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### Exercise

This page contains information about the energy consumed during certain exercises. These formulas are very useful for keeping track of your exercise program, especially if you get exercise in a variety of different ways. Keeping track of calories consumed is useful for several reasons:

• First, tracking energy expenditure makes different exercises comparable.
• Secondly, if you are trying to lose weight, paying attention to calories consumed (the food you eat) and calories burned can give you a good idea of how much weight you can expect to lose.
• Finally, energy is really the appropriate measure for exercise because energy is an integrated measure effort and time.

The page includes a longer section on bicycling, and a summary table. Choose cycling or other exercises on the left, or from the links below.

• Information about bicycling, including the speed vs. rate of energy consumption relationship.
• Rate of energy consumption for other activites.

#### Bicycling

One of the puzzles of bicycling that has always interested me is the relationship between speed, distance and the amount of energy expended during a bicycle ride. Knowledge of this relationship allows the rider to make decisions about how far or fast to ride in order to burn a specific number of calories (Kcal). Data from metabolic trials on bicycle riders can be used to discover this relationship.

The graph on the right shows the relationship between speed and the rate of energy consumption for a 150 pound rider under three different conditions. The top curve (in green) shows a bicyclist riding on a gravel road with a mountain bike, the middle curve (in blue) is a bicyclist on a paved road riding a touring bicycle, and the lowest curve (red) shows a racing bicyclist. Data for the bottom two relationships comes from Whitt, F.R. & D. G. Wilson. 1982. Bicycling Science (second edition). The MIT Press, Cambridge MA. p.37.

These relationships can be written as follows, where y represents the rate of energy consumption in Kcal / min for a 150 pound rider, x represents the average speed travelled in miles per hour, and exp(a) means e to the power of a:

• Mountain bicycling: y = 1.47 * exp(0.144 * x)
• Touring: y = 1.41 * exp(0.125 * x)
• Racing: y = 1.34 * exp(0.107 * x)

As is evident from these relationships, speed is important, but if a rider is trying to increase the number of calories consumed in a ride, it is far better to increase the distance travelled (and therefore the amount of time riding) than to increase the speed travelled. For example, a 20 mile ride with an average speed of 19 mph on a touring bicycle works out like this: rate of energy consumption = 1.41 * exp(0.125 * 19) = 15.2 Kcal / min. A 20 mile ride at 19 mph takes 63 minutes, so the total energy consumed over the course of the ride equals 63 * 15.2 = 958 calories. If the rider increases his or her speed to 20 mph, the total energy consumed is 1032 calories. This is equivalent to riding 21.5 miles at 19 mph, or riding for 68 minutes at 19 mph. In other words, the same amount of energy is consumed by riding for 8 additional minutes at 19 mph, versus 20 mph.

#### Other Activities

The following table shows the amount of energy consumed for various activities. The figures in the right-hand column (or the results of the equations) are expressed as kilocalories / minute / kilogram. Calories, as reported on food labels are actually kilocalories, so the results from this table can be interpreted in the same way as food labels.

These figures and equations were derived from a variety of sources, including:

• Fixx, J. F. 1977. The Complete Book of Running. Random House, New York, NY.
• Lamb, D. H. 1984. Physiology of Exercise: Responses and adaptation. MacMillan Publishing Company, New York, NY.
• McArdle, W. D., F. I. Katch & V. L. Katch. 1986. Exercise Physiology: Energy, nutrition and human performance. Lea & Febiger, Philadelphia, PA.
• Whitt, F. R. & D. G. Wilson. 1982. Bicycling Science (second edition). MIT Press, Cambridge, MA.

To use these tables, you need to know how much you weight in kilograms, and how many minutes you participated in the activity. Several of the activities have other variables related to how hard you were working while you were exercising. To convert between pounds and kilograms, simply multiply your weight in pounds by 0.45. The following are some conversions:

 Weight(pounds) Weight(kilograms) 100 45 120 54 140 63 160 72 180 81 200 90

For example, on the first part of a backpacking trip I took recently, I hiked for about 8 hours with a pack that weighted 70 pounds. I weigh 150 pounds, so my pack is 46% of my weight (70 / 150). My weight in kilograms is 67.5 Kg (150 * 0.45). Eight hours is 480 minutes (8 * 60). As shown below, the equation is 0.07 * (1 + pack weight) * number of minutes * weight in kilograms. This works out to be 3,327 Kilocalories (0.07 * 1.46 * 480 * 67.5). Remember that Kilocalories are the same thing as the calories that are printed on food labels.

 Exercise Equation, Estimate(All results in kcal / min / kg) Aerobics (standard) ( 0.024 * level ) + 0.0434level: 1-5 Aerobics (step) ( 0.0082 * height * rate / 120 ) + 0.0516 height: inches, rate: steps / min Basketball half court: 0.1389full court: 0.1940 Bicycling mountain bike: 0.0216 * e( 0.144 * speed) touring bike: 0.0207 * e( 0.125 * speed) racing bike: 0.0201 * e( 0.107 * speed) speed: miles / hour Canoeing ( 0.0438 * speed ) - 0.0435 speed: miles / hour Football (touch) 0.1342 Golf cart: 0.0458 pull clubs: 0.0760 carry clubs: 0.0878 Hiking 0.07 * ( 1 + pack weight )pack weight: percent of body weight Raquetball 0.1520 Rowing ( 0.0329 * speed ) + 0.0338speed: miles / hour Running ( 0.0024 * speed2 ) - ( 0.0104 * speed ) + 0.1408 speed: miles / hour Scuba 0.1130 Shoveling snow light snow: 0.1336 medium snow: 0.1717 heavy snow: 0.2098 Skating low speed: 0.0833 medium: 0.1142 high: 0.1451 Skiing (downhill) 0.1060 Skiing (cross-country) ( 0.0153 * speed ) + 0.0619 speed: miles / hour Snowshoeing 0.1660 Soccer 0.1402 Swimming, crawl ( 0.0037 * speed ) - 0.0006 speed: yards / minute Tennis singles: 0.1151 doubles: 0.0731 Volleyball low intensity: 0.0588 high intensity: 0.1256 Walking ( 0.008 * speed2 ) - ( 0.0301 * speed) + 0.0822 speed: miles / hour Walking upstairs 0.2573 Yoga 0.0578