Exercise during the winter months is hard—nothing makes parking yourself inside on the couch all day more appealing than when it’s freezing outside. But weeks of inactivity can often mean weight gain and have other negative health consequences.

If it’s too cold to head out for a brisk walk or for a loop around the running track, and if you can’t afford to splurge on a gym membership, there are a number of exercises you can do at home with little or no equipment to help stay fit, says Manhattan-based personal trainer Lisa Monaco. “Cardiovascular exercise is important to burn calories, fat and keep the heart healthy,” Monaco said. “The best cardio exercise to do at home is jump rope. If you don’t have enough room, or if you don’t have a rope, do jumping jacks. They have the same benefit.”

Monaco recommends doing either for intervals of four minutes, followed by one minute of rest, for at least 30 minutes a day. “Don’t rest too long,” she warned. “You don’t want to let your heart rate drop too low.”

Body squats are an easy move that you can do at home, and they don’t require any equipment. Here’s how to do one: stand with your feet shoulder width apart, and lower your hips towards your heels. It is not necessary to drop down lower than 90 degrees at the knee, Monaco said.

A similar exercise is the lunge. To do a lunge, start standing, take a long step forward, and drop your hips toward the floor. Then step right back to your starting position. Both lunges and squats should be done in sets of 20 repetitions. “These exercises work the largest muscles in the body, the leg muscles,” Monaco explained. “Working the largest muscles will raise the heart rate and burn a lot of calories.”

If you want to tone your arms and shoulders but can’t make it to the gym or don’t own your own set of weights, Monaco recommends simply looking around the house.

“If you don’t have dumbbells at home, you can use a can of soup or a gallon container with a handle,” she said. “Anything that weighs a few pounds or more that can be held in one hand.”

Eat a serving of protein an hour before you exercise, try to do cardio daily and weight excercises at least two or three times a week, Monaco said. “Don’t get discouraged,” she said. “It takes time to get results, but if you stick with it, they will come. Give it 6 to 8 weeks.”