Changes In Aerobic Capacity Research Articles

Long term effects of spinal cord transection in Zebrafish: swimming performances, and metabolic properties of the neuromuscular system

This study concerns functional recovery of zebrafish following spinal cord transection. Spinal cords were transected at the level of the 14th vertebra, just rostral to the dorsal fin. Recovery was tested at one month after transection when descending fibers start to regrow across the transection site and at three months after transection when fish perform kick and glide swimming. To estimate the rate of regrowth across the lesion site we analysed the tyrosine hydroxylase (TH) and dorsal 5-hydroxytryptamine (5-HT) systems in distal parts of lesioned cords. Both systems have cell bodies in the brainstem and in control fish TH- and dorsal 5-HT-containing fibers descend to all spinal segments. Swimming performance was studied by subjecting lesioned fish to endurance tests in a swimming tunnel with water flowing at a constant rate of 2 or 4.5 body lengths per second (BL/s). At 2 BL/s slow myotomal muscles are active whereas at 4.5 BL/s fast myotomal muscles are recruited. Control fish endured sustained swimming at both speeds for at least 3 hours. As a measure for the condition of the neuromuscular system in trunk and tail, we analysed aerobic metabolic capacities, assessed by NADH-tetrazolium reductase (NADH-TR) histochemistry of myotomal muscle fibers and spinal lateral neuropil. We found that TH- and dorsal 5-HT-immunoreactive fibers were absent in the entire distal part of lesioned cords at one month but at two months after transection they were present at approximately 6000 microns caudally to the site of the lesion. Thus the rate of outgrowth of these fibers is at least 200 microns per day. Sustained swimming at the slow speed (2 BL/s) could be endured for about 14.4 min at one month and for 23.5 min at two months after transection; there was no further improvement in the period that followed. In contrast, in the 10 weeks following transection, fast swimming (4.5 BL/s) could be endured for about 5 to 6 minutes. A significant improvement was gained in the period of 10 to 12 weeks after transection when fish could endure the high speed for almost 15 min. The aerobic capacity of muscle fibers in distal parts of the body was not strongly affected by the lesion. The only important change in aerobic capacity was observed in the neuropil of distal parts of the cords where, at three months after transection, NADH-TR activity was increased to approximately 150% of control values. On the basis of our findings, we assume that it is not the condition of the neuromuscular system, but rather a deficient co-ordination between proximal and distal body parts of lesioned fish that accounts for the relatively poor performances in endurance tests. Furthermore, differences in timing of improvements in swimming at 2 and 4.5 BL/s indicate that the spinal circuitries serving the slow parts of the neuromuscular system recover at an earlier stage than those serving the fast parts.

Age and cardiac output during cycle exercise in thermoneutral and warm environments.

To determine whether chronological age, independent of changes in aerobic capacity, alters cardiac output (Qc), the central hemodynamic responses to intermittent incremental cycle exercise were studied in two groups of men. Qc was measured at rest and during exercise at 35%, 60%, 75%, and 85% peak aerobic capacity (VO2peak) using a CO2 rebreathing method in seven trained older (65 +/- 2 yr) and eight normally active but untrained young men (26 +/- 1 yr) matched for VO2peak and anthropometric measures. Subjects were tested in both a thermoneutral (22 degrees C) and a warm (36 degrees C) environment to investigate possible differential cardiovascular responses to exercise in the heat. Only subjects with no history of pulmonary, cardiac, neuromuscular, or endocrine disease and a normal electrocardiogram were studied. The older men had significantly lower (P < 0.05) Qc relative to the younger men at intensities greater than 60% VO2peak in both environmental conditions. At these higher intensities, the older men had a significantly higher stroke volume (SV) and lower heart rate (HR) (P < 0.05). A higher arteriovenous oxygen difference ((a-v)O2)) compared with their younger counterparts enabled the older men to exercise at the same absolute intensity, most likely because of training induced changes in left-ventricular performance and oxygen extraction. The addition of an exogenous heat source did not alter the Qc response in either group of men; however, a higher HR (P < 0.05) and smaller SV (P > 0.05) were observed in the young men during exercise in the heat. This may reflect previously reported differences in the skin blood flow response of VO2peak-matched young and older men during exercise. It is suggested that endurance trained older men can enhance left-ventricular performance to augment SV, but not sufficiently to maintain Qc in light of an attenuated HR response during exercise at intensities above 60% VO2peak.

Role of aerobic capacity and body mass index in the age-associated decline in heart rate variability

The extent to which age-associated changes in aerobic capacity and body composition modulate the age-associated decline in heart rate variability (HRV) is unknown. We therefore measured HRV, peak O2 consumption (VO2peak) during treadmill testing, and relative weight (body mass index; BMI) in 164 healthy normotensive adults (75 men, age 20-87 yr) from the Baltimore Longitudinal Study on Aging. Two components of HRV, respiratory sinus arrhythmia (RSA; 0.12-0.40 Hz) and 0.10-Hz variability (0.06-0.10 Hz), were extracted from 8-min electrocardiogram recordings in the supine, seated, and standing postures. RSA, 0.10-Hz variability, and VO2peak varied inversely with age; BMI was unrelated to age. Age contributed 15.5-21.1% independent variance to RSA and 13.2-17.3% independent variance to 0.10-Hz HRV. VO2peak did not contribute significantly to RSA or 0.10-Hz HRV beyond the effect of age in any posture. There were no consistent independent contributions of BMI to HRV. Thus, in this population-based sample, age-associated changes in aerobic capacity and relative body weight do not provide the primary explanation for the decline in HRV observed with advancing age.

CHANGES IN NOCTURNAL CATECHOLAMINE EXCRETION AND AEROBIC CAPACITY OF JAPANESE KENDO FENCERS DURING WINTER TRAINING 944

Kendo fencing is one of the popular Budo in Japan. Kendo fencers usually carry out a high intensity training camp in the cold winter. The camp is thought to be effective both in the cultivation of the mind and the improvement of physical fitness. The purpose of this study was to investigate the changes in nocturnal urinary catecholamines excretion and aerobic capacity during the camp accomplished in college kendo fencers. Training in the camp was performed for 2 hours from 5:00 to 7:00 am., and the camp was continued for 10 days in January. We studied the physical condition of 5 female college kendo fencers. They were instructed to record their physical condition, such as fatigue, muscle soreness, etc. with 7-point rating scale numbered from 1(very bad) to 7 (very good) every day throughout the camp. We measured nocturnal urinary catecholamines excretion on the first and the final days of the camp, and evaluated their aerobic capacity (VO2max) before and 3 days after the camp using multistage fitness test. Measurement of resting blood creatine kinase (CK) activity before a training was performed on the first, the middle, and the final days of the camp. Subjective physical condition was significantly decreased on the 2nd day (mean±SD; 3.5±1.4, p<0.01) from the initial level before the camp(4.7±1.7), and thereafter did not return until the final day. Compared with the first day of the camp, resting blood CK activity was significantly increased on the middle day (131.3±43.0%, p<0.05), and was remained at higher level on the final day (126.4±124.4%, n.s.). Nocturnal urinary catecholamines excretion were decreased on the final day(Δadrenaline; 0.632±4.979μg/min. n.s., Δnoradrenaline; 14.5±45.3 μg/min, n.s., Δdopamine; 0.220±0.344μg/min, n.s.) compared with the first day. and aerobic capacity was also declined 3 days after the camp (2.8±6.9%, n.s.). In addition, there were significant correlations between changes in nocturnal urinary catecholamines excretion and aerobic capacity (vs adrenaline; r=-0.940, p<0.05, vs noradrenaline; r=-0.910, p<0.05). Change in basal sympathetic activity during the high intensity training camp might cause changes in aerobic capacity and subjective condition during the traditional high intensity training camp of Japanese kendo fencing.

Moderate intermittent doses of exercise improves insulin and insulin/glucose in overweight females 899

Despres et al. (Am J Physiol, 1991) have demonstrated that changes in metabolic fitness, including fasting insulin, glucose, and insulin/glucose may occur independent of changes in aerobic capacity in obese females who participated in an aggressive exercise program. Since most adults will not exercise aggressively (Powell, Ann Rev Pub Health, 1988) our purpose was to explore the possibility that long-term, moderate, intermittent exercise may reduce fasting insulin, glucose, and insulin/glucose. 12 females% fat = 40.6± 8.8 exercised at a moderate intensity which was 50-65% of the heart rate reserve determined from a maximal exercise test. Walking was performed in 10 min bouts, 3X/day, 5d/week for 32 weeks at the individual worksite. Total energy expenditure of exercise estimated from Caltrac was 137676 ± 30756 kJ. Subsequent to training, there were no changes in aerobic capacity, body composition (BC), or fasting insulin and glucose values. We then separated the subjects into “responders and non-responders” based on a 7% increase in aerobic capacity. Nine subjects met the criteria of responders and showed no significant change in BC or glucose. However, there were significant decreases in fasting insulin and insulin/glucose of 7.0± 6.9 mcu/ml p<0.01 and 0.09±0.09 p<0.02, respectively. The correlations between the change in aerobic capacity and insulin and insulin/glucose were 0.17 and 0.14, respectively (NS). No changes in BC or insulin, glucose and insulin/glucose were shown for the 3 non-responders. This seems to suggest a threshold effect for exercise rather than a dose response relationship to the improvement of insulin and insulin/glucose. Moderate intermittent exercise which improves aerobic capacity may provide enough stimulus to invoke improvements in insulin and insulin/glucose in moderately obese females.

EFFECTS OF 12 WEEKS OF STATIONARY CYCLING, TREADMILL WALKING, STEPPING, OR SIMULATED CROSS-COUNTRY SKIING ON AEROBIC CAPACITY AND BODY COMPOSITION 77

One hundred and two (48 M and 54 F) apparently healthy volunteers between the ages of 20 and 50 years were randomized equally to one of five groups: stepping (S), treadmill walking (TM), simulated cross-country skiing (XC), stationary cycling (B), or control (C). Subjects in the exercise groups trained 3X/week for 12 weeks. Exercise HRs averaged 155 bpm (84%) of HRmax and were not different between groups. Subjects were tested before and after the study for body composition (hydrostatic weighing and anthropometrics) and aerobic capacity (VO2max). The VO2 max tests for each group were conducted on the specific training modality used during the study. Three day food records were also analyzed pre and posttesting. Data were analyzed with repeated measures ANOVA and Tukeys' post-hoc tests. There were no differences in the responses of males and females over the training period. Selected combined results are presented below for changes in body weight (kg),% body fat, waist girth (cm), and VO2max (ml/kg/min).Table There were no differences in the responses between any of the training groups, and changes were generally significantly different than C. Analysis of the food records found similar reductions in caloric intake (approximately 252 calories/day) for all of the training groups. Results of this study found that when subjects trained at the same exercise intensity and made similar reductions in caloric intake, changes in aerobic capacity and body composition were similar regardless of the exercise modality.

A COMPARISON OF THE PHYSIOLOGIC RESPONSES WHEN EXERCISING ON FOUR COMMON EXERCISE MODALITIES AT A SELF-SELECTED OR SELF-PREFERRED EXERCISE INTENSITY 80

Rather than forcing individuals to exercise at a certain target heart rate, the current trend in exercise prescription is to let people exercise at a“self-selected” or “self-preferred” exercise intensity. The thought is that this represents a more real world situation and one which may enhance exercise adherence, since people are exercising at a level which is more comfortable for them. The purpose of this study was to try and determine if the self-preferred exercise intensity differed between four common exercise modalities (ST=stepping, BK=stationary cycling, TM=treadmill walking, XC=simulated cross-country skiing). Sixteen apparently healthy volunteers (8 M and 8 F) between the ages of 30 and 62 years served as subjects. After given ample practice time (at least 5 practice sessions per machine), subjects performed 20 minutes of steady state exercise on each modality, in random order, at an intensity of their own choosing. Each session was preceded by a 5 minute warm-up. HR, RPE, and VO2 were recorded every 2 minutes during each exercise bout. Results for M and F were similar and summary data are presented below. Table It was found that subjects exercised at a higher HR and VO2 and burned more calories on XC compared to the other exercise modalities, which is probably related to the greater muscle mass involved in the exercises compared. Theoretically, if individuals were to train under these conditions, XC would result in the greatest changes in aerobic capacity and body composition.

Changes in aerobic capacity and coronary risk factors during long-term exercise training in women with ischemic heart disease: a 36-month follow-up.

We evaluated the time course of alteration in aerobic capacity and coronary risk factors associated with a 36-month exercise program in women with ischemic heart disease (IHD). Twenty-one patients participated in supervised exercise and home-based exercise programs for 36 months. However, of all patients, 11 patients completed the entire program. Oxygen uptake corresponding to lactate threshold (VO2LT), peak oxygen uptake (VO2peak), percent of body fat (%BF), systolic (BPs) and diastolic (BPd) blood pressure, total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC) and triglycerides (TG) were assessed before and 4, 8, 12, 24, and 36 months after exercise. The intensity of exercise was set at individually determined LT, i.e., 60 to 70% VO2peak. The daily amount of exercise during 36 months averaged 24.0 +/- 11.4 minutes per day. During the course of exercise program, VO2LT, VO2peak, BPs, BPd, and TG improved significantly at month 4. Although %BF decreased significantly at month 8 to 12, it tended to return to the initial level at month 36. On the other hand, a significant increase in HDLC was found at month 24 and improved state of HDLC remained unchanged thereafter. No changes were found in TC and LDLC. These results suggest that most of the beneficial effects of exercise on aerobic capacity and coronary risk factors in women with IHD are obtained within 4-8 months, with some further improvement seen with continued exercise up to 24 months.

Relationship between Habitual Physical Activity and Aerobic Fitness in Adolescents

This review summarizes the research relating physical activity to aerobic fitness among adolescents. A brief description of commonly used physical activity and aerobic fitness measures is presented, followed by an interpretation of the literature that suggests a small to moderate relationship between physical activity and aerobic fitness in this population (typical correlation of .16-17). Dose-response data are lacking, which makes it difficult to offer definitive conclusions concerning the amount of physical activity necessary to elicit change in aerobic capacity. Nevertheless, recommendations about the type, amount, and quality of physical activity for adolescents are presented. Recommendations are based on a summary of the research data on daily physical activity and aerobic fitness in adolescents. Further research is needed to investigate the association between habitual physical activity and aerobic fitness in adolescents where the a priori goal is to identify a threshold of daily physical activity necessary for an aerobic benefit associated with enhanced health.

ステップテストを用いた持久性能力の加齢変化の研究

The purpose of this study was to develop a step-test in order to evaluate age-related change in aerobic capacity. A total of 149 healthy men of age through 18 to 83 yrs ascended and descended a single step of 0.2 m height in time to a metronome. The step rate increased step-wise through three stages, each of 3 min duration; 15, 20 and 25 (step/min) for subjects aged 59 or less, and 10, 15, and 20 (step/min) for those age 60 and over. Using the linear relationship between load and heart rate, physical work capacity (PWC, watt/kg) was estimated as the work load with maximum heart rate predicted by age (220-age). In the elderly group (n = 34), heart rate at the end of the last stage was within 60-80% of the maximum heart rate for 25 subjects, and more than 80% for the other 9 subjects. No risky arrhythmia or significant ST change on ECG appeared in any subject. A retest of the step-test for 16 elderly subjects showed its repeatability and a linear relationship between heart rate and oxygen consumption. The results suggested that the step-test was applicable to the elderly in regard to appropriate work load and safety. The PWC significantly declined with aging (r = 0.52, p < 0.001). Relative aerobic capacity, taking that at age 20 as 100%, was 60% and 53% for subjects aged 60 and 70, respectively, which was in good agreement with available reports which measured oxygen consumption directly.

Effects of exercise training on cardiovascular function and plasma lipid, lipoprotein, and apolipoprotein concentrations in premenopausal and postmenopausal women.

This study examined the effects of aerobic exercise on lipid levels in premenopausal and postmenopausal women. Fifty healthy middle-aged women (mean age, 50 years) were randomly assigned to 12 weeks of either aerobic exercise (walking and jogging) or nonaerobic strength exercise (circuit Nautilus training). Concentrations of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and very low density lipoprotein cholesterol were assessed, along with apolipoprotein (apo) A-I, apo A-II, apo B, and triglycerides. To document changes in aerobic capacity, maximum treadmill testing was performed with expired-gas analysis before and after the exercise program. Aerobic exercise was associated with an 18% improvement in peak VO2. Women in the aerobic group had an increased VO2, from 26.7 to 31.4 ml/kg/min (p less than 0.0001), while the VO2 of the women in the strength training group did not change (25.8 ml/kg/min before and after). There were no differential changes in lipid levels because all subjects experienced slight reductions in high density lipoprotein cholesterol and total cholesterol and increases in apo A-I and the apo A-I to apo B ratio. There was a tendency for the aerobic group to exhibit lower levels of apo A-II and a greater apo A-I to apo A-II ratio, however. We conclude that premenopausal and postmenopausal women experience similar changes in aerobic capacity and lipid levels with exercise and that the short-term effects of aerobic and nonaerobic exercise on lipid profiles are generally comparable.

Effects of exercise training on high density lipoproteins and apolipoprotein A-I in old and young men

Although exercise training has been demonstrated to improve lipid profiles in young and middle-aged subjects, the response in training in the elderly has received little attention. In this study, we assessed and compared the changes in aerobic capacity, lipid profiles, and body composition in young (Y, 31.9 ± 5.5 years; n = 18) and older (O, 65.1 ± 6.1 years; n = 10) subjects in response to similar 3-month exercise training programs (80% to 85% of heart rate reserve, three times per week). We hypothesized that the responses would be qualitatively similar for the two groups, although the absolute quantitative response might be somewhat less in the elderly. The two groups were quite similar at baseline for percent body fat (Y, 30.1% ± 7.2% v O, 30.3% ± 4.7%; P = NS) and maximal aerobic capacity (Y, 36.8 ± 8.1 v O, 36.3 ± 8.3 mL/kg/min; P = NS). In addition, there were no significant differences in the baseline lipid profiles between the groups. After training, the improvements in body composition were similar, with both groups losing similar amounts of fat (Y, 2.86% ± 3.14% v O, −2.85% ± 1.78%) and neither group significantly changing their fat-free mass. Maximal aerobic capacity improved in both groups, but the increment was greater in the young (18% v 10%, P < .05). HDL-cholesterol (+6%, P < .01) and apolipoprotein A-I (+6%, P < .01) concentrations increased significantly only in the young. These increments, however, were not different from those observed in the older subjects (+7% and +4%, respectively). Using multiple-regression models, at baseline HDL-cholesterol concentration was independently related to both maximal aerobic capacity ( r = .57, P = .01) and apolipoprotein A-I concentration ( r = .62, P < .001), but following training the change in HDL-cholesterol was related only to the change in apolipoprotein A-I. We concluded that, despite a lower increment in maximal aerobic capacity in the older subjects, the improvements in body composition and lipid profiles after a 3-month training program were similar in young and old subjects.

Varied intensities of training, predicted maximum oxygen uptake and the minimum threshold hypothesis.

In this study, 24 sedentary first-year male university students aged 17 to 24 yr. were assigned to one of four groups. Three of the groups underwent a 6-wk. training program consisting of a 30-min. bicycle ergometer ride, three times per week. A fourth group acted as a control. The experimental groups trained at workload intensities corresponding to predetermined heart rates of 125, 140, and 155 bpm, respectively. Analysis of scores indicated that changes in aerobic capacity occurred only if the intensity of training exceeded a minimal level. Essentially, these results replicated data from other studies.

Direct and indirect assessment of skeletal muscle blood flow in chronic congestive heart failure

In patients with chronic congestive heart failure (CHF), skeletal muscle blood flow can be measured directly by the continuous thermodilution technique and by the xenon133 clearance method. The continuous thermodilution technique requires retrograde catheterization of the femoral vein and, thus, cannot be repeated conveniently in patients during evaluation of pharmacologic interventions. The xenon133 clearance, which requires only an intramuscular injection, allows repeated determination of skeletal muscle blood flow. In patients with severe CHF, a fixed capacity of the skeletal muscle vasculature to dilate appears to limit maximal exercise performance. Moreover, the changes in peak skeletal muscle blood flow noted during long-term administration of captopril, an angiotensin-converting enzyme inhibitor, appears to correlate with the changes in aerobic capacity. In patients with CHF, resting supine deep femoral vein oxygen content can be used as an indirect measurement of resting skeletal muscle blood flow. The absence of a steady state complicates the determination of peak skeletal muscle blood flow reached during graded bicycle or treadmill exercise in patients with chronic CHF. Indirect assessments of skeletal muscle blood flow and metabolism during exercise performed at submaximal work loads are currently developed in patients with chronic CHF.

Metamorphosis of the American eel, Anguilla rostrata LeSeur: III. Contractile characteristics of skeletal muscle.

Previous work has suggested a common migratory strategy among fishes may involve changes in recruitment pattern of skeletal muscle types, allowing fast muscle to function continuously. In this study no evidence was found for changes in adenine nucleotide metabolism, thought to be important in fatigued muscle, with metamorphosis from the nonmigratory yellow to migratory silver eel in either slow or fast muscle tissue. Myofibrillar ATPase activity was found to be lower than reported values for other teleosts, around 0.075 and 0.17 microM inorganic phosphate mg-1 min-1 for slow and fast muscle, respectively. No change was found in the Ca++-kinetics of the enzyme within either muscle type. Likewise, no change in the contractile performance of fast muscle was evident, arguing against changes in activity pattern. In contrast to mammalian endurance exercise training where major changes in aerobic capacity occur in fast muscle, migratory pre-adaptation in eel appears to be restricted to changes in slow muscle performance. A displacement of the slow muscle force-velocity curve to the right upon metamorphosis results in 30% increase in the tension developed at maximal power output from 2.4 to 3.2 N cm-2. The difference in migratory potential between yellow and silver eels was shown previously to involve an increased aerobic capacity. The change in contractile characteristics may further improve endurance by permitting a portion of the tissue to periodically replenish endogenous energy stores.

Modification of Type A behavior through aerobic exercise

This psychophysiological evaluation of an aerobic exercise program examined specifically whether aerobic training modified Pattern A for those individuals at behavioral risk for developing coronary heart disease, i.e., young Type A individuals. At pretest and posttest of this secondary prevention study, Type A and Type B subjects were assessed in three conditions: aerobic exercise program, nonaerobic activity (Aikido, a martial art) control, and notreatment control. After 10 weeks, Type A but not Type B subjects exhibited lower Pattern A behavior in the aerobic program than in control conditions. Average workout pulse rates and differentially reliable increases in aerobic capacity indicated that aerobic training was indeed aerobic, whereas aikido activity was not. Even though selected nonaerobic factors, such as locus of control and group participation, did not mediate the Pattern A decrease for Type A's when comparing aikido and aerobic conditions, changes in aerobic capacity may have been the mediator. Generalizability of the results and implications for theoretical development and clinical intervention are discussed.

Endurance training in humans: aerobic capacity and structure of skeletal muscle.

The adaptation of muscle structure, power output, and mass-specific rate of maximal O2 consumption (VO2max/Mb) with endurance training on bicycle ergometers was studied for five male and five female subjects. Biopsies of vastus lateralis muscle and VO2max determinations were made at the start and end of 6 wk of training. The power output maintained on the ergometer daily for 30 min was adjusted to achieve a heart rate exceeding 85% of the maximum for two-thirds of the training session. It is proposed that the observed preferential proliferation of subsarcolemmal vs. interfibrillar mitochondria and the increase in intracellular lipid deposits are two possible mechanisms by which muscle cells adapt to an increased use of fat as a fuel. The relative increase of VO2max/Mb (14%) with training was found to be smaller by more than twofold than the relative increase in maximal maintained power (33%) and the relative change in the volume density of total mitochondria (+40%). However, the calculated VO2 required at an efficiency of 0.25 to produce the observed mass-specific increase in maximal maintained power matched the actual increase in VO2max/Mb (8.0 and 6.5 ml O2 X min-1 X kg-1, respectively). These results indicate that despite disparate relative changes the absolute change in aerobic capacity at the local level (maintained power) can account for the increase in aerobic capacity observed at the general level (VO2max).

Physiological Alterations in 7- to 9-Year-Old Boys following a Season of Competitive Wrestling

Abstract Muscular and aerobic capacity changes resulting from three months of wrestling training were examined in a group of normally active 7- to 9-year-old boys (N = 23) who competed in an intramural league tournament. A nontraining group of twenty-two boys of similar age, height, and weight served as control subjects, and were studied during the same period of time. The subjects were measured for body dimensions and skinfolds, and were given measures of back lift, leg press, and arm endurance (dips and chins). They were also measured for [Vdot]E max, [Vdot]O 2 max, and HR max employing a progressive treadmill protocol. Results of ANCOVA analyses indicated that (1) the mean improvements in [Vdot]E max (2.93 1·min −1 ) and in [Vdot]O 2 max (+ 6.6 ml·kg −1 ·min −1 ) were not significantly greater than control (p > .05), nor was HR max; (2) arm endurance improved significantly over control (p .05); (3) no significant change...

Exercise, changes in aerobic capacity, and changes in self-perceptions: An experimental investigation

Subjects in an exercise training condition participated in a 10-week aerobic exercise class, whereas subjects in waiting-list control and independent control conditions did not. The results indicated that subjects in the training condition evidenced reliably greater improvements in physical fitness (aerobic capacity) and reported reliably greater improvements in their abilities and confidence in both the physical area (e.g., ability to run distances) and nonphysical area (e.g., frustration tolerance) than did subjects in the control conditions. On the other hand, improvements in physical fitness were not related to reported improvements in abilities and confidence. These findings are of interest because they indicate that some of the important personal changes that are associated with physical fitness training are not due to changes in fitness, but appear to be due to other factors (e.g., group participation and expectancies).

Longitudinal variations in maximal oxygen intake with age and activity.

Longitudinal variations in maximal oxygen intake with age and activity.