Patient: Hi, when performing a bicycle crunch is it the height of the legs when raised to the chest or the closeness of the legs pressed close to the chest that burns calories. For example if i raise the leg high but dont press it close against the chest will this still burn calories or is the calories burnt determined by the pressing of the legs against the chest. Also are the legs level with the chest when they are pressed against the chest or when they are just raised to the same height as the chest but not not touching or pressing the chest. Finally, if you dont crunch the leg far up in a bicycle crunch or extend/ straighten the leg out before raising it up does this mean no calories are burnt compared to when the leg is contracted and extended at a longer length. Thankyou for your help and kind regards,Kelly.
Doctor: Thank you for choosing ATD to ask your question.Firs off, I wanna tell you that the amount of calories burnt is not a lot in crunches. To understand how calories are burnt, you can loosely follow this formula.Calories burnt = Difficulty of exercise X Time spentOne of the ways the difficulty of an exercise is measured is by checking the heart rate. The heart rate in simple exercises is not as high as it is in tough exercises like burpees or running. So, you may not be burning as much. Also, as you get more accustomed to an exercise, you will find it easier to do. This makes you more economical and burn less calories.Another issue with bicycle crunches is that because of the involvement of the back, you might become prone to injury. So be careful and stop exercising as soon as you get severe pain in the back. The best and toughest way to do a bicycle crunch is bringing your legs up to the 90-degree position with the leg completely straight and then moving them forward and down till it is almost touching the ground. One way to know this is to make that the buttock of the leg that is going down is in full contact with the ground.All this said, the calories burnt will vary from person to person based on flexibility and fitness level and each individual is unique.I recommend that you start a Cardio program like running or bicycling vigorously 3 times a week to lose calories rather than bicycle crunches. Do follow up with questions if you have more queries.Wishing you good health.