how many calories?

Question

how many calories will i burn if i bike for 3 hours at a speed of 15km/h i weigh 210 pounds (92kgs) even though i look muscular i have a bit of fat

Answer 1

Allowing for an 8 kg bike ( in good condition) at your weight it will take about 50 Watts to maintain 15 km/h (assuming little headwind). Or 43,000 calories /hour

For three hours around 129,000 calories. If this sounds high, then 129 Calories (big c or kilo calories) Also know as nutritional calories.

If your body is around 24% efficient, like mine and most other people. This would give a total burn of around 537 Calories.


There is a rough guide on this site(the graph) that says 5-15 kcal/km for a rider. This supports my calculations.
http://www.exploratorium.edu/cycling/humanpower1.html


Even heart rate monitors do not calculate that accurately there are just too many variables. The most accurate ways are to calculate rolling and wind resistance or measure output power.

Don't get to anal about measuring stuff just enjoy the ride the longer you ride, the more you will benefit.

Answer 2

In general....and this is really rough....the average cyclist burns about 25 calories per mile of riding. That's about 15 per km. Now this goes up for a rider depending on weight and intensity. If you really want to know an exact answer, you could get a heart rate monitor. By entering weight and other statistics, some HR monitors have a feature that estimates the number of calories burned.

Answer 3

Get a heart rate monitor with calorie burning setting. Thats the only way to find out exactly. Riding into the wind, uphill at 15km will burn way more calories than riding downhill or with a tailwind.