You’re visiting your friend’s house and he has a trampoline. You go crazy jumping on it for a hour, forgetting the time because you’re just having so much fun.
When you get off, the floor feels funny underfoot, like it has lost its bounce. Aside from this strange sensation, you notice your legs hurt. They feel weak.
How did this happen? Why do your legs hurt after jumping on a trampoline?
The mesh mat of a trampoline is flexible, giving way beneath your feet when you land on it, and propelling you higher into the air than you could jump if you were on solid ground. Mat flexibility reduces the impact of your fall so you don’t hurt your knees and joints, but the flexibility also means your leg muscles have to work harder to rebound and jump again. This causes leg soreness, a breakdown of muscle tissue that results in stronger muscles after recovery.
As they say in the biz, it’s a good hurt not a bad hurt.
Trampolining, or jumping on a trampoline, burns more calories in less time than running on a treadmill or stationary cycling. Why is it such a better workout? Why are your muscles screaming after a trampoline session?
It’s all about the mat.
The mat is flexible but strong. It holds your weight when you fall after your initial jump. Instead of landing all at once like you would if you jumped out of a tree onto the dirt, you are landing on a floor that moves down with you.
Since your impact (the moment you touch the floor) is stretched out for longer, it’s also softer. This is a very good thing.
Jumping on a trampoline is really good for people who are overweight and experience knee soreness when running. It’s also great for people who struggle with joint pain in general. It’s a low-impact exercise.
The stretchiness of the mat also means that you have to work extra hard to get up off the ground. To some degree, your momentum from coming down helps you to bounce back up way higher than you could jump if you were standing on solid ground.
However, the give of the mat means that even if you’re just walking on the trampoline, your leg muscles are working harder to pick up your feet.
The mat’s interaction with your feet is gravity-based, so it sinks wherever your feet land. Instead of being able to start your next step from level ground, you have to pick your foot up from deep in the mat (sort of like walking through heavy snow).
This doesn’t just happen the first time you land after a step. Since your next step is going to sink your other foot deep in the mat, you’ll have to spend just as much energy moving that one back up again.
Taking several steps like this is bound to exhaust your muscles.
Walking on a sidewalk is easy because you can push off from the same depth every time, but the trampoline makes you push off from a different depth each time, depending on how far you’ve fallen and how deep the mat sinks in response.
All that resistance is like walking in snow or Jell-o or mud. You have you get your foot out of the mud each time before you can even move it to take another step.
The result is a breakdown in muscle tissue. Don’t worry because this breakdown of muscle tissues is actually really good for your muscles; it’s the whole point of exercise.
As those muscle tissues recover, they’ll grow back tighter and stronger. This is where we get the saying, “No pain, no gain.” Muscle-building requires muscle-working.
The Power of a Resistance Workout
A high-resistance, low-impact workout is so good for your muscles. It means less chance for a repetitive joint injury (like you get from running or playing tennis) and more chance of burning calories.
I ran cross country in high school, and every Monday we took a bus to Usery Pass, a deserty, steep trail in the beautiful Arizona Superstition Mountains.
One week, Coach Jackson took us someplace new. Instead of running on a solid dirt mountain trail and dodging jumping cactus (yes, it’s a thing!) we ran sprints in sand!
It was the hardest workout we ever did for cross country, harder than steep hills or mile repeats, even harder than dodging cactus. The reason it was so difficult was the resistance we got from the sand as our feet sank in and had to work twice as hard to get back out again.
Running as fast as you can in sand, or on a trampoline mat, is one of the most effective calorie-burning, muscle-building workouts you can get.
Too Much Resistance?
If you feel like you are getting too much of a resistance workout from your trampoline, it could be because your mat is too big for your trampoline frame or maybe your springs aren’t tight enough.
You can replace the mat or springs to make it a bit tighter and give you a better rebound with less sinking.
Another alternative is a mini trampoline. It still gives you a resistance workout and burns calories, but it’s not likely to sink as deeply as a big backyard trampoline does.
It’s got a smaller surface area and tighter connection to the frame. Many mini trampolines don’t even have springs, just straps of heavy nylon that prevent the mat from giving very much.
You can do easier bounces on a trampoline or leg-switching jumps and other dance moves. Depending on how you move, you can control how easy or hard your trampoline workout is.
You Can Do a Lot With a Trampoline
Now that you know why your legs hurt when you get off the trampoline, you can do a trampoline workout on purpose!
You can run in place on the trampoline. Doing this for 10 minutes is supposedly as good as running on a treadmill for 30 minutes. Cool, right?
Dancing on a trampoline is a thing. You can find YouTube videos with trampoline dance workouts or get grooving to the beat of your favorite songs.
Switch jumping means switching the position of your feet in mid-air so with each jump a different foot is in the front.
If you’re on a big backyard trampoline you can do air-splits, kicking both legs out at the same time and then bringing them back together as you land.
I don’t recommend doing flips or spins without supervision. It’s really easy to lose your balance or your bearings on a trampoline, to jump too far to the side and land off the trampoline, or to spin right into something else nearby.
Experiment with different ways of moving your feet on the trampoline. See which moves gives you maximum resistance without the impact.
Stay safe, and happy bouncing!