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This article examines the effects of an aerobic exercise training program on stroke volume, cardiac output, and oxygen utilization in groups arranged by race, gender, and age. Results indicate that changes in cardiovascular function and level of adaption to intense physical training were similar across groups.

This article examines the effects of an aerobic training program on blood pressure and heart rate during rest and exercise in groups arranged by race, gender, and age. Results indicate that training significantly reduced blood pressure and heart rate during exercise with black and older participants experiencing the greatest changes.

The equations developed by the HERITAGE Family Study to estimate oxygen consumption were in some ways superior to those produced by the American College of Sports Medicine (ACSM). The HERITAGE study's best equation was that using only power output, and yielded the most reliable predictions when utilizing pretraining data. Equations for post-training data, whether developed by HERITAGE or the ACSM, were equal in quality.

Background: Obesity is a major public health problem in the United States. The role of physical activity and formal exercise in controlling body weight has not been clearly determined. Objective: This study determined the magnitude of change in body weight and composition across sex, race, and age in response to 20 wk of endurance training. Design: Men and women (n = 557) of various ages (16-65 y) and 2 races (black and white) exercised on cycle ergometers 3 d/wk for a total of 60 exercise sessions starting at 55% of maximal oxygen consumption ([VO.sub.2] max) for 30 min/session and building to 75% of [VO.sub.2] max for 50 min/session, where it was maintatined during the last 6 wk. Skinfold-thickness measurements, circumferences, body composition (by hydrostatic weighing), and body fat distribution (by computed tomography scan at L4-L5 and the waist-hip ratio) were determined before and after training. Results: All skinfold-thickness and circumference measures, waist-hip ratio, body mass index, total body mass, fat mass, percentage body fat, and computed tomography scan measures of total, subcutaneous, and visceral abdominal fat decreased with training, whereas total body density and fat-free mass increased. These changes were significant, but small. There were several differences in training response by sex and race, but not by age. Conclusions: A short-term exercise intervention can induce favorable changes in body composition, but the magnitude of these changes is of limited biological significance. Increasing physical activity likely has a major effect on body-composition and fat distribution characteristics only when it is of a greater magnitude and sustained for much longer periods Am J Clin Nutr 1999;70:346-52. KEY WORDS Body composition, fat mass, fat-free mass, visceral fat, skinfold thicknesses, endurance training, weight control, obesity, HERITAGE Family Study

Accuracy of prediction equations to estimate submaximal VO2during cycle ergometry: The HERITAGE Family Study. Med. Sci. Sports Exerc.,Vol. 31, No. 1, pp. 183-188, 1999. It was hypothesized that more accurate equations for estimating submaximal VO2during cycle ergometry could be developed if more independent variables were used in the equation.

The effects of endurance running on body composition, menstrual cycles, and gonadotropins were studied in 19 healthy, young, regularly menstruating women. Midfollicular plasma concentrations of unstimulated and gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone and follicle-stimulating hormone were examined at baseline and after each subject’s weekly mileage had increased 30 miles (Δ30) and 50 miles (Δ50) above baseline. Mean±standard error of the mean unstimulated luteinizing hormone and follicle-stimulating hormone did not change significantly. GnRH-stimulated luteinizing hormone was 76.3±22.0μg/min/ml at baseline and declined to 20.2±4.5μg/min/ml at Δ50 (P<0.02). GnRH-stimulated follicle-stimulating hormone was 28.4±7.0μg/min/ml at baseline and declined to 9.6±2.1μg/min/ml at Δ50 (P<0.02). There were no significant correlations between changes in body composition and changes in gonadotropin responses. Eighteen subjects developed oligomenorrhea.