Evan:
I'm on the faculty at Georgia State University in Atlanta, with a specialty in Exercise Physiology. I have a particular interest in golf - from a professional as well as personal standpoint. Based upon the research studies I have read, I think those numbers are pretty accurate.
Most studies have estimated caloric expenditure while walking the golf course either using caddies or a pull cart. Caloric expenditure ranges from 4 - 6 kcal per minute or 240 to 360 kcals per hour.
There aren't too many studies that have looked at caloric expenditure while walking and carrying your clubs, but one that I am familiar with estimated energy expenditure from heart rate while walking and carrying on flat, moderate, and hilly golf courses. As you would expect, you burn more calories when carrying your clubs, and burn more calories as the course gets more hilly. This study showed caloric expenditures of 435 kcal/hour on a flat course up to 495 kcal/hour on a hilly course.
Because of the difficulty of actually measuring energy expenditure while doing a long duration, free-living activity like golf, most studies estimate energy expenditure from heart rate. A lot of other factors can affect heart rate during a round of golf, though - stress, heat, etc. One recent study used a portable device to directly measure energy expenditure while walking (with a pull cart) and playing 2 holes of golf - the energy expenditure was 5.4 kcal per minute or 324 kcal per hour.
A number of studies have also estimate the distance walked during an 18-hole round; reports range from 4-6 miles. These are often estimated from the course length and estimates of the distance from green to tee, etc. I think the estimates might be on the low end. I've been doing some preliminary studies using a GPS system to more accurately measure distance walked - I usually cover about 4.5 miles when I walk 18 holes on the executive-length course I usually play (course length only 3357 yards).
Figuring caloric expenditure sounds precise, but is actually a somewhat ballpark proposition. One of the main factors is body size - larger people simply expend more energy to move their mass. If you want to get an idea of your caloric expenditure, it probably makes most sense to use figures that are relative to your body weight.
If you walk and use a pull cart (or a caddy), figure on approximately 2 kilocalories per pound of body weight every hour.
If you walk and carry your clubs, figure up to a maximum of 3 kilocalories per pound of body weight per hour.
Hope this helps,
Andy
Reference List
1. Burkett, L. N. & von Heijne-Fisher, U. (1998). Heart rate and calorie expenditure of golfers carrying their clubs and walking flat and hilly golf courses. International Sports Journal, 78-85.
2. Getchell, L. H. (1968). Energy cost of playing golf. Arch Phys.Med Rehabil., 49, 31-35.
3. Hendelman, D., Miller, K., Baggett, C., Debold, E., & Freedson, P. (2000). Validity of accelerometry for the assessment of moderate intensity physical activity in the field. Med.Sci.Sports Exerc., 32, S442-S449.
4. Lampley, J. H., Lampley, P. M., & Howley, E. T. (1977). Caloric cost of playing golf. Res.Q., 48, 637-639.
5. Murase, Y., Kamei, S., & Hoshikawa, T. (1989). Heart rate and metabolic responses to participation in golf. J.Sports Med.Phys.Fitness, 29, 269-272.
6. Stauch, M., Liu, Y., Giesler, M., & Lehmann, M. (1999). Physical activity level during a round of golf on a hilly course. J.Sports Med.Phys.Fitness, 39, 321-327.
7. Unverdorben, M., Kolb, M., Bauer, I., Bauer, U., Brune, M., Benes, K. et al. (2000). Cardiovascular load of competitive golf in cardiac patients and healthy controls. Med Sci Sports Exerc., 32, 1674-1678.