Cardiovascular response to sudden strenuous exercise: an exercise echocardiographic study.

We studied the response in left ventricular (LV) internal dimensions and posterior wall thickness during the performance of sudden strenuous exercise without warm-up (SSE) and sudden strenuous exercise with warm-up (SSEw) in 15 healthy, untrained college-aged males (26 +/- 5.0 yr). Measurements of left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD), stroke dimension (SD = LVEDD-LVESD), fractional shortening (FS = SD/EDD) and posterior wall thickness (PWT) were obtained from continuous 2-D targeted on M-mode echocardiography. Continuous EKG and blood pressure were obtained at rest and during the final 10 s of SSE (30 s of upright leg cycle ergometry of 400 W at 80 rpm). SSEw was preceded by warm-up exercise (6 min of graded leg cycle exercise of 2-min stages initial load 30 W, increasing in 30-W increments at 60 rpm, followed immediately by SSE). Our findings revealed that there were no significant differences in the LV internal dimensions (LVEDD, LVESD, FS, PWT), HR max, RPP max, ECG, and MAP max between SSE and SSEw. Sudden strenuous exercise without warm-up is not associated with a reduced LV function. The results of this study are contradictory to previous findings that have suggested that SSE is associated with transient global left ventricular (LV) dysfunction.

Is exercise indicated for the patient diagnosed as anorectic?

1. Anorexia nervosa is a disorder characterized by voluntary decreases in food intake resulting in negative caloric balance and dramatic loss of body weight. 2. Aerobic exercise may be contraindicated in patients diagnosed with anorexia because of the high caloric cost and the possibility of overindulgence. 3. Calorically modest weight lifting exercises to increase lean body mass might be useful in increasing compliance with therapy by ensuring that the weight gained is distributed in a more aesthetically appealing manner.

Accuracy and reproducibility of an exercise prescription based on Ratings of Perceived Exertion for treadmill and cycle ergometer exercise.

The accuracy of regulating exercise intensity by Ratings of Perceived Exertion (RPE) was examined. Subjects underwent 4 production trials, 2 on a treadmill (P1A, P1B) and 2 on a cycle ergometer (P2A, P2B). 9 untrained subjects used only their perceptions of effort to regulate exercise intensity. Target intensity was the RPE equivalent to 60% VO2max. Exercise intensity (VO2) during P1A, P1B, and P2A did not differ from the target, but during P2B was lower than target. During P1A and P1B heart rate did not differ from the target but was lower than target during P2A and P2B. RPE seems a valid means of regulating exercise intensity during repeated bouts of treadmill exercise at 60% VO2max; however, exercise intensity during repeated bouts on the cycle ergometer may be lower than target.

Effects of different exercise training intensities on lipoprotein cholesterol fractions in healthy middle-aged men.

Exercise training has been associated with decreases in total cholesterol and increases in high-density lipoprotein (HDL) cholesterol. The effect of the intensity of the exercise on alterations in cholesterol and lipoprotein fractions has not been defined and is the subject of this study. We divided 49 healthy men (aged 44 +/- 8 years) into four groups and evaluated them before and after 12 weeks of cycle ergometer exercise training at (1) an intensity of 65% of maximal achieved heart rate, (2) 75% maximal heart rate, (3) 85% maximal heart rate, and (4) a 12-week nonexercise control period. Pre- and post-training evaluations included maximal ergometer exercise ECG examinations with measurement of maximal minute oxygen consumption and serum total cholesterol, HDL cholesterol, and triglyceride levels. Low-density (LDL) and very low-density lipoprotein (VLDL) cholesterol levels were calculated. Dietary histories were obtained before and after the training period, and body weight and percentage of body fat were measured. Post-training oxygen uptake was significantly increased (training effect) in the groups exercising to 65%, 75%, and 85% maximal heart rate. Results of within-group analysis showed significant increases in the HDL cholesterol fractions in the 75% and 85% groups but not in the 65% group or the control group. Significant decreases in calculated LDL fractions occurred only in the 75% exercise-trained group with maximal heart rate. Aerobic exercise training favorably alters plasma lipoprotein profiles. A minimum training intensity equal to 75% maximal heart rate is required to the increase HDL cholesterol level.