560-610 minutes of exercise a week needed for substantial heart benefits

Original Article ↗ Hacker News Discussion ↗

New research cited in the thread suggests adults may need 560–610 minutes per week of moderate to vigorous physical activity — far above the familiar 150-minute guideline — to achieve a roughly 30% reduction in cardiovascular risk, versus about 8–9% at lower levels. Commenters debate how realistic this is for people with jobs, families, or limited resources, what actually counts as “moderate” or “vigorous” activity, and whether everyday movement, commuting, or chores should be included. Many also question the study’s observational design, older and relatively narrow participant group, and potential confounders, while agreeing that even smaller amounts of exercise still provide meaningful health benefits.

Required exercise time and benefits

  • New guideline (560–610 minutes/week of moderate–vigorous activity) is contrasted with prior ~150 minutes/week.
  • Study claims ~8–9% cardiovascular risk reduction at 150 minutes vs >30% at ~10 hours/week.
  • Some note other umbrella reviews suggesting much lower volumes (e.g., 15 MET-hours) already capture most benefits, making this result seem extreme.
  • Several emphasize that smaller amounts still help; “substantial” is a definitional choice.

Feasibility and life constraints

  • Many find 9–10 hours/week unrealistic, especially for parents in dual‑income households.
  • Others argue it’s possible by:
    • Integrating exercise with childcare (stroller runs, playing, hikes).
    • Active commuting (cycling/walking to work).
    • Small, consistent habits (e.g., 30 seconds of daily calisthenics with kids, then expanding).
  • Tension between “people make excuses” and recognition that time, job, kids, climate, and housing strongly constrain options.

What counts as “moderate” or “vigorous”

  • Confusion over definitions: brisk walking is classified as “moderate,” vigorous is framed as sustained higher heart‑rate zones, distinct from all‑out HIIT.
  • Debate on whether chores, normal walking, and weight lifting count; some wearables show everyday walking barely raises heart rate.
  • Clarifications from the thread:
    • Walking, housework, gardening often counted as moderate.
    • Vigorous minutes may be weighted more (e.g., 2×) in guidelines.
    • HIIT is described as beyond “vigorous” and not sustainable at high weekly volumes.

Health tradeoffs and human limits

  • Some argue 10 hours/week is too big a time cost relative to added lifespan; others highlight healthspan and enjoyment (e.g., sports people love).
  • Concerns about joint wear and injuries; countered by claims that the body evolved for regular movement and most people under‑exercise.
  • Skepticism about very high volumes, especially in older ages and with potential overtraining.

Study design, bias, and uncertainty

  • Study is observational; several criticize causal language and note correlation vs causation issues.
  • Participant profile: average age ~57, mostly white. Some see this as “late in life” and not broadly representative.
  • Potential confounders: people who exercise more may also eat better, avoid smoking, have more time and money, and care more about health.
  • Use of accelerometer data:
    • May miss activities with little wrist movement (cycling, some strength work).
    • Raises questions about how “moderate/vigorous” minutes were inferred.
  • Exclusion of very high VO2max values as “implausible” and undercounting of certain activities are flagged as possible flaws.
  • Overall sentiment: mixed—some find the results motivating or validating; others view the headline as overreaching or discouraging.