You can lose weight by burning more calories than you consume. A step aerobics workout can help you burn calories. Twenty minutes of any cardiovascular exercise, including step aerobics, is unlikely to burn enough extra calories to make a big contribution to weight loss. That is why the typical step aerobics class lasts between 40 minutes and one hour.
Step Aerobics 101
A step aerobics workout isn't much different from other group fitness aerobics options. A session consists of moving with a group of other exercisers, performing motions that tone the muscles while elevating your heart rate -- all set to music chosen to energize you and make the workout more fun. The main difference is in the use of a step -- a plastic platform that you will step or hop on and off several times during your workout. Step aerobics sessions tend to put more load on your calves, thighs and rear than do many other options.
Calories are a measure of energy, the same way kilometers are a measure of distance. Your body takes in energy in the form of food and burns that energy throughout the day. If you consume more calories than you burn, your body stores the energy for later use. If you burn more than you consume, your body accesses the stored energy to make up the difference.
What You Burn
Health resource website Harvard Health Publications provides data on the calories burned by activities ranging from cross-country skiing to sitting on your couch. According to Harvard Health, a 155-pound woman will burn approximately 173 calories during 20 minutes of step aerobics, depending on her level of effort. Heavier people will burn more calories. Lighter people will burn fewer.
Account for Variables
It's impossible to get a precise figure on how many calories you will burn in a given workout. Factors like your personal metabolism, air temperature and time of day will raise or lower your calorie consumption for any given session. However, a calorie calculator can help you estimate the calories you'll burn on average over the course of several step aerobics sessions.