Evidenced Health

Physical Activity and Fitness Hub

3 min read

Navigator for the aerobic-activity and fitness clusters — how much movement and fitness move mortality, whether raising them helps, and whether the energy spent on exercise is offset by compensation. The strength, resistance-training, muscle, and falls side moved to Musculoskeletal Health and Physical Function Hub. Nucleus: Cardiorespiratory Fitness and Mortality.

Aerobic activity and sedentary time — dose and mortality

  • Physical Activity Dose and Mortality — the objective-measured dose-response (accelerometry removes the self-report plateau; the steepest gains are at the least-active end), the step-count targets (age-varying plateau ~6-8k older / 8-10k younger), and whether ~60-75 min/day of activity offsets the mortality risk of prolonged sitting (it does)
  • Sedentary Behaviour and Chronic Disease Risk — the dedicated sedentary anchor (Patterson 2018 gold dose-response MA): total sitting vs TV viewing as two exposures, per-outcome accelerating-harm knees (~8h sitting / ~3.5h TV for all-cause; PA-adjusted), and incident T2D — TV->T2D the strongest association (1.09/h, 29% PAF), most caveated by reverse causation and dietary mediation
  • Wearable Activity Trackers and Physical Activity — the adherence/behaviour-change lever for reaching the dose (not a new dose fact): a consumer tracker adds ~627 steps/day (95% CI 417-862, I2=3%, GRADE low) short-term, but durability is unproven (the 2 trials >=12mo showed lower adherence) and the outcome is a surrogate; ranks as a small adherence aid, best paired with human contact, most useful for the near-inactive (Brickwood 2019 MA, 28 RCTs)
  • The Physical Activity Paradox — the domain caveat on the dose page: high occupational (work) PA associates with higher mortality in men (Coenen, HR 1.18), opposite to leisure/total PA — so physically demanding work does not substitute for leisure exercise on the mortality outcome (LOW confidence; observational, healthy-worker selection; opens the occupation cluster)
  • Night Shift Work and Breast Cancer — the occupation cluster’s circadian channel, and a well-powered NULL: pooled across 10 prospective studies (1.4M women) night shift work shows no meaningful effect on breast cancer (RR 0.99, 0.95-1.03), overturning a case-control-driven prior and the IARC 2A probable carcinogen reading (MEDIUM confidence; a symmetric-standards counterweight)

Cardiorespiratory fitness — marker and lever

The economics of exertion

  • Exercise Energy Compensation — whether exercise expenditure is offset by reduced non-exercise activity or increased intake, and whether higher intensity worsens the offset
  • Exercise vs Caloric Restriction for Visceral Fat — at a matched weekly energy deficit, exercise reduces visceral fat more than diet (dose-dependent; diet’s slope flat) — the exercise-vs-diet lever for the metabolically-active depot

Physical activity and chronic kidney disease

  • Chronic Kidney Disease and Modifiable Exposures — PA is the WEAKEST of the three CKD-prevention levers (Seidu MA: most-vs-least-active RR 0.91, GRADE very-low, all 12 cohorts serious ROB, 95% prediction interval 0.75-1.09 crosses 1); healthy-user self-selection + reverse causation uncorrected, and PA’s mechanism routes largely through the obesity/glycaemia/BP channels. See the nucleus for the full 3-lever ranking

Graph View