At some point, everyone misses a workout (or two). It isn’t a matter of if — but when. From injury to illness to vacation and work stress, there are plenty of reasons you might miss a workout. But how many workouts can you skip before you start losing your hard-earned gains?

Beyond One Week

Missing a workout isn’t necessarily a bad thing. In fact, taking as much as a one week off from training can sometimes be a smart strategy that can help you gain more strength or develop greater aerobic fitness in the long run.

For example, if you’re following a marathon training program, your coach may have you back off for a week to give your body a longer time to recover and rebuild from all the intense training sessions. Instead of seeing your performance decline, you might even see it improve when you get back to your routine, especially if you were pushing yourself too hard and not fueling properly.

However, once you start creeping past the one-week mark, you may start noticing some decreases in strength and fitness.

Two to Four Weeks Out

If you’re following an aerobic training program, you may experience declines in endurance within just two weeks of stopping your workouts, though those declines may not be obvious at first within four weeks, however, the changes may be more noticeable. A recent study of recreational marathon runners reveals four weeks of detraining led to a 3.6% decline in blood volume, along with a significant reduction in left ventricle mass.

Similarly, research on elite rugby and football players found they could maintain muscular strength for up to three weeks. A study on non-athletes found similar results.

Why consistency matters

However, how quickly you lose progress depends on your training history. If you’re new to exercise and you take a few weeks off, you’ll likely lose more progress than someone who’s been training consistently for 3–4 years.

Consistency is important. If you’re consistent with your exercise program, taking a week off here and there isn’t a big deal. But if you fall into a pattern of exercising for a few weeks and then take a week or two off, you are likely to lose progress every time you stop your routine.

If you have a week coming up you know is going to be especially stressful, consider scaling back instead of trying to adhere to your usual routine or skipping the week altogether. Honestly, even getting a couple of workouts in that week might be enough to maintain whatever you were doing before, and lowering your expectations will reduce the workout ‘burden’ . You can get back into your routine the next week.”

When your goal is fat loss

If you’re exercising for fat loss and you suddenly pause your routine, whether or not you continue making progress largely depends on how you handle your diet. After all, exercise helps create a caloric deficit, so it’s important to manipulate your diet to account for the calories you would have burned. If you keep eating the same amount of calories, “there’s a good chance some of that weight is going to be put back on.

If you do regain weight, how much and how quickly it appears depends on how much you’re eating, as well as other lifestyle factors, like sleep, stress and physical activity. But, in general, you might notice weight regain as soon as two or three weeks.To protect against weight regain, be sure to adjust your caloric intake to account for the calories you’re not burning through exercise.

The bottom line

There are many reasons you might have to take time off from exercise. Maybe you’re going on vacation for a week and you’d rather not worry about exercising while you’re away. Or, maybe life is unusually stressful right now. Whatever your reason, the key to not losing progress is to get back into your routine as soon as you can. Don’t keep saying, ‘I’ll get back to it tomorrow, what’s wrong with today?

The exception: If you’re sick or injured, take your time getting back into your exercise routine. Work with a medical and/or fitness professional if needed.

Zoë