How are calories burnt when performing a bicycle crunch?

Patient

Q: Hi, when performing a bicycle crunch does the leg/ knee have to be crunched up all the way to the armpit in order for the leg/ knee to be at the same height as the chest. Or does the crunching up of the leg/ knee to the armpit just burn more calories than the crunching up of the leg/knee to just the 45 degree level to the chest. Are significantly more calories burnt (eg 1 and more calories) with the crunching up of the leg/ knee to the armpit compared to the crunching up of the leg/knee to just the 45 degree level to the chest. Also, is it the crunching up of the leg that burns more calories or is it the lowering of the leg into the extended/ straightened position that burns more calories. And, does the leg being lowered as close as possible to the ground when being extended/ straightened back out burn more calories or does the height of the leg/ knee from the floor not really affect the number of calories burnt. Thankyou for your help and kind regards,
Kelly.

Doctor

A:   Hello,
Thank you for your medical query at AskTheDoctor.com
I understand your concern.

You burn more calories when the legs are brought closer to the armpit as compared to a 45 degree angle to the chest. However, the difference will be really negligible.

What actually burns calories is when the legs are raised up from the ground, as this requires immense core strength and sends the muscles into a state of contraction. When you just raise the legs above the ground and hold it for 20 seconds, you also burn calories because of the sustained state of contraction.

Raising the leg from the ground burns more calories than lowering it down. So, in that scenario, I will say the height of the leg does matter and you should get it exactly parallel to the ground without really touching the ground. But again, the difference is not huge. What burns more calories is the number of times you can perform the repetition in the given time.

Hope this was helpful,
Feel free to discuss further,
Regards.

Comments / Follow Ups

Patient: Hi, thankyou for your reply and help. So, when the leg is raised from the ground when performing a bicycle crunch, does the leg have to be raised from a fully straightened/ extended position in order to burn calories or can the leg be lowered to the ground in a slack/ bent position. Or, does the leg being lowered to the ground into a fully straightened/ extended position just burn more calories but not a significant amount. Is the leg being raised from the ground considered a contraction by the raising up of the leg into the air or by the movement of a straightened/ extended position into a crunched/ bent position. In other words does the leg have to be completely straight and extended when being lowered to the ground in order to burn calories before being raised/ crunched up, or does the slackness/ straightness of the leg not really affect the number of calories burnt. Or, are the calories burnt when the leg is contracted from a straight/ relaxed position to a bent/ contracted position or is it the raising up of the leg from the floor that causes the contraction that burns calories. Thankyou for your help and kind regards,
Kelly.
Doctor: Hello,
Although the calories burnt is not significantly high, the right way of doing it is by extending the leg fully straight so that it is parallel to the ground and then perform the next crunch.

Regards.
Patient: Hi, thankyou for your reply and help. So, in order for calories to be burnt the leg has to be extended fully straight and it won't burn calories or contract if it's not fully straight. Also, does crunching/ raising the leg/ knee to the armpit burn 1 and more calories (i need an exact number) than just raising the leg/ knee to the 45 degree or 90 degree level to the chest. And, are the same number of calories burnt when the leg/ knee is only raised/ contracted slightly (at a shorter length from the ground not all the way up to the 90 degree and beyond angle), compared to when the leg/ knee is raised/ contracted to the the 90 degree and beyond angle. Thankyou for your help and kind regards,
Kelly.
Doctor: Hello,
Even if the legs are not straight, calories will be burnt, however, lesser as compared to when it is straight.
The exact number of calories can never be predicted as every person burns calories differently because of the speed, form and the body weight. Raising it to 45 degree burns more calories than other angles.

Regards.
Patient: Hi, thankyou for your reply and help. So, when the leg/knee is raised/ crunched up to the armpit does this burn 1 and more calories (i need an exact number of calories) compared to when the leg/ knee id just raised to the 90 degree or 45 degree and beyond. Thankyou for your help and kind regards,
Kelly.
Doctor: Hello,
As I said, the exact amount of calories depends on a lot of other factors. However, it does burn more calories than when the leg is raised to 45 degrees and beyond. But, yes, the calories burnt are more. For exact number, body weight, body fat and BMI values are required.

Regards.
Patient: Hi, thankyou for your reply and help. Does crunching/ raising the leg/ knee to armpit level each time burn approximately 5-6 more calories than crunching/ raising the leg/ knee to chest level. Thanks and kind regards,
Kelly.
Doctor: Yes, it does burn 5-10 calories more based on the shape and the form in which it is done over one set of crunches.

Regards.
Patient: Hi, thankyou for your reply and help. Does raising/ crunching the leg/ knee once to armpit level burn approximately 1/2 a calorie. Thanks and kind regards,
Kelly.
Doctor: Hello,
Yes it does compared to raising it till the chest only.

Regards.
Patient: Hi, thankyou for your reply and help. So raising/ crunching the knee once to only chest level burns less than 1/2 a calorie but raising it to armpit level burns 1/2 a calorie each time. Also, do 4 crunches burn 1 calorie for a 100lb female performing them. And, in order to burn more calories does the leg/ knee have to be raised/ crunched up from a lower position to the ground as possible. In other words when the leg is raised from the ground or as near the ground as possible does this burn more calories than just rasing the leg from a higher position. Thankyou for your help and kind regards,
Kelly.
Doctor: Hello,
Yes, raising it to armpit burns 1/2-1 calorie more. It is an estimate.
4 crunches burns around 1 calorie, for a 100 lb female.
Yes, I mentioned that before too. It should start from as lower to the ground as possible.

Regards.
Patient: Hi, thankyou for your reply and help. Does performing the bicycle crunches in this manner continuously (at a fast pace or without breaks) burn 1 calorie for every 4 crunches, or does performing the crunches at a slow rate or with breaks still burn 1 calorie for every 4 crunches. Also, does 3 bicycle crunches burn 1 calorie for a 100lb female or is if 4 crunches that burn 1 calorie for a 100lb female. And, are significantly more calories burnt after performing the exercise in excessive post oxygen consumption. Thankyou for your help and kind regards,
Kelly.
Doctor: Yes, a continuous form is necessary for burning constant calories. 4 crunches burn 1 calorie.

Yes, more calories are burnt after performing exercise in excessive post oxygen consumption.

Kindly post a fresh query if you have additional questions. I will be happy to help.

Regards.

Related Q&A

Q: During and after exercise parts of my skin become become very red and feel very hot. Have you any idea what this coul...

Q: Hey there. I'm a 55 year-old male and I was wondering if my Aortic Arch looks "normal" on this CT Scan? Ext...

Q: I was working out last week doing various squat exercises and ended up squeezing my vagina muscles way more than I sh...

Q: Hi the week before last i started a new job and manage to find a go go pill I took it last wednesday its a insurance...

Q: 83yr old male,6"185 lb,exercises reg,3times a wk for 11/2 hr.Currently treated for hi bld pres with low dose ado...

 
DOCTOR ADVISORY BOARD
218

Dr. James Obaji M.D.

  • 247 Reviews
  • Family Physician
173

Dr. Suneel Sharman M.D.

  • 190 Reviews
  • Family Physician
138

Dr. Pat Golden M.D.

  • 169 Reviews
  • Cardiologist
98

Dr. Kunaal Jindal M.D.

  • 112 Reviews
  • Plastic Surgeon
CNN
BBC
MSNBC
CBS
abcNews
FoxNews