Oded Bar-Or

Load Optimization for the Wingate Anaerobic Test

SummaryThe purpose of the present study was to define the optimal loads (OL) for eliciting maximal power-outputs (PO) in the leg and arm modes of the 30 s Wingate Anaerobic Test (WAnT). Eighteen female and seventeen male physical education students, respectively 20.6±1.6 and 24.1±2.5 years old, volunteered to participate. In each of the total five sessions, the test was administered twice on a convertible, mechanically braked cycle-ergometer, once for the legs and once for the arms. The five randomized, evenly-spaced resistance loads ranged from 2.43 to 5.39 Joule per pedal revolution per kg body weight (B. W.) for the legs, and from 1.96 to 3.92 for the arms. The measured variables were mean (MP·kg−1) and peak PO as well as absolute and relative measures of fatigue. A parabola-fitting technique was employed to define the optimal loads from the MP·kg−1 data. The resulting OL were 5.04 and 5.13 Joule·Rev−1·kg B.W.−1 in the leg and 2.82 and 3.52 in the arm tests for the women and men, respectively. OL were shown to depend on PO magnitude. However, within a two-load span (0.98 Joule·Rev−1·kg B.W.−1) about the OL, MP·kg−1 did not vary by more than 1.4% in the leg and 2.2% in the arm tests. It is suggested that although the WAnT is rather insensitive to moderate variation in load assignment, improved results could be obtained by using the stated OL as guidelines that may be modified according to individual body build, composition, and, particularly, anaerobic fitness level.

Follow-up of normotensive men with exaggerated blood pressure response to exercise

The early detection of hypertension is of foremost concern. It may be that individuals who are normotensive at rest but who show an exaggerated blood pressure (BP) response to exercise are at greater risk of developing hypertension in the future. From exercise tests, a group (ER) of healthy young males who were normotensive at rest (BP less than or equal to 140/90) but showed an exaggerated BP response to exercise (systolic BP greater than or equal to 200 mm Hg and/or diastolic BP 10 mm Hg to greater than 90 mm Hg) were selected. A control group (NR) with exercise BP values less than these were matched for age, weight/height, skinfold thickness, resting BP less than or equal to 140/90, resting heart rate, aerobic fitness level, physical activity, smoking history, and family history of hypertension. After a follow-up period of 5.8 years (range 3 to 14 years) eight of the subjects from the ER group were found to be hypertensive, whereas none of the NR group were hypertensive. Stepwise multivariate regression showed the exercise blood pressure to be the best predictor of future blood pressure of the parameters reviewed in this study. Exaggerated BP response to exercise may serve as an additional risk marker for hypertension.

Anaerobic characteristics in male children and adolescents.

Only sparse information has been published on the effects of growth, development, and maturation on the ability to perform high intensity, short-term anaerobic tasks. Cross-sectional studies on Italian, African, British, and American females and males have indicated an age-related progression in the performance of the Margaria step-running test. Children had a distinctly lower mechanical power output than adolescents and young adults, both in absolute terms and when divided by body weight, or by fat-free mass. Data are presented on some 300 10- to 45-yr-old Israeli males who performed the Wingate anaerobic test by cycling or by arm cranking. Both the peak power at any 5-s period and the mean power throughout the test were lowest in the children, whether expressed in absolute power units or corrected for body weight. Performance progressed with age and reached the highest values at the end of the third decade for cycling and at the end of the second decade for arm cranking. This pattern is unlike that described for maximal O2 uptake per kg body weight which, in males, remains virtually unchanged from childhood to young adulthood. In females, maximal O2 uptake per kg is even higher in children than among adolescents or adults. Biochemical correlates of such a low anaerobic performance in children are their lower maximal lactate concentration in muscle and blood, lower rate of anaerobic glycolysis, and lower levels of acidosis at maximal exercise. The mechanisms for the relatively deficient anaerobic characteristics of children are not clear.

Effects of dry and humid climates on exercise-induced asthma in children and preadolescents

Among factors which possibly influence the responses of asthmatic children to exercise, climate has received little attention. This study was performed to determine whether the level of air humidity is a factor to be considered. Twenty asthmatic (extrinsic perennial) girls and boys, 6 to 14 yr of age, with unverified history of exercise-induced asthma (EIA) took part. They rested and exercised in a climatic chamber in dry (25% relative humidity) and humid (90%) sessions at 25 degrees to 26 degrees C. One to three weeks separated the sessions, the order of which was counterbalanced. No changes in pulmonary functions (FVC, FEV 1.0, MMEF, MBC) were found following a sitting period of 60 min in either climate. Five and ten minutes following the treadmill run, however, bronchoconstriction was distinctly more pronounced in the dry than in the humid climate. Exercise heart rate and the subjective rating of effort were not affected by climate. It was concluded that, under the above experimental conditions, EIA is more likely in dry air than in humid air, possibly due to heat loss at the airway mucosa caused by evaporation. High humidity of inspired air could be the reason why EIA is less prevalent in swimming, as compared with other modes of exercise.

Responses to Exercise of Paraplegics Who Differ in Conditioning Level.

The purpose of this study was to evaluate the cardiopulmonary function and body composition of sedentary and highly active paraplegics. Four age-matched groups of men (n = 41) were studied: wheelchair-bound sedentary (WS), wheelchair-bound athletes of international caliber (WA), able-bodied sedentary (NS), and able-bodied athletes of national Israeli teams (NA). Although of similar height, WS were significantly (p less than .05) heavier and more obese (skinfolds) than WA and NS. Maximal oxygen consumption (VO2max arm), as measured during arm ergometry by direct open circuit spirometry, was significantly lower in WS (19.58 plus or minus 5.53 ml/kg per min) than in WA (35.00 plus or minus 7.55). The latter had significantly higher VO2max arm than did NS (25.79 plus or minus 3.98). However, no significant difference was observed between WA and NA (38.05 plus or minus 6.25). A similar trend, favoring WA over WS, was shown for maximal minute ventilation and maximal oxygen pulse. Functional lung volumes (FVC, FEV1.0, MBC) did not differ significantly between WA and WS. Heart rates at submaximal work loads were higher in WA than in NA, but markedly lower than in WS. Clear-cut conclusions can be obtained only by a longitudinal study, but these data suggest a marked decrement in cardiopulmonary functions, related to the oxygen transport system, in men whose lower limbs have been immobilized for years. A reversed trend is shown for paraplegics who regularly activate their upper limbs and trunk muscles.

Physiological and perceptual indicators of physical stress in 41-to 60-year-old men who vary in conditioning level and in body fatness

ABSTRACTPerceived exertion during exercise was studied in 51 physically active and in 19 sedentary men, 41–60 years old, by the use of a numerical scale for rating of perceived exertion (RPE). The subjects, who varied in degree of adiposity, each had two or more characteristics associated with the p

Breathing dry or humid air and exercise-induced asthma during swimming

SummaryRecent studies have shown the relevance of air humidity to the provocation of bronchoconstriction by running. The present study was undertaken to ascertain whether the humid air breathed during swimming could explain the protective effect of swimming on the asthmatic. Nine asthmatic children 9–15 years old swam while inspiring dry (25–35% R. H.) or humid (80–90% R. H.) air administered in a random order, a week separating the two sessions. The exercise challenge was an 8-min tethered swim at a metabolic rate (n

The effects of intermittent warm-up on 7–9 year-old boys

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