In a grand start to 2019, Hoka-sponsored athlete Jim Walmsley silenced many of his critics by qualifying for the 2020 U.S. Olympic Marathon Trials. What made his 1:04:00 Houston Half Marathon so incredible, however, is the fact that Walmsley is an ultrarunner. Among his accolades is a victory at the 2018 Western States 100, at which he also set a new course record. In fact, in post-race interviews from his race in Houston, Walmsley said he would be transitioning to higher mileage right away, in order to prepare for a 50-mile race the following month.

Going from an hour-long race to a half-day race is no easy feat. Neither is running a 50-mile race only a few weeks after a hard, fast half marathon. Will his mind and body recover that quickly? How will both be impacted by the minimal time between races?

It’s a common question for runners of all levels: How much time should I leave between hard efforts?

At the risk of sounding unhelpful, there isn’t a clear answer. The amount of time you should allow your body to recover after a race depends on three major things: your goals, your race experience and the races themselves.

Your Goals

Let’s say you just raced the Houston Half Marathon. You weren’t quite going Walmsley’s speed, but you certainly gave it your all. Your muscles will need time to recuperate from the race, especially if you had a long buildup and had been in training for months. Why? Because the high mileage and hard workouts take a toll on your body and your mind. If your goal is to see how fast your body can truly go and you’re racing half-marathon distances or longer, consider doing one race per season.

If your goal is to have fun or run the race at a moderate or easy pace, you have a lot more flexibility. Racing every month or even every few weeks is sustainable for a season (though I wouldn’t recommend doing that for longer than a few months, lest you experience burnout).

Your Race Experience

I’m not a proponent of revenge. But a “revenge race”? There’s some legitimacy to the concept. If you have a negative race experience—maybe you fell, or the weather was bad, or you didn’t finish—it can be very beneficial to proverbially “get back on the horse” and enter another race.

On the other hand, if you had a wonderful race experience, it’s equally important to take a step back. Reflect on your success, enjoy it and let your body recover.

Race Day

If you’re racing a half marathon or longer, your body will be a lot more beat up afterwards than it would be if you’d raced a 5K—particularly because the training for a half marathon is much more intensive than that of a 5K. For that reason, racing a 5K the weekend after racing another 5K is not too bad. Racing two marathons back-to-back, however, is much more likely to result in decreased performance or injury.

If you just crossed the finish line of a marathon and are already itching to race again, try doing a 5K or 10K instead. The decreased distance will provide mental relief from the pressure to perform, and it will be less of a strain on your recovering muscles.

While there isn’t an iron-clad standard for doing back-to-back races, there is a helpful principle that I live by: Only race when your body and your mind are up to it. Yes, there are days when running isn’t as fun. But there should never be a day when you’re hurting yourself to accomplish that next race or that new personal record. Good performance comes from a place of joy, not exhaustion.