ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

ABSTRACT. The reported decline in Physical Working Capacity (PWC) max is from 9–15 percent during the ages of 45 to 55 years. The use of vigorous physical activity to prevent this decline and to possibly protect against fatal myocardial infarction has been suggested. The purpose of this study was to investigate the effect of an endurance type exercise program on the maximal PWC of middle-aged men during a 10 year span. Sixteen men, initially 32–56 years (M-44.6), were trained with running or swimming at an intensity above 60 percent of Vo2 max during a 10 year period. The average weekly running distance was 15 miles (25 km). The criterion for PWC was directly measured Vo2 using the Douglas Bag/Scholander technique. No changes were observed in body weight, resting heart rate (HR), or rest-, ing blood pressure (BP). Maximal HR declined 7 beats per minute in 10 years. Pulmonary ventilation (STPD) increased approximately 18 percent. Mean Vo2 max was essentially unchanged, 3.376 and 3.303 1/min STPD. Vo2 max related to body weight was 43.7 initially and 44.4 ml/min-kg after 10 years. It was concluded that the usual 9–15 percent decline in PWC or Vo2 max from age 45 to 55 years can he forestalled by regular endurance exercise. The results may have implications for protecting against heart attacks.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The energy cost of level walking and level and grade running was determined in 7 active women with max &OV0312;o2= 50.7 ml/kg min. Speeds investigated were 4 to 8 km/hr walking and 8 to 145 km/hr running. The validity coefficients of several procedures for estimating energy expenditure during locomotion [4 for running (6)(11)(16)(17); 3 for walking (6)(12)(17)] were determined. Correlation coefficients between actual and predicted values were 0.949 to 0.951 with standard errors of estimate 0.79 to 0.80 keal/kg hour for walking and 0.856 to 0.975 with standard errors of estimate −0.40 to 0.60 kcal/ kg-hour for running. &OV0312;o2and kcal energy cost values were similar to those previously reported on men at equivalent walking. and running speeds. Efficiency of running based on lift work done was about 25%. Lift work for women was slightly less than values previously reported for men at walking but was slightly more at running. These differences did not appear to have a significant effect on energy expenditure.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Treadmill and track running comparisons were made on eight track athletes. Oxygen uptake (&OV0312;o2) during steady-state and maximum aerobic power (&OV0312;o2max) were measured in a discrete series of three speeds, and at maximal effort. Running speeds were always in sequence from slowest to fastest. Expired air was collected from the runner by the Douglas-bag method, and analyzed by the Lloyd-Haldane technique. Neither &OV0312;o2max nor aerobic requirements of running were significantly different in track and treadmill determinations. There were several correlations: 1) &OV0312;o2max with body weight (r = .83 P < .02), 2) treadmill and track determinations of &OV0312;o2max (r = .95, P < .01) and 3) &OV0312;o2ml/kg with running velocity m/min (r = .91, P < .01) where the regression was linear and may be represented by the equation Y = 5.36 -r 0.172X, where Syx = 2.7 ml02/kg. It is concluded that treadmill determinations of oxygen uptake may be validly applied to track running in calm air within the range of 180 … 260 m/min.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Ten moderately active male volunteers, age 19–30 years, completed one month of training on either a kayak or a bicycle ergometer (five men in each group). The men completed sixteen 30 minute sessions of continuous work at an intensity which maintained their HR within 85–90% of its maximum, as previously determined on the kayak ergometer. After this training period the kayak group demonstrated significant decreases in &OV0312;o2, &OV0312;E, HR and blood lactate in submaximal kayak ergometer work and a significant increase in &OV0312;o2during maximal kayak ergometer work. These changes contributed to a significantly higher maximal kayaking work output. The bicycle-trained group did not make any of these improvements on the kayak ergometer. However in their last training session on the bicycle ergometer they were able to work at a higher submaximal load while maintaining the same heart rate as in the first training session. It was concluded that the circulatory and metabolic adjustments to kayak work are greater with kayak training than with bicycle training.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The cardiopulmonary capacities of 15 selected 10 year old ice hockey players were determined during a discontinuous steady-state bicycle ergometer test. During the test, heart rates, minute ventilation and oxygen uptake were monitored and the peak values at maximal capacity were recorded. Blood was collected From the median cubital vein after each maximal exercise for lactate analysis. These boys represented a select group of highly successful young hockey players. They had been involved in organized hockey for a mean of 4.4 years, 2.9 of which had been spent in a competitive league. The team has ranked 3rd in the Ontario Championships. The maximal oxygen uptake was 50.6 ml/kg-min, a value much higher than reported for healthy inactive boys and close to values reported for young athletes in other sports. Mean maximal minute ventilation reached 64.5 1/min (1.84 l/kg-min). The tests on these athletes were carried out on two separate occasions, 48 hours apart. The test-retest correlations for Vo2max was high (r = 0.81). Only the reliability of the lactate determinations was low (r = 0.24). None of the differences between the mean values for the measurements made at the first and second exercise tests were significant.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Heart rate (HR), total electromechanical systole (Q-S2). left ventricular ejection time (LVET), pre-ejection period (PEP), and diastole (D) were compared in 350 former athletes and 156 non-athletes, age 27–74. The two cohorts had been equated according to habitual leisure time physical activity. Former athletes exhibited significantly longer Q-S2and PEP at rest, and significantly lower HR and lengthened Q-S2, LVET, PEP, and D at one minute following a standard two minute step test (< 0.05). Significant differences were observed between athletes and non-athletes in the light and moderate activity categories. There were no significant differences between former athletes and non-athletes currently engaged in strenuous leisure time physical activity. Comparisons were made among the three levels of habitual leisure time physical activity within each group and revealed that HR was lower and Q-S2, LVET, PEP, and D were longer at rest and following exercise as the level of physical activity increased. There were more significant differences among former athletes than among non-athletes. Most of these differences were between light to moderate and light to strenuous levels of activity. The evidence suggests an advantage in myocardial function among former athletes compared to their non-athlete counterparts.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The relationship between serum testosterone (ST), body composition, and static strength was studied in 26 college females and 16 male college football players. In addition, the transient effect of weight training on ST was studied in 10 college males (5 skilled and 5 unskilled weight trainers), 12 male high school students, and 5 female college students. ST, measured by radioimmunoassay, ranged from 333.7 to 848.1 ng/100 ml in males, and from 32.8 to 121,5 ng/100 ml in females. The high school subjects had significantly lower levels of ST. Correlations between serum testosterone, body composition (measured by densitometry), and static strength, (grip and backlift) were nonsignificant in males and females, Comparison of subjects with the highest and lowest levels of testosterone within each sex showed no significant differences in strength or body composition. Serum testosterone increased 111.4±96.1 ng/100 ml (x± sx) following a weight training session in the male college group, but failed to increase in the college females or high school males. There were no significant differences in testosterone increases between the skilled and unskilled male weight trainers. Maximal exertion may be necessary for an increase in serum testosterone to occur. Lack of an increase in testosterone by high school males or college females may have been due to a sub-maximal effort during the weight training exercise.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Eight male university students served as subjects in nn investigation desibmed to develop strength using two different muscle training routines over a six week period. The subjects trained tlie arm and leg on one side of their bodies using concentric contractions and the arm and leg on the opposite side of their bodies with identical exercises using eccentric contractions. Concentric movements were against n resistance 80% of one-repetition-maximum (l-Rm) for 10 repetitions and two sets; eccentric movements were against a force of 120% of concentric 1-RM for 6 repetitions and two sets. Both routines produced significant gains in strength in all subjects, but neither training procedure produced dynamic or static strength gains significantly different from tlie other. Subjective evaluations by the subjects indicated that the eccentric training movements were easier to perform than the concentric training movements.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Four hundred patients, average age 35 attended for treatment of strains to calf muscles. There was an average delay of 8 days before presenting. The treatment involved several repetitions of a routine involving ice or short wave for pain relief, passive stretching, ultra sound and exercises firstly for the antagonists and then the injured muscle in that order. Quadriceps exercises and correct walking were performed to ensure fitness for sport after cure. The average treatment time was 6 days. Prevention of disability was aided by early treatment, stretching before activity and exercises to increase strength in the calf. The recurrence rate was 1%.

ISSN:0025-7990    

出版商:OVID    

年代:1976

数据来源: OVID