PHYSICS RESOURCES DATABASE
THERMAL PROPERTIES
Energy consumed during activity
In animals, oxidation takes place in a long sequence of chemical changes, but the utilization of oxygen plus foods and the production of carbondioxide as a gasesous by-product is the characteristic of the overall reaction.
The basal metabolic rate (BMR) is the rate necessary to keep an animal at rest alive. For humans it is about 170 kJ.m-2.h-1, which is about 290 kJ.h-1 for a person with 1.7 m2 of surface area. Measurements of the rate of oxygen usage indicate an average ratio of about 20 kJ.L-1 of oxygen.|
ACTIVITY |
ENERGY kJ.h-1 per kg body mass |
O2 need L.min-1 |
|
Sleeping |
4.2 |
0.24 |
|
Lying quietly |
4.8 |
0.27 |
|
Sitting on the grass |
6.0 |
0.34 |
|
Standing in line |
6.7 |
0.38 |
|
Driving a car |
8.5 |
0.48 |
|
Office work |
8.8 |
0.50 |
|
Strolling through a park |
10 |
0.58 |
|
Bike ride (level, 10 km.h-1) |
13 |
0.72 |
|
Brisk walking (level, 6 km.h-1) |
18 |
1.03 |
|
Walking uphill (5% grade, 5 km.h-1) |
22 |
1.24 |
|
Walking down stairs (normal) |
25 |
1.43 |
|
Making beds |
25 |
1.44 |
|
Swimming (freestyle, 2 km.h-1) |
27 |
1.51 |
|
Skiing (level, 5 km.h-1) |
33 |
1.89 |
|
Rowing (5.6 km.h-1) |
40 |
2.27 |
|
Running (level, 9 km.h-1) |
44 |
2.47 |
|
Skating (level, 20 km.h-1) |
47 |
2.68 |
|
Running (level, 11 km.h-1) |
53 |
2.99 |
|
Running up (grade 9%, 11 km.h-1) |
58 |
3.26 |
|
Football |
61 |
3.44 |
|
Walking up stairs (normal) |
67 |
3.78 |
|
Running (level, 18 km.h-1) |
79 |
4.47 |
|
Swimming (breast stroke, 4.3 km.h-1) |
218 |
12.37 |
|
Running (level, 25 km.h-1) |
236 |
13.40 |