Nutrition and exercise

HDL-cholesterol: exercise formula. Results of long-term (6-year) strenuous swimming exercise in a middle-aged male with paraplegia

Paraplegic individuals are at increased risk for developing heart disease because of low HDL-cholesterol levels. Exercise has been identified as an important factor in raising the HDL-cholesterol level. This case study documents the effects of long-term (6-year) strenuous exercise (2940 kcal/wk) on lipid markers in a 41-year-old white male with paraplegia. An additional 21 mg of HDL-cholesterol (84% increase) were observed in a paraplegic individual who swam 2100 kcal/week for 6 years. Througout this study, serial blood samples were analyzed for total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. An initial low HDL-cholesterol of 25 mg/dl was measured in the subject. This case study continued for 72 months to determine the long-term effects on various blood lipid fractions of swimming an additional 2.5 hours/week. HDL-cholesterol slowly increased over the duration of the study. After 12 months of swimming the HDL fraction had increased from 25 mg/dl to 31 mg/dl. After 24 months and at the end of 72 months of swimming, the HDL fraction had risen to 43 mg/dl and 46 mg/dl, respectively. The estimated long-term energy cost for each additional 1 mg/dl of HDL-cholesterol above the pre-exercise HDL value was 100 kcal/week in this subject. Long-term strenuous swimming exercise has been successfully incorporated into the lifestyle of a paraplegic individual. Significant reduction in known coronary risk factors followed a marked increase in the HDL-cholesterol level.

Does aerobic conditioning cause a sustained increase in the metabolic rate?

We measured the metabolic rate by indirect calorimetry for 90 minutes following exercise in six healthy individuals. Ten and 30 minutes of cycling at 80% of maximal intensity produced comparable increases in the resting metabolic rate, (37% and 32%, respectively) immediately after exercise. However, by 30 minutes following exertion, the metabolic rate was not different from control values. The total additional caloric use during the 90 minutes of recovery was similar for the two exercise durations, and the mean increment in recovery energy expenditure was 11.4 +/- 7.1 kcals. The majority of caloric use with exercise is during the activity. Recovery energy expenditure following usual aerobic training results in only a minor contribution to total energy use.