Whenever I’m getting my sweat on, I undoubtedly aim to move myself harder/bester/faster/stronger. I like to feel like I’m truly kicking my own butt, and leave my workout exhausted and sore. Hence why any workout class that’s meant to move slowly—or even not at all—is super challenging for me (sup SLT?!).

In actuality though, fitness trainers don’t necessarily say that you need to be going so hard to get the best results out of your workout. Enter “still” exercises, like yoga’s boat poses and Pilates’ hollow holds, which can give your sweaty moves a run for their money.

“A still exercise is also known as an isometric exercise in the fitness industry,” says Autumn Calabrese, Beachbody super trainer and creator of 21 Day Fix. “Isometric exercises are beneficial because they don’t add a lot of extra impact to your joints and can be performed without any equipment. They’re good for building strength without impact or full range of motion, which is great for someone who’s recovering from an injury or just wants to take it easy on their joints.”

You can make these moves even harder by adding weights, too. “This puts the muscle under tension for a longer period of time, which is what’s needed for gains in strength,” she adds. Of course, these muscle-blasting moves do come with certain limitations. “Isometric contraction only increases muscular strength in the exact position you’re engaging,” Calabrese explains. “So you need to perform various isometric exercises to help strengthen different muscles, rather than using compound exercises that can work multiple muscles.” Her take? “Still” exercises are your best bet when used in addition to your regular strength training.

Keep scrolling to try out Calabrese’s go-to still exercises for a real burn.

1. Plank: You know the drill—get onto the floor with your arms bent at 90 degrees and elbows directly underneath your shoulders. “Rest on your elbows and lift your torso off the ground so you are on the balls of your feet and your elbows, being in one straight line from the top of your head to your tailbone,” she says. “Press your shoulders down, squeeze your bellybutton into your spine to engage your core, squeeze your inner thighs and glutes, and hold the pose for 10 to 60 seconds.” Or longer, if you so desire.

2.Squat: Sure, you can squat until your ass is on fire, but when you do an isometric hold of a squat, it’ll really strengthen your lower body. “Lower yourself down into a squat with your feet hip width apart and toes facing directly forward,” says Calabrese. “Your abdominals are engaged and chest is up. Don’t let the upper back round.” Just hold it in that position for 10 to 60 seconds while squeezing your quads, hamstrings, and glutes—trust me, you’ll be feeling it.

3. Glute bridge: While lying on your back, Calabrese says to bend your knees with your feet flat on the ground. “Keep your heels close to your butt and push your heels into the ground while lifting the hips into the air,” she says. “Squeeze your glutes and your abs, and keep your hips lifted as high as possible.” Hold for 10 to 60 seconds. You’ll see that there’s legit power in stillness.

For the rest of your fitness regimen, here’s what trainers say about doing cardio or strength training first. And this is what it means if your feet are always cramping after your workout.