Anyone can get a good workout with bodyweight exercises. There are so many options and variations, and since they don’t require any equipment you can do them wherever you want—and for free.

But it’s also common as you do bodyweight exercises consistently and get stronger to start to feel like they’re becoming too easy. Like you need something to make them more challenging again—and that’s definitely something to celebrate. For some people it might make sense to progress to using free weights like dumbbells. But what if you’re not ready for weights or don’t have access to them? There are actually a lot of really simple ways to make bodyweight exercises more challenging without involving a single piece of equipment.

Here are a few ideas for changing up your go-to bodyweight exercises so that you can work your muscles in slightly different, more challenging ways.

1. Slow them down.

“People assume faster is better in so many cases, but the first thing you can do to make an exercise more challenging is to actually truly slow down the tempo,” Kira Stokes, celebrity trainer, group fitness instructor, and creator of the Kira Stokes Fit app, tells SELF. For example, she suggests taking three to four seconds to lower down into a squat, holding at the bottom for a count or two, and then taking three to four seconds again to stand back up. (Remember to pause for a moment at the top of the movement too!) By moving more slowly, you take any momentum out of it and rely more on strength. It also forces you to engage your core more to stay balanced longer, Stokes explains, adding a little extra core stability work. The biggest benefit, though? You’ll keep your muscles under tension (aka working) for longer.

Slowing down also forces you to think about what you’re doing, or what Stokes calls “minding your muscle.” When we do something fast, we often don’t have time to think about it and just go through the motions. When you slow things down, “you have to think about what is going on in your body and what needs to stay engaged,” says Stokes. This can help you engage the right muscles more effectively.

Stokes suggests experimenting with slowing down the entire exercise, slowing down just the lowering portion, and slowing down just the lifting portion.

2. Speed them up.

Adding speed gets your muscles working in a different way and will also get your heart rate higher more quickly, increasing cardiovascular conditioning and muscular endurance depending on how long you do it for. The most extreme way to add speed would be adding explosive power, which we know as plyometric exercises, says Stokes. Some explosive movements, she adds, can be applicable to sport-specific training, like squat jumps and one-legged jumps if you’re a runner. If you’re going to progress all the way to a plyometric (like a jump squat in which your feet come off the ground versus a regular squat in which your feet stay put), Stokes recommends starting with the regular exercise to get your muscles warmed up first. “Make it a progression,” she says.

To speed up an exercise, it may be easier to think about going for time instead of reps. So for example instead of doing 10 squats, see how many squats you can do in 20 seconds. You’ll move much more quickly and the exercise will feel a lot more intense.

3. Add a pulsing movement.

Pulsing, or getting into the hard part of an exercise and then simply moving up and down an inch each way (rather than going through the full range of motion) is just another way to keep your muscles under tension for longer. It ultimately trains your muscular endurance.

“Pulsing deep in a movement at the point that’s most challenging to hold, where you feel like you’re just not going to be able to bear it any longer, is especially great when you’re short on time,” says Stokes. “Embrace the burn that happens—that’s the good stuff,” she adds. Feeling a burning sensation in your muscles is a sign they’re working hard but feeling a sharp, stabbing, and/or sudden pain is not. Pay attention to your body and stop if you feel any pain. Stokes suggests doing about 10 reps of pulsing at a time to challenge your muscles without going overboard.

And “if you do add pulsing make sure to do a full contraction afterward,” meaning, if you’re lowered into a squat and pulsing, make sure to finish with a few reps of a full range squat, Stokes recommends. That’s because it’s just good to make a habit out of moving your muscles through their full range of motion to promote mobility and decrease tightness.

4. Make them unilateral.

This obviously doesn’t work for all movements, but for some exercises—such as deadlifts—moving from the classic version (both feet planted on the ground and both arms involved in holding the weights) to a unilateral or single-leg variation (one foot planted, the other lifting off the ground with each rep) adds an extra stability challenge, Stokes says. Another great example is a one-arm plank, in which you get into a solid plank and then slowly lift one arm off the ground and hold it by your side. This variation will engage your obliques, the muscles along the sides of your torso, even more than a regular plank because your core works overtime to keep your body stable.

5. Do more reps.

This one’s sort of self-explanatory but worth mentioning. If you’re doing bodyweight exercises and they’re starting to feel less challenging, increasing the number of reps you’re doing can make the same workouts feel harder again. That’s because more reps will increase your overall training volume or how much stress you’re putting your muscles under. When you don’t have weights, increasing the number of reps or adding an extra set to your typical workout are easy ways to push your body a little harder beyond what it’s used to.

6. Rest less.

Shortening rest intervals is a simple way to make any bodyweight workout more challenging, Stokes says. Again this is all about increasing the time your muscles are under tension without a break, but less rest will also keep your heart rate higher for longer, increasing the cardio benefits. Just always make sure to listen to your body: If you decrease rest but end up feeling lightheaded or are gasping for air throughout your workout, that’s a sign your body needs a bit more time to recover before working hard again.

7. Elevate your feet.

One easy way to make a push-up harder in particular? Put your feet up on an elevated surface. (Elevating your arms will make the move easier.) By changing the angle slightly you’re taking some of the weight off your feet and putting more weight into the upper-body muscles that you’re actually using to do the brunt of the work, forcing them to work harder. A similar phenomenon is at play with a glute bridge when you elevate your feet on a bench or step.

Another example is the deficit deadlift in which you stand on a weight plate, thereby increasing how far you’re able to lower down. Moving within a larger range of motion engages your quads, hamstrings, and glutes a bit more than a regular deadlift (and it’s actually a helpful modification for beginners to learn proper deadlift form).

8. Combine a few variations.

Sure, each of these tweaks can be effective on its own, but Stokes suggests also combining a few different variations to really spice things up. For example, start with a regular squat at a slow tempo for 5 reps. Then lower into a squat and pulse for 10 reps. And then for the next 5 reps, alternate a regular squat and a jump squat. Get creative with how you combine the different elements to make your workouts different and more challenging. “There are countless options,” Stokes says. The more comfortable you get with bodyweight exercises in their infinite variations, the better prepared you’ll be if and when you do add weights, she says.