How Much Exercise Do You Need to Lower Diabetes Risk? Understanding MET Values

“Exercise more” is common advice, but it rarely comes with a number attached. Diabetes prevention research actually has one, expressed through a measure called MET — the Metabolic Equivalent of Task — which quantifies exactly how much a given activity, and how much of it, translates into reduced risk.

What a MET value actually measures

One MET represents the energy your body uses at rest. Every activity above that gets a multiple: a MET value of 3 means an activity uses roughly three times the energy you’d burn sitting still. It’s a standardised way to compare wildly different activities on the same scale:

The scale runs from passive (watching TV, at 1 MET) up to vigorous, sustained effort (fast running, at 10 METs) — and everyday activities like brisk walking and slower cycling sit in a moderate middle band that turns out to matter a great deal for diabetes prevention.

Turning MET values into a weekly total

MET values become useful for prevention purposes once you multiply them by time: MET-hours per week (MET-h/week) is the activity’s MET value multiplied by the hours spent doing it. A dose-response meta-analysis of prospective cohort studies, published in Diabetologia (2016), tracked how relative risk of type 2 diabetes changed as leisure-time physical activity (measured in MET-h/week) increased. The relationship was clear and graded: relative risk started at the baseline of 1.0 with no activity, and declined steadily as MET-h/week rose, reaching roughly 0.4 — a 60% reduction — at 60 or more MET-h/week.

The most practically useful figure from this research is a specific, achievable benchmark: brisk walking for about 6 hours a week works out to roughly 15 MET-h/week (walking’s MET value of roughly 3, multiplied by 6 hours, landing in that range once weekly totals are considered), and that level of activity alone was associated with over a 30% reduction in diabetes risk.

Why this figure matters

Six hours a week of brisk walking sounds substantial written out as a weekly total, but broken down it’s under an hour a day — a genuinely achievable amount for most people, using one of the lowest-intensity activities on the MET table, not a demanding gym regimen. The research doesn’t suggest you need to reach fast-running or high-intensity aerobics levels (MET values of 7-10) to see a meaningful risk reduction; a much more moderate, sustainable activity gets you a substantial share of the benefit.

That said, the dose-response curve keeps declining well past 15 MET-h/week, continuing down to roughly 0.4 relative risk by 60 MET-h/week — so more activity continues to add benefit for those able to do more, rather than the effect capping out after the initial 30% reduction.

Building your own weekly total

Since MET-h/week is simply MET value multiplied by hours, it’s straightforward to combine different activities to reach a target. Someone might combine three hours of average-pace walking (roughly 9 MET-h) with one hour of cycling at a moderate pace, or substitute higher-intensity but shorter sessions — a single hour of weights training (MET value 8) contributes as much as roughly 2.5 hours of walking. The table above is essentially a menu: what matters for this research is the weekly MET-hour total, not necessarily the specific activity used to reach it.

Frequently asked questions

Do I need intense exercise to lower my diabetes risk? Not necessarily. The specific benchmark cited in this research — brisk walking roughly 6 hours a week, equivalent to about 15 MET-h/week — was associated with over a 30% risk reduction, using one of the lower-intensity activities on the MET scale rather than vigorous exercise.

Does more exercise keep helping past that point? Yes, based on this dose-response data. Relative risk continued declining beyond 15 MET-h/week, reaching roughly 0.4 (a 60% reduction) at 60 or more MET-h/week — so additional activity continued to add benefit rather than plateauing early.

How do I calculate my own weekly MET-hours? Multiply an activity’s MET value by the hours spent doing it each week, then add up across all activities. For example, three hours of average walking (MET value 3) contributes 9 MET-h/week; add a one-hour jog (MET value 7) and the weekly total becomes 16 MET-h/week.

This article is for general information only and does not constitute medical advice. If you have a diagnosed diabetic condition or any health concerns, consult your doctor before starting a new exercise programme.