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G T Jessup

Publications and source records attributed to G T Jessup.

13 recordsLinked to original sources
PubMed1977

Validity of the W170 test for predicting maximal oxygen intake.

Recent research has related pedalling frequency to perceived exertion, indicating that subjects pedalling at higher frequencies tend to perceive lower levels of exertion. If tests administered at higher pedalling speeds are valid, then more accurate data on extremely low fit individuals might be possible. The purpose of this study was to determine the validity of the Wahlund-Sjostrand W170 test administered at 50 and 80 rpm. Maximal oxygen intake was determined for thirty male volunteer college students using standard open-circuit techniques. W170 tests were administered at 50 and 80 rpm using standard test protocol. The results indicated a differential effect of pedalling speed upon the validity of the W170 tests. Validity coefficients of rxy = 0.73 and rxy = 0.64 were found for the 50 and 80 rpm tests, respectively. Maximal oxygen intake predicted from the W170 test administered at 80 rpm was significantly different from both the criterion maximal oxygen intake and the W170 prediction at 50 rpm. This difference was attributed to a significantly higher heart rate response to 80 rpm tests at the lower workload of 600 kpm/min. It was concluded that more valid W170 tests are attained at the conventional pedalling speed of 50 rpm.

Adult↗
PubMed1977

Effects of exercise on the severity of isoproterenol-induced myocardial infarction.

The effect of exercise on the severity of isoproterenol-induced myocardial infarction was studied in male rats. Ninety-three rats were randomly divided into three groups. The exercise-isoproterenol (E-1) and exercise control (EC) groups exercised daily for thirty days on a treadmill at 1 mph, 2% grade while animals of the sedentary-isoproterenol (S-I) group remained sedentary. Eight animals were assigned to the sedentary control (SC) group which remained sedentary throughout the experimental period. Forty-eight hours after the final exercise period, S-I and E-I animals received a single subcutaneous injection of isoproterenol (250 mg/kg body weight). Animals of the S-I group exhibited significantly (Pp less than 0.05) greater mortality from the effects of isoproterenol than animals of the E-I group. Serum CPK activity for E-I animals was significantly (p less than 0.05) greater than for animals in the S-I and EC groups twenty hours following isoproterenol injection. No statistically significant differences were observed between the two isoproterenol treated groups for severity of the induced lesions, changes in heart weight, or heart weight to body weight ratios. The results indicated that exercise reduced the mortality associated with the effects of large dosages of isoproterenol but had little on the severity of the infarction.

Animals↗