Completed my first century this weekend, heart rate monitor says I burned over 8k calories. Is this accurate?

Question

It was the livestrong challenge in philly. The course had a good bit of hills. My monitor seemed to be keeping time and mileage accurately. This just seems high but I have never gone quite this long so not sure if its normal.

Answer 1

The amount of calories the your monitor reports is only as accurate as the info put in it. If the monitor only records distance, speed and heart rate the info is close. What would make it more accurate is if it takes in account your body weight. If body weight can not be accounted for check or call the manufacture for what weight the unit is calibrated for. The reason is that a 200lb rider will burn 45% more calories than a 150lb rider for the same distance/time.
If you know your time go here and compare your monitor to this calculator. http://www.primusweb.com/fitnesspartner/jumpsite/calculat.htm

edit: Artmichalek you are right I ran an average time and weight thru the calculator link I posted and 4~5k calories would be about right.

Answer 2

The reading is not likely to be right. There is probably not a real lot wrong with your heart rate monitor either.

Heart rate monitors do their calculations based on algorithms. It assumes that you are riding alone and the head or tail wind is negligible. It also assumes you are of average fitness, size and shape. There is plenty of room for errors.

The largest error would result from riding in a large group. Wind resistance is the largest consumer of your energy. (About 80% @ 20mph on your own). If you are riding in a large group wind resistance is significantly reduced. The poor old heart rate monitor has no way of knowing this. So it thinks you are working really hard.

If you averaged around 30 mph for a century ride (solo) your calorie burn would be in the order of 8000 Calories.

The best way to measure calorie burn is to measure your output power. This requires an expensive power transducer to be fitted to your bike.

Once you know the power that you output you can then work out total calories burnt based on body efficiency. (Most people are about 24-25 % efficient).

If you don't want to outlay the money, just work on about 4000 Calories/ 100 miles @ 20mph(solo). This roughly doubles at 30 mph (solo).

Riding in a group at 30 mph is hard to gauge. (Depends on how often you take a turn on the front.) Probably more similar to riding solo @ 20 mph.

Answer 3

Order of magnitude, an average cyclist burns about 25 calories per mile of riding. That number goes up and down depending on the fitness of rider, intensity of ride, conditions, etc. I would not think it unreasonable to burn between 3,000 and 5,000 calories on a century. This just stresses why it is so important to keep eating on long rides. Your body is burning more energy on a ride than most people eat in two days. If you don't keep refueling, you won't make it.

Answer 4

congratulations . First century proves you can do it.Keep it up.
Calories burned isnt as important as recovery intake.
I can loose 5-8 lbs on a fast (for me) century. So your muscles dont start eating themselves yum yum, be concerned with good nutrition. post ride.
All the techno crap is interesting. but dont get too caught up in it. I forget to ride sometimes spending wasted moments calculating formulas etc.
Pro's are concerned because they are paid too.
Otherwise, unless u r ready to go there. Ride the centuries, double centuries, or anything, save your money for upgrades in components or for cycling swag. and have a blast.
Having ridden many centuries and practice rides equally as far, I havent bothered with the electronics. Yes a computer on all my bikes, but Im not lance. I dont make a living on bikes, but I ride 350-400 miles a week. Listen to your body. Not a machine.
Again Good job.

Answer 5

The rate of caloric burn is dependent on rider weight, average speed, and time in the saddle.

We know the distance (100 miles). What we don't know is the rider weight or the elapsed time (effort).

Note that elapsed times given below include all time spent at rest stops, etc ... not just the time in the saddle.

For a 100 mile distance:
1. Averaging less than 12 mph (elapsed time > 8:20).
- - Burn 22.6 calories per pound of rider weight (150 lb rider burns 3390 calories)

2. Averaging 12-14 mph (elapsed time 7:08 - 8:20).
- - Burn 25.9 calories per pound (150 lb rider burns 3885 calories)

3. Averaging 14-16 mph (elapsed time 6:15 - 7:08).
- - Burn 28.4 calories per pound (150 lb rider burns 4260 calories)

4. Averaging 16-19 mph (elapsed time 5:16 - 6:15).
- - Burn 30.0 calories per pound (150 lb rider burns 4500 calories)

5. Averaging 20+ mph (elapsed time < 5:00).
- - Burn 36.3 calories per pound (150 lb rider burns 5445 calories)

Answer 6

Highly unlikely...

Answer 7

That is really high. 4-5k would be more reasonable.