderly, similar to what we have previously seen in young persons
Interventions
Whey and casein are isolated milk proteins
Sponsors
Study design
Eligibility
Inclusion criteria
* Male * Aged 60 to 80 years old * Non-smoker * Generally healthy and can tolerate the resistance exercise and protein drink
Exclusion criteria
* Allergies to whey, casein or soy * Health problems such as: heart disease, rheumatoid arthritis of the knee joint, diabetes, poor lung function, uncontrolled hypertension, or any health conditions that might put participants at risks for this study * Failed clearance for exercise participation by their medical doctor * Failed an exercise stress test * Taking metformin and/or other medications for the control of blood glucose even though one might not be classified as diabetic * Taking prescribed blood thinners such as warfarin and heparin but excluding aspirin * Taking medications for lung and kidney conditions but excluding medication for asthma that is under control
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Muscle protein synthesis | Acute within the day |
| whole body amino acid oxidation | acute within the day |
Secondary
| Measure | Time frame |
|---|---|
| muscle protein breakdown | Acute within the day |
| serum insulin | acute within the day |
| plasma amino acid concentrations | acute within the day |
Countries
Canada