Exercise dose: how much weekly activity, from minutes a week to daily steps

Church et al., the DREW trial (JAMA, 2007; PMID 17507344): peak oxygen consumption rose 4.2, 6.0 and 8.2 percent against control at about 72, 136 and 192 minutes a week, a graded trend. Duscha et al., STRRIDE (Chest, 2005; PMID 16236956), a separate group: at the same vigorous intensity the higher weekly amount raised peak VO2 more than the lower one. Vidoni et al. (PLoS One, 2015; PMID 26158265): fitness rose in a dose-dependent manner across 75, 150 and 225 minutes a week. Dalleck et al. (J Womens Health, 2009; PMID 19132882): 45 minutes a session raised VO2max about twice as much as 30. Ross et al. (Mayo Clin Proc, 2015; PMID 26455890): at a fixed low intensity, doubling the weekly amount halved the share of people whose fitness did not improve (38.5 to 17.6 percent). Against this, Reichkendler et al. (Obesity, 2014; PMID 24339390) found no extra fitness gain in young men from the larger dose, which is why the A is scoped to inactive adults of middle age or older. Instrument-measured VO2max, the dose-response replicated The same finding reproduced by a separate research group. A result seen once can be chance or bias; a replicated one is harder to explain away. by independent groups (Rule 06, the instrument-measured function route): A. The A is for the direction (more weekly exercise, more fitness gain), not for any one weekly number.

Slentz et al., STRRIDE (Arch Intern Med, 2004; PMID 14718319): weight and fat mass fell in a dose-response manner; the high amount lost 2.9 kg of weight and 4.8 kg of fat, the low amounts 0.6 to 0.9 kg and 2.0 to 2.5 kg, while controls gained. Three trials from other groups found no extra loss from the larger dose: Rosenkilde et al. (Am J Physiol Regul Integr Comp Physiol, 2012; PMID 22855277), 30 against 60 minutes a day for 13 weeks, fat loss 4.0 and 3.8 kg; Ross et al. (Ann Intern Med, 2015; PMID 25732273), waist and weight fell similarly at either amount; Reichkendler et al. (Obesity, 2014; PMID 24339390), body fat percentage fell similarly. Body weight and fat are measured markers, which cap a use at B, and the dose trials disagree: mixed results, C.

Kraus et al., STRRIDE (N Engl J Med, 2002; PMID 12421890): with weight held about steady, the high weekly amount improved 10 of 11 lipoprotein measures more than the lower amounts, and the improvement followed the amount of activity rather than its intensity. Dalleck et al. (J Womens Health, 2009; PMID 19132882) found HDL cholesterol rose across control, 30-minute and 45-minute groups in 26 women. Lipoprotein measures are markers, and HDL cholesterol in particular is not an established stand-in for heart events (see the LDL Low-density lipoprotein cholesterol, the cholesterol fraction most closely tied to plaque in the arteries. record, where raising HDL with drugs prevented nothing). One well-run trial on the main question, not repeated by another group: C.

Harris et al. (PLoS Med, 2019; PMID 31237875) followed the PACE-UP and PACE-Lift trials for 4 years in primary care records, masked to group: fewer new cardiovascular events (hazard ratio How often an event happened in the treated group compared with the control group over the same period. A ratio of 0.80 means 20 percent fewer events. 0.34, 95% CI 0.12 to 0.91; absolute reduction 1.6%, number needed to treat 61) and fewer fractures (hazard ratio 0.56, 0.35 to 0.90; absolute reduction 3.6%, number needed to treat 28); no difference in diabetes, depression or falls. Both trials came from one research group at St George's, University of London, these were follow-up outcomes rather than the trials' own primary outcome (step count), and fewer than 20 cardiovascular events occurred per group. A hard outcome, but one group's finding that no independent group has repeated: C. The plateau in daily steps seen around 6,000 to 10,000 a day comes from cohorts that only watched people and carries no letter (see this record's grade reading).

Stensvold et al., the Generation 100 trial (BMJ, 2020; PMID 33028588): five years of supervised training did not lower death from any cause against controls following activity guidelines, and 80% of participants already reported medium or high activity at the start. This is the only randomized trial in healthy older adults with death as its primary outcome. It tested more exercise on top of an active baseline, not exercise against inactivity. Tested on the stated endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score. and no benefit shown: D on Route 2 Human randomized trials have been run and did not show benefit on the stated outcome. One of the two routes to the lowest letter on EBL's scale. under the written definition. The link between more weekly activity and longer life comes from cohorts that only watched people and carries no letter under Rule 05.