We have previously shown that skeletal muscle has a memory of previous exercise training which we call "muscle memory". Muscle remembers exercise by storing chemical information in the muscle cells' DNA. This enables a greater effect of exercise when exercise is repeated at a later time.
The purpose of this study is to investigate whether skeletal muscle also remembers muscle wasting (i.e. atrophy). Also, to see whether exercise can protect the muscle from such a "negative" muscle memory.
The study protocol/intervention is 11 weeks in total with an option to undertake 7 weeks of additional training after the intervention is complete. This will involve:
- 14 days of unloading (one leg) by wearing a knee brace and crutches.
- 7 weeks of recovery either by either returning to normal habitual physical activity or by supervised resistance/weightlifting training (1 hour sessions, 3 days each week)
- Another 14 days of unloading of the same leg
- Another 7 weeks of active recovery where all participants will be provided with supervised resistance training to restore any muscle loss.
At each of the 4 timepoints described above (i.e. baseline → 14 days of muscle loss → 7 weeks of recovery → 14 days of muscle loss) we will take:
- Skeletal muscle biopsy to measure DNA methylation, gene expression, protein abundance, fibre type
- Muscle strength (using isokinetic dynamometry)
- Body composition (using DXA scan) and muscle architecture/structure (using ultrasound)
Who can participate:
- Both males and females
- Aged 18-40 yrs
- Healthy, no known diseases
- No regular exercise
Contact study leader
Advantages with participating
All participants will be offered structured strength training at NIH for the last 7 weeks of the project and with this training they will at least regain the muscle mass and strength they had at the start of the study.
With a normal response to the training, participants will be stronger when they finish the study compared to when they started, but if for some reason they have not returned to their pre-trial strength level in the last test, they will be offered further training until the strength is at least back to the starting point.
Participants will be involved in an exciting study where they will get a lot of information about themselves in terms of their physical shape and muscles that they would not otherwise gain insight into. Participation in the project will contribute to increased knowledge about the challenges many older people experience. Loss of muscle mass and gradual reduction in muscle function.
This knowledge of how muscle mass is regulated e.g. in repeated falls can help to develop good strategies to prevent rapid loss of muscle mass during immobilization and thus help to reduce the negative consequences of, among other things, femoral neck fractures in old age.