Many people remember periods of life based on the kind of workout that made them feel alive at the time. Yoga might have showed up for you in high school during peak stir-craziness with the whole “teenager” thing. Running may have wiped the slate clean when you felt overwhelmed in college. And maybe at-home strength training has been big for you in the last few months of quarantine. The truth is, it’s normal to get bored with workouts—no matter the phase of life. So we asked a brain expert why our preferred ways to sweat tend to evolve and change just as often as we do—and how to fall back in love with sweating again and again.

Cognitive neuroscientist Nan Wise, PhD, says that our movement preferences come in waves for the same reason we tire after eating too much of the same foods, or abandon a Netflix show mid-season: Our brains become habituated—or accustomed—to them and crave new, more exciting stimuli. “Habituation is that we basically tire or get used to an activity, reward, or reinforcement from experiencing it too often. There is no surprise; there’s no new information there,” says Dr. Nan.

When the human brain experiences a new kind of exercise (like, say, dance cardio), it begins to carve out new neuropathways (channels in the brain) to help you perform that choreography better and better. Your noggin’s main goal is to make you dance like Shakira instead of your dad at a wedding reception, but you may find yourself falling out of love with the rhythm as you dedicate more and more time to it. Why? Those neuropathways are well-trodden (or rather, well-danced), and because of this are no longer cognitively interesting to your brain.

In some ways, our constant longing to seek out new ways to sweat serves us. Research indicates that highly-varied workout routines (ones that involve more than one type of workout each week) are easier to stick with over time. On a physical level, too, regimens that include all four types of exercise (that’s aerobic, strength training, stretching, and balance exercises) set you up to avoid injury and work your body in all the ways that it desires. So really: You can consider that boredom a message from your body and mind that it’s time to add a little variety to the time you spend in your gym shorts.

Jessalynn Adam, MD, says there’s something else at play when you find yourself yawning during your spin session: You’re likely not setting clear goals to keep your brain and body entertained. In activities like yoga and running, there are built-in milestones. You learn a new pose; you cut time off your mile. Workouts like dancing or roller skating don’t often have such a clear progression—and that can make us grow tired of them. “Those mini-goals that you can set can certainly keep you interested. I think that’s part of the reason running never gets any easier, because as you get stronger and more conditioned, you can run farther and you can run faster,” says Dr. Adam.

That’s why, when you think about brainstorming the exercises that tick the previously mentioned exercise types, you should also think of a clear reason each one will serve you both physically and mentally. “Your motivation should be really small, incremental goals. And also, it should make you feel good,” says Dr. Adam. For example, you might think, ‘I’m learning to dance because I want to feel its happiness-boosting effects at least twice a week. Or, I’m going to take up Pilates because I want the Pilates burpee to be second nature to me.’

Dr. Adam also adds that competition can rekindle a workout that’s been falling flat for you lately. If you’re a runner seeking that high, sign up for a (far out) race. If you’re a swimmer, why not look into triathlons? And if you’re a yogi, consider moving outside of the bounds of your practice by signing up for an online workshop or working toward a pose you never thought you’d master.

Your love for certain workouts may ebb and flow like waves, but you can definitely learn to surf the many feelings that come and go. And that’s true whether you run miles, climb walls, or hop on a trampoline to get your heart racing.