Aerobic capacity of older adults: a training study.

The effects of a four month aerobic conditioning program on heart rate, blood pressure, maximal oxygen consumption (VO2max), and physical work capacity of 55-70 year old sedentary individuals were evaluated. Twenty-eight men and women participated in either 4 months of supervised fast walking or jogging at a prescribed target heart rate or stretching exercises for one hour, three days per week. Gains in VO2max (ml/kg/min) obtained during a Balke maximal treadmill test in aerobic and exercise control subjects were 27% and 9%, respectively. At posttesting subjects in both groups demonstrated improved maximal work rate, increased treadmill time, and experienced lower resting and recovery heart rates, lower resting systolic blood pressure, and fewer premature ventricular depolarizations during exercise testing. In 67 physician-supervised maximal exercise tests, only one subject did not achieve VO2max due to exercise induced arrhythmias. No events of morbidity or mortality occurred as a result of the exercise testing and training. Subjects were contacted 4 years after study participation to determine if they were adhering to an exercise program. Sixty-four percent reported exercising at least 3 days per week in large muscle activities. We conclude that four months of supervised aerobic and nonaerobic exercise training is sufficient to improve aerobic capacity and other indicators of fitness in older, sedentary men and women, and that these previously sedentary people are likely to continue exercising on an individual basis once they have experienced improved physical capacity.

Age and fitness effects on EEG, ERPs, visual sensitivity, and cognition.

Measures of EEG, event-related potentials (ERPs), visual sensitivity, and cognition were obtained from 30 young (20-31 years) and 30 older (50-62 years) healthy men. Age groups were evenly divided between subjects with low and high fitness levels documented by VO2max during a maximal exercise test. Age comparisons revealed that, compared to young adults, the older men had reduced visual sensitivity, delayed ERP latencies, greater homogeneity of EEG activity across recording sites, more positive visual-evoked potential (VEP) amplitude-intensity (A/I) slope, and poorer performance on a battery of neurocognitive tests. The EEG and VEP A/I slope findings are believed to reflect weakened central inhibition for the older men. In general, the measures that differentiated groups on the basis of age were also sensitive to differences in aerobic fitness. Compared to low fit men, the physically active men had shorter ERP latencies, stronger central inhibition, better neurocognitive performance, and better visual sensitivity. We speculate the performance superiority of the physically active men was, at least in part, the result of more oxygen being available for cerebral metabolism.

Cardio-respiratory fitness of young and older active and sedentary men.

Physiological profiles are described for 30 healthy young (20-31 years) and 30 healthy older (50-62 years) men. Half of the individuals in each group reported that during the previous five years they participated frequently in strenuous physical exercises; the other half reported sedentary lifestyles. A treadmill exercise test was used to determine maximal aerobic power (VO2 max). Heart rate and blood pressure were measured during rest, maximal exercise and recovery. The active older men demonstrated significantly lower resting heart rates, lower resting systolic and diastolic blood pressures, higher VO2 max, lower maximal exercise diastolic blood pressure and lower recovery heart rates than the age-matched sedentary men. Compared with the young sedentary men, the older active men had lower resting heart rates and higher VO2 max, walked longer on the treadmill, had lower recovery heart rates and weighed less. Older active men also had higher VO2 max levels than young sedentary men. In summary, physiological profiles of the older active men more closely resembled profiles of active men who were 30 years younger than those of older sedentary men. These results emphasize the range of benefits associated with exercise.

Isokinetic characteristics of the knee in female, professional and university, ballet and modern dancers*.

*Study conducted as part of thesis submitted by R.D.C. in partial fulfillment of the requirements for the degree of Master of Science. The purpose of this investigation was to evaluate isokinetic characteristics of the knee in female, ballet and modern, professional and university dancers in order to evaluate possible differences among the groups. A total of 37 dancers with a mean age of 24.9 years was tested using a Cybex II dynamometer. A multiple analysis of variance (MANOVA) indicated that the ballet dancers had significantly higher H/Q ratios than modern dancers at three speeds (p < 0.024). Post hoc procedures indicated that the professional ballet dancers (PB) had significantly higher H/Q ratios than all other groups at 180 degrees /sec (p < 0.05). Also, although most of these dancers demonstrated normal peak torque/body weight values for knee extension and flexion, specific weaknesses were observed in the force decay rate of the quadriceps curves. It was concluded that these theatrical dancers were not a homogeneous group in terms of certain isokinetic characteristics.J Orthop Sports Phys Ther 1988;9(12):410-418.

A Physiologic Profile Comparing Levels and Styles of Female Dancers.

In brief: A physiologic profile comparing 39 female dancers was undertaken to better understand the factors distinguishing four levels and styles of dance: professional ballet (PB), professional modern, university ballet, and university modern. The PB dancers had significantly lower VO2 max values on the tread-mill as well as lower peak blood lactate levels following the Wingate test for anaerobic capacity than the other dancers. The PB dancers also had a significantly higher isokinetic hamstring-quadriceps ratio than the modern dancers. These findings suggest that physiologic capacity may differ among female dancers according to their levels and styles of dance.

Physical characteristics of patients with herniated intervertebral lumbar discs.

In an attempt to determine whether certain physical characteristics discriminated between people with and without herniated intervertebral lumbar discs, volunteers (N = 40) who were diagnosed as having a herniated lumbar disc were compared to control subjects (N = 40) who had been randomly selected and matched by age and sex. All subjects completed a questionnaire to determine the history of their back injury and a description of their exercise behavior patterns. Body composition was estimated by hydrostatic weighing. Maximum oxygen consumption was predicted using the Astrand-Ryhming nomogram. Strength scores were determined from a battery of cable tensiometer tests. Dependent variables were analyzed using a multiple analysis of variance (MANOVA). Using discriminant analysis, as a post hoc test, predicted maximum oxygen consumption was shown to account for the difference between the groups (P less than .002). The control subjects' values were higher than the patients' values. Subjects' exercise history indicated no differences between the groups relative to the time period preceding the onset of injury (P greater than .05). The exercise activity of patients was significantly reduced after injury (P less than .001). An average of 87 days elapsed between the onset of injury to the date of fitness testing.

An anthropometric estimation of body composition of older men.

This study sought to derive equations for the functions of estimating the body density (Db), lean body weight (LBW), and percentage body fat (PBF) of older men. Hydrostatic weighing was used to determine the criterion measures of 25 older men, 56 to 70 years of age (M = 62.1, SD = 4.2 years). A stepwise multiple regression analysis of these data developed equations for each variable with multiple correlation coefficients and standard error of estimates of the most practical (p less than .001) being: Db = .857, 0.0047 g/ml; LBW = .954, 2.08 kg; PBF = .842, 2.36%, respectively. The accuracy of these results are commensurate with others reported in the literature.

Total lung capacity, residual volume and predicted residual volume in a densitometric study of older men.

Results of investigations using various lung volumes for hydrostatic weighing determinations (HWD) appear to be inconclusive. Often, these lung volumes are predicted and not clinically determined. For this reason, total lung capacity (TLC), a measured residual volume (RV), and a predicted residual volume (PRV) were used during HWDs to compare the techniques. Twenty-five older men, 56 to 70 years (means +/- 62.1 + 4.2 years) performed HWDs at RV (10 trials) and at TLC (3-5 trials). Values for body density and fat free mass were not significantly different between RV and TLC; both values were, however, significantly different from those derived using PRV. There were statistically significant differences (p less than 0.05) between all 3 per cent body fat values but the 1.1 per cent difference between TLC and RV may not be physiologically important. It was concluded that TLC and RV may be used comparably during HWDs, but a PRV may produce significantly different values. Since HWD at TLC is easily performed and circumvents the difficulties associated with the RV technique, it may be the preferred method for older subjects.

Aerobic exercise training and improved neuropsychological function of older individuals.

The effects of a four month aerobic exercise conditioning program on neuropsychological test performance, depression indices, sensory thresholds, and visual acuity of 55-70 year old sedentary individuals were evaluated. Aerobically trained subjects were compared with two age-matched control groups of subjects: those who trained with strength and flexibility exercises and others who were not engaged in a supervised exercise program. The aerobically trained subjects demonstrated significantly greater improvement on the neuropsychological test battery than did either control group. Depression scores, sensory thresholds, and visual acuity were not changed by aerobic exercise. The pattern of results suggests that the effect of aerobic exercise training was on central rather than on peripheral function. We speculate that aerobic exercise promoted increased cerebral metabolic activity with a resultant improvement in neuropsychological test scores.

Physical characteristics of novice and experienced women marathon runners.

The physiological and anthropometric characteristics of 23 non-elite women marathoners were studied. Ten of these women had never run a marathon before (novices) and 13 had run at least one marathon during the previous year (experienced). A comparison of characteristics of these two groups to each other and to elite women marathoners, as reported in the literature, disclosed no significant (p greater than 0.01) among the groups in age, % body fat, body weight, height, lean body mass or HR max. Significant differences (p less than 0.01) were noted, however, in VO2 max (45.8, 51.8, 59.1 ml.kg-1 min-1), VE max (76.3, 94.7, 108.9 L.min-1), and years of training (0.54, 2.06, 4.55 years) with the novice runners having the smallest values, the experienced runners having the next larger values, and the elite runners having the largest values. For our subjects, estimated percentage of body fat did not correlate with finish time, but VO2 max and finish time were significantly related (r = -0.72, p less than 0.01). This suggest that women marathon runners are similar in anthropometric measurements, and that improved performance is associated with higher aerobic capacity and years of training rather than with body dimensions.

Descriptive analysis of quadriceps and hamstrings muscle torque in high school football players*.

The purpose of this study was to establish a range of acceptable torque values for competition in high school football. The results indicated that body weight can be used as an acceptable predictor of lower extremity muscular torque. Therefore, it was concluded that body weight can be utilized to produce an average range of desirable torque values for participation in high school football.J Orthop Sports Phys Ther 1983;5(1):2-6.

Essential Hypertension and Exercise.

In brief: Responses to a questionnaire given to physicians and clinic directors in the Salt Lake City area indicated the current practices in treating essential hypertension. The most common treatment was step-care drug therapy, although some used exercise as a treatment modality. The authors concluded that: (1) the value of exercise in treating hypertension is not completely understood; (2) the undesirable side effects of drug therapy suggest a closer examination of nonpharmacological treatment; (3) borderline or labile hypertensives are often not treated without specific indications; and (4) exercise physiologists might be helpful to physicians who want to use exercise therapy for their hypertensive patients.