Single Session Of Aerobic Exercise Research Articles

DIET AND SHORT TERM PLASMA LIPOPROTEIN-LIPID CHANGES AFTER EXERCISE IN TRAINED MEN

1887 To test the effect of diet on the short-term lipid response to exercise, fourteen moderately trained (V̇O2max: 50.2 ± 6.7 ml·kg−1·min−1), healthy men (mean age: 27.8 ± 4.3 yr) were alternately fed a high fat (60 ± 6.7 % fat) and a high carbohydrate (63 ± 3.2% carbohydrate) isoenergetic diet for two weeks in a randomized crossover design. During the last four days of the treatments, fasting total cholesterol, triglyceride, HDL-cholesterol, and HDL3-cholesterol were measured the day before, and again immediately, 24 h, and 48 h after exercise (4190 kJ, 70% V̇O2max). LDL-cholesterol and HDL2-cholesterol were calculated. Lipid concentrations were adjusted for plasma volume changes after exercise. A 2 (diet) × 4 (time) ANOVA with repeated measures revealed no significant interaction between the diet and exercise treatments. Furthermore, diet alone did not influence lipid concentrations in these trained men. Exercise resulted in an increase in HDL-C (10.7%) and HDL3-C (8.5%) concentrations and a concomitant fall in triglyceride (−25%) and total cholesterol (−3.5%). Thus, we conclude that diet composition does not affect the short-term changes in blood lipids and lipoproteins that accompany a single session of aerobic exercise in moderately trained men.

The Influence on Blood Pressure During Daily Activities of a Single Session of Aerobic Exercise

Previous research has examined the effectiveness of a single session of aerobic exercise in lowering blood pressure responsivity to the subsequent presentation of a nonexercise stressor in the laboratory. This case study was designed to explore the possibility that a single session of aerobic exercise might lower blood pressure for up to 4 hours postexercise as the subject engaged in his usual activities at home and at work. The subject was an untrained, unmedicated, borderline hypertensive who underwent ambulatory blood pressure monitoring as he maintained a normal schedule of activities over a 5-day period. On 2 of the 5 days, the subject exercised at 8:30 AM for 30 minutes at 70% VO2max. Blood pressure readings on days when the subject read for 30 minutes were compared with readings on days when he exercised. He showed an average reduction in systolic blood pressure of 26.4 mm Hg at 2 hours after exercise, 24.2 mm Hg at 4 hours afterward, and 12.2 mm Hg at 9 hours after the exercise. Changes in diastolic blood pressure and heart rate were smaller and less consistent. The authors concluded that the modifying influence of a single session of aerobic exercise on blood pressure responsivity to subsequent laboratory-based stressors may also extend to the natural environment. The discussion addresses theoretical, methodological, and clinical considerations in the use of aerobic exercise to modify excessive blood pressure reactivity.

Acute Emotional and Cardiovascular Effects of Stressful Mental Work During Aerobic Exercise

The acute effects of engaging in challenging mental work during a single session of aerobic exercise were examined on measures of subjective mood and cardiovascular function. Fifty-seven female subjects were randomly assigned to participate in either a 10-min aerobic exercise condition or a no-exercise control condition. Half of the subjects in each group performed digits backward problems during this time period, and no mental stressors were presented to the other subjects. The results indicated that the exercise and mental stress conditions had additive effects on subjective anxiety levels and on cardiovascular responses during exercise. Both exercise and mental stress increased heart rate. In addition, exercise had anti-anxiety and vasodilative effects, but both of these influences were attenuated by opposing main effects for mental stress exposure. No effects were found for exercise on measures of cardiovascular reactivity to a later digits backward stressor. The results are consistent with previous research in suggesting that exposure to mental stressors during aerobic exercise provides no acute psychological benefits but attenuates some of the mood improvements and vasodilative effects of the exercise activity.