Apparently healthy and well-functioning community dwelling 70-80 year-olds will be recruited to the study. All subjects undergo pre-screening for suitability and a physicians examination, as well as 7-day habitual daily steps are measured to ascertain baseline physical activity. Half of the recruited subjects (n=40) will be randomized into the intervention group and half (n=40) randomized into the control group. The intervention group is then required to reduce their daily steps to <2000 for a 2-week period. Thereafter, the intervention group participates to a 4-week strength+endurance training rehabilitation program and no longer has restricted daily step count. The control group continues their normal habitual physical activity level throughout the 6-week study period.

Inclusion Criteria:

1. aged 70-80 years,
2. community-dwelling,
3. able to walk 500 m without assistance or use of walking aid and regularly walking >5000 steps per day,
4. MMSE >24,
5. BMI 20-35 kg·m2 (i.e. not underweight or severely obese),
6. no serious cardiovascular or musculoskeletal disease,
7. no risk factors for deep-vein thrombosis (e.g. blood clotting disorder, obesity, bowel diseases, personal or family history of DVT etc.),
8. non-smoker,
9. provision of informed consent.

Exclusion Criteria:

1. Underlying diseases likely to limit lifespan and/or intervention safety. Contraindication for physical exercise or physical tests identified during physician's examination,
2. unwilling/unable to track daily step counts using accelerometer,
3. excessive and regular use of alcohol (more than 7 units per week for women and 14 for men)
4. difficulty in communication due to severe vision or hearing problems
5. unwilling to provide consent or accept randomization into either study group