How many METs should today's workout be when your recovery score is low?
A MET compares an activity's energy cost with sitting quietly. On low-recovery days, favour light work under 3 METs and keep vigorous efforts for fresh days.
On a day when your recovery score is clearly below your usual range, a sensible target is mostly light activity under 3 METs, with perhaps a short stretch of moderate work between 3 and 6 METs, and nothing in the vigorous band of 6 METs or more. Those bands come straight from the way the metabolic equivalent of task is commonly used to grade activities: under 3 METs is light, 3 to 6 is moderate, and 6 or more is vigorous. The rest of this guide explains what a MET actually measures, why the number is useful for choosing today's effort, and where it stops being precise enough to trust.
What is a MET, in plain terms?
A MET expresses how much energy an activity costs relative to body mass, compared with a reference value for sitting quietly. By convention that reference is set at 3.5 millilitres of oxygen per kilogram of body mass per minute. In energy terms, one MET is also written as 1 kilocalorie per kilogram per hour.
So when an activity is listed at 4 METs, the idea is that it costs roughly four times the energy of sitting still. That makes the scale easy to read without a lab. You do not need to know your oxygen uptake to understand that a 10-MET effort is a very different day from a 2-MET walk. It is a ratio, and ratios are good for comparing one choice against another.
Which everyday activities land in each band?
Seeing real examples helps more than the definition. Writing, desk work and using a computer sit at about 1.5 METs, and walking slowly is listed at 2.0. Walking at 3.0 mph (4.8 km/h) reaches 3.0 METs, and sweeping, mopping or vacuuming falls between 3 and 3.5. A yoga session with postures and breathing work is listed at 3.3, while moderate weight lifting and doubles tennis are both given 5.0.
The vigorous band starts quickly once you add speed. Light-effort cycling on the flat at 10 to 12 mph is listed at 6.0 METs, jogging at 5.6 mph (9.0 km/h) at 8.8, and running at 8.1 mph (13.0 km/h) at 12.9. Football (soccer) is listed at 10.3 and rowing at 10 mph at 16.4. One detail worth remembering is that vigorous household chores can add up to as much energy expenditure as dedicated exercise. If you spent the morning moving furniture, that counts.
How do MET-minutes add up over a day or week?
METs become more useful when you multiply them by time. A 4-MET activity done for 30 minutes gives 120 MET-minutes, or 2.0 MET-hours, and an 8-MET activity for only 15 minutes gives the same 120 MET-minutes. In other words, a short hard session and a longer easy one can carry a similar total energy cost.
That simple arithmetic is the heart of using METs on a recovery day. If your plan called for a 30-minute hard run, you can keep some of the movement by swapping it for a longer walk at a far lower intensity. The total dose shrinks a little, but the intensity, which is what tends to tax a poorly recovered body most, drops a lot. On a good day you can do the opposite and pack more work into less time.
Population research uses the same idea at a larger scale. One meta-analysis linked an increase of 11.25 MET-hours per week in physical activity with a 23 percent lower risk of cardiovascular death and a 26 percent lower risk of type 2 diabetes. Those are associations across large groups, not a promise for any one person, but they show why weekly totals matter more than any single heroic day.
Where do published MET values come from?
Most MET tables trace back to the Compendium of Physical Activities. It was developed for epidemiological studies so that researchers would assign the same intensity to the same activity in questionnaires. Dr. Bill Haskell of Stanford University conceptualised it, it was first used in a study run from 1987 to 1989, and it was published in 1993 with updates in 2000, 2011 and 2024. The 2024 update added an Older Adult Compendium and an updated Wheelchair Compendium.
Knowing that origin helps you read the numbers correctly. They were built to compare activities in surveys of many people, which is why they work well for ranking options and less well for predicting exactly what your own body will burn.
Why is a MET only an estimate for you personally?
The 3.5 mL/kg/min reference was first derived from the resting oxygen consumption of one particular subject, a healthy 40-year-old man weighing 70 kg. Resting metabolic rate depends mainly on lean body mass rather than total weight, so the one-MET rule of thumb can vary substantially from person to person. Calorimetry studies have found that the conventional value overestimates resting oxygen use by about 20 to 30 percent on average, with body composition explaining most of the difference.
The practical takeaway is simple. Treat calorie numbers built on METs as rough estimates, not as a precise budget. The ranking, though, holds up well: running is harder than walking for almost everyone, and that is the part you need when deciding how hard to go today.
Using METs together with your recovery score
Your recovery score reads how settled your body is this morning, drawing on overnight heart rate, heart rate variability and sleep. METs describe how demanding a planned activity is. Put together, they give you a simple decision rule: match the size of the demand to the size of the reserve.
When your score is in its usual range, the full menu is open, including vigorous work above 6 METs such as runs, hard rides or intervals. When it is a little low, keep the activity but move it down a band, for example turning a run into a brisk walk or a hard ride into an easy spin. When it is clearly low for several days, stay mostly in the light band and add rest.
This matters because a persistently high resting heart rate after adequate rest, such as in the morning after sleep, and reduced heart rate variability are both listed among possible signs of overtraining. Overtraining is described as exceeding the body's ability to recover from strenuous exercise, and people who reach it stop making progress and can even lose strength and fitness. A low score is not a diagnosis, but it is a good reason to choose a lower MET band for the day.
A sample low-recovery day by the numbers
Imagine your plan says 40 minutes of running at about 8.8 METs. That is roughly 350 MET-minutes of fairly intense work. On a low-recovery morning you might instead walk slowly for 20 minutes at 2.0 METs and then briskly for 30 minutes at 3.0 METs. The total comes to about 130 MET-minutes, all of it in the light-to-moderate range.
You have still moved for close to an hour, your legs and heart have done some work, and you have avoided the vigorous band that would ask the most of a tired system. Tomorrow, if your score rebounds, the run is still there. If it does not, you have lost very little by being patient.
A note on safety
MET values describe typical demands for healthy adults, and individual responses differ. If you have a heart, lung or metabolic condition, are returning from illness or injury, or are pregnant, talk with a doctor before using these bands to plan harder sessions. Stop and seek help if exercise brings chest pain, unusual breathlessness or dizziness. Your recovery score and MET tables are general guides for choosing today's effort, not medical advice.
This article is general health information and is not a substitute for medical diagnosis or treatment. Consult a healthcare professional if you have concerns.