You will lose weight during your first boxing class although your weight loss might be imperceptible. How much weight you lose during boxing classes depends on how active you are during the class, the kind of boxing you're involved in, your exercise heart rate and your weight. Improving your boxing skills enough to participate in a bout can help you lose even more weight because boxing in a ring burns more calories than most other exercises.
Your first boxing classes will consist largely of listening to instructors, emulating their techniques, and preparing to box by stretching your arms and legs. These activities burn few calories. Standing for one hour burns an average of 94 calories if you're 155 lb., according to a "Harvard Heart Letter" report. Stretching for one hour burns 281 calories if you're 155 lb., according to Wisconsin's Division of Public Health. You lose 1 lb. when you burn 3,500 calories. Practicing boxing moves raises your heart rate. Higher heart rates requires more oxygen, which causes you to burn more calories. Your exercise heart rate should be 65 percent of its maximum to improve your fitness, or 220 heartbeats per minute minus your age, according to exercise expert Dr. Kenneth Cooper.
Boxing instructors will probably allow you to practice the techniques you learned on a punching bag before you spar with classmates. During a one-hour class, you might spend 30 minutes hitting a punching bag while practicing the footwork you learned and another 30 minutes learning more techniques. The instructor might also give you tips after observing your technique. Boxing a punching bag for one hour burns 422 calories if you're 155 lb. and 518 calories if you're 190 lb., according to the Wisconsin report. That means you need to punch a bag for slightly more than eight hours to lose 1 lb. if you're 155 lb. and slightly less than seven hours to lose 1 lb. if you're 190 lb.
Your boxing instructors will probably allow you to spar with classmates as your technique improves. Sparring requires a lot more movement, effort and energy than punching a bag because you need to avoid, block and absorb your opponent's punches while working harder to land your punches. Sparring for one hour burns 633 calories if you're 155 lb. and 776 calories if you're 190 lb. Consequently, you need to spar for about 5.5 hours to lose 1 lb. if you're 155 lb. and about 4.5 hours to lose 1 lb. if you're 190 lb.
Many boxers run and jump rope as they prepare for bouts. A 155-lb. person burns 950 calories per hour running 8 mph and 704 calories per hour jumping rope at a moderate speed. Running is one of the fastest ways to lose weight, but boxing in a ring ranks 13th among 178 exercises studied by Wisconsin. It burns 844 calories per hour if you're 155 lb. and 1,035 calories per hour if you're 190 lb. You will lose 1 lb. boxing in a ring in slightly more than four hours if you're 155 lb. and slightly more than three hours if you're 190 lb.