When you’re leveling up in training, that should come with a little extra fatigue, but it shouldn’t be the new normal. Some fatigue is normal and a healthy part of tough training. We want the majority of our miles to feel really easy, and if you just can’t seem to find easy, it’s best to take a step back so you can come back fresh.

The point of training is not to teach the body to slog or to develop fatigue resistance (basically, getting really good at eeking out low-quality workouts when you’re tired). Working harder to make less happen is not a training adaptation that we’re aiming for.

We’ve all had a day where you have to work extra hard just to make a normal run happen, but those days would probably best be spent with your feet up on the couch. If you feel like getting to your usual cruising pace is taking a monumental effort, that could be a sign that you should do a recovery ride, walk or just take the day off. Make sure any HR data you’re using is coming from a reliable source and NOT a wrist-based sensor.

Though it may not feel scientific, perceived exertion or effort is one of the most accurate ways to evaluate your effort. Heart Rate Doesn’t Match Perceived Exertion It’s better to miss one run that to come back the next day even deeper in a fatigue hole after just going through the motions. If you can rally and put together 15 minutes, great! If you can’t get your head into it, and 15 minutes in still feels like an eternity, turn around and head back home. On those days, barring any outside explanation (work stress, lack of sleep or the like), give yourself the chance to get out for 15 minutes. Sometimes, you just might not be feeling it. You can’t channel your inner Chris Traeger every day. Motivation will ebb and flow, and that’s totally okay and normal in an athletic life. With those caveats in mind, here’s what to think about if you might need a bonus rest day. Packing too much mileage into too few days of running can also raise your risk of injury, and is less helpful for stimulating training adaptations. That’s why we always recommend a shakeout the day before a race.

Taking a day off can negatively impact blood volume, which leads to fatigue (though it’s negligible with one day off). The key components of success are frequency and consistency. Rest can be a bit of a magic bullet for lots of issues, but it can also have diminishing returns if you rest too much, or don’t address underlying problems related to fatigue. But, a gradual decline in run quality, and lingering fatigue, isn’t okay. Big picture, a couple of tough runs a week is okay and can usually be course-corrected through rest, a little extra sleep and maybe a dietary tweak. It can be tough to tell if you’re headed towards overtraining because by the time that it’s obvious, it’s way too late. While we recommend most athletes take one or two days off a week, that magic number can vary with other life factors like stress, sleep, nutrition and fatigue. Rest days are your first line of defense against injury, burnout, and worse – OTS. If you’re typically a motivated athlete (motivated enough, say, to hire a coach and read articles to help you improve your training) and you’re asking yourself this question, that could be a good sign that you might need a little time off.

Microcosm vs mood