Table 3.
A summary of intervention studies examining the effects of reduced physical activity with countermeasures to reduce metabolic and musculoskeletal effects. The table outlines the participant cohorts (including age, BMI), details of the inactivity intervention and countermeasure used, along with key results.
| Reference | Participants | Inactivity | Countermeasure | Main findings |
|---|---|---|---|---|
| Moore et al.71
14 days SR + RT |
14 male older adults (71 year, 25% body fat) >3500 step/day |
Activity by SenseWear. Steps/day ↓: BL 7011, SR <1500 |
SR only versus SR+EX: 6 sessions of unilateral low-load, high-effort resistance exercise (i.e. three sessions/week with at least 48 h between sessions) with a randomly selected leg |
RT associated with greater muscle fibre CSA, satellite content and capillarization. |
| Devries et al.57* 14 days SR + RT ± nutritional supplement |
30 older men (70 years, 27 BMI) >3500 step/day 3 groups (1) whey isolate, (2) micellar-whey, (3) micellar-whey + citrulline (n = 10 each group) |
Activity by SenseWear. Steps/day ↓: BL 6273–7714, SR 1161–1288 |
Dietary intervention during SR. Throughout SR, participants performed 6 sessions of unilateral low-load, high-effort resistance exercise (3 sessions/week with at least 48 h between sessions) with a randomly selected leg |
MPS similar across groups so dietary groups were collapsed to
compare SR and SR+RT legs. MPS lower in SR than SR+RT in postabsorptive and postprandial states. |
| Walhin et al.27* 7 days SR + overfeeding ± aerobic exercise |
26 young males (25 year, 24 BMI) |
Activity by Actiheart. BL highly active >30 min 3× week, Steps/day ↓ with ↑ dietary intake +50% (SUR); additional subgroup with exercise (SUR+EX). SUR: 12,562–3520 and SUR+EX 10,544–3690 step/day |
SUR (n = 14) versus SUR+EX (n = 12): 45 min of daily treadmill running at 70% of maximum oxygen uptake |
Vigorous-intensity exercise counteracted most effects of short-term overfeeding and under-activity at whole-body level and in adipose tissue, despite standardized energy surplus |
| Perkin et al.48
14 days SR + exercise |
30 older men (aged 65–80 years) |
Activity by pedometer. Steps/day ↓: BL >3500, SR <1500 |
SR only (n = 10)
versus Progressive RT group (n = 10) versus ‘Exercise snacking’ home-based group (n = 10) |
Not yet reported |
BL, baseline; BMI, body mass index; CSA, cross-sectional area; EX, exercise; h, hour; MPS, muscle protein synthesis; RT, resistance training; SR, step reduction; SUR, energy surplus; * studies also listed in Tables 1 and 2 but described in a different context; ↑ significant increase; ↓ significant decrease.