You don’t have to put hours in at the gym to burn calories. You may even be surprised by how many calories you burn making small movements throughout the day. Your metabolism is always working. You burn calories just by sleeping and breathing, which is called your resting metabolic rate (the calories you burn without any physical activity).

You won’t reap the same cardiovascular benefits doing small movements, but it’s easy to rev up your metabolism. You need to take a mental break at some point during the workday for your own sanity, and lounging on the couch all weekend isn’t too much fun. Try doing one of these activities to burn 100 calories in 20 minutes or less. (All calculations are for someone who weighs 150 pounds. Calories burned in a certain amount of time vary based on how much you weigh.)

Take a walk during your coffee break. In just 20 minutes, you burn 100 calories walking at a leisurely 3 miles per hour. You may even find a walk and fresh air was all you needed to boost your energy level and opt for decaf instead.

Stretch. Sitting all day can leave you with stiff muscles, and stretching for 20 minutes can help increase your flexibility and reduce stress. Burning 90 calories each time you do this is just a bonus. Before you know it, the whole office will join in.

Dance it out. If you don’t feel like hitting the gym on the weekend, blast your favorite tunes, and move to the beat. Put everything you have into it and you will reach the 100-calorie mark in just 15 minutes. If no one is watching, why not?

Ride your bike. If you live close enough to the office, consider forgoing the car, taxi, or train, and ride your bike to work instead. Not only is it good for your health (in just 10 minutes you burn 100 calories cycling at a comfortable 12 to 14 miles per hour), but it’s good for the environment too. If you can’t make the trip during the week, it’s also a fun weekend activity for the whole family.

Take the stairs. Walking three flights of stairs burns 20 calories—you can do that in no time! If you repeat this cycle five times throughout the day, you reach 100 calories. Plus, it gives you extra motivation to get out of your chair.

Wash your car. The automatic car wash is tempting, but in the 20 minutes it takes you to do the deed, you can put 100 calories in the bank. You won’t have to feel quite so guilty when you splurge on a dessert.

Garden. Work your muscles and burn some calories by digging in the dirt. When the weather is nice, it can help reduce stress. Don’t be surprised if you find yourself sweating after 20 minutes—you just burned 100 calories.