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PubMed2001

Brief intense exercise followed by passive recovery modifies the pattern of fuel use in humans during subsequent sustained intermittent exercise.

The role of work period duration as the principal factor influencing carbohydrate metabolism during intermittent exercise has been investigated. Fuel oxidation rates and muscle glycogen and free carnitine content were compared between two protocols of sustained intermittent intense exercise with identical treadmill speed and total work duration. In the first experiment subjects (n=6) completed 40 min of intermittent treadmill running involving a work : recovery cycle of 6 : 9 s or 24 : 36 s on separate days. With 24 : 36 s exercise a higher rate of carbohydrate oxidation approached significance (P=0.057), whilst fat oxidation rate was lower (P < or = 0.01) and plasma lactate concentration higher (P < or = 0.01). Muscle glycogen was lower post-exercise with 24 : 36 s (P < or = 0.05). Muscle free carnitine decreased (P < or = 0.05), but there was no difference between protocols. In the second experiment a separate group of subjects (n=5) repeated the intermittent exercise protocols with the addition of a 10-min bout of intense exercise, followed by 43 +/- 5 min passive recovery, prior to sustained (40 min) intermittent exercise. For this experiment the difference in fuel use observed previously between 6 : 9 s and 24 : 36 s was abolished. Carbohydrate and fat oxidation, plasma lactate and muscle glycogen levels were similar in 6 : 9 s and 24 : 36 s. When compared with the first experiment, this result was because of reduced carbohydrate oxidation in 24 : 36 s (P < or = 0.05). There was no difference, and no change, in muscle free carnitine between protocols. A 10-min bout of intense exercise, followed by 43 +/- 5 min of passive recovery, substantially modifies fuel use during subsequent intermittent intense exercise.

Adult↗

PubMed2004

The effects of a low-to-moderate intensity pre-conditioning exercise programme linked with exercise counselling for sedentary haemodialysis patients in The Netherlands: results of a randomized clinical trial.

OBJECTIVES: The purpose of this study is to determine whether a low-to-moderate intensity pre-conditioning exercise programme linked with exercise counselling could improve behavioural change, physical fitness, physiological condition and health-related quality of life of sedentary haemodialysis patients in The Netherlands. METHODS: Ninety-six haemodialysis patients of the Groningen Dialysis Center were randomized into an exercise group (n = 53) and a control group (n = 43). The exercise programme consists of cycling during dialysis together with a pre-dialysis strength training programme lasting 12 weeks. The intensity of the exercise programme is condition level 12-16 according to the rate of perceived exertion (RPE). Motivational interviewing techniques were used for exercise counselling. Before and after the intervention, both groups were tested on behavioural change and physical fitness components such as reaction time, manual dexterity, lower extremity muscle strength and VO2 peak. Physiological conditions such as weight, blood pressure, haemoglobin and haematocrit values, cholesterol and Kt/V were obtained from the medical records. Health-related quality of life assessment included RAND-36 scores, symptoms and depression. RESULTS: A group x time analysis with MANOVA (repeated measures) demonstrates that participation in a low-to-moderate intensity exercise programme linked with exercise counselling yields a significant increase in behavioural change, reaction time, lower extremity muscle strength, Kt/V and three components of quality of life, and no significant effects in the control group. CONCLUSION: Participating in a low-to-moderate intensity pre-conditioning exercise programme showed beneficial effects on behavioural change, physical fitness, physiological conditions and health-related quality of life.

Adult↗

PubMed1995

Effects of recombinant human erythropoietin and exercise training on exercise capacity in hemodialysis patients.

The effects of recombinant human erythropoietin (rHuEPO) and exercise training on exercise capacity were evaluated in 20 hemodialysis patients. After improvement of anemia by rHuEPO (Phase I), patients were divided into 2 groups. Group 1, 10 patients, was placed in a 3-month exercise training program. Group 2, 10 patients, served as a control group (Phase 2). A symptom-limited exercise tolerance test was performed at the start of Phase 1 and before and after Phase 2. Hemoglobin (Hb) values were kept constant throughout Phase 2. In Phase 1, maximum workloads (62.0 +/- 19.1 to 76.5 +/- 25.6 W, p < 0.001), maximum O2 uptake (VO2max) (18.7 +/- 3.5 to 2.2 +/- 5.9 ml/min/kg, p < 0.01), and VO2 at anaerobic threshold (AT) (VO2AT) (8.5 +/- 2.1 to 10.2 +/- 2.9 ml/min/kg, p < 0.01) were all improved by rHuEPO. However, in Phase 2, despite unchanged Hb values and maximum workloads, VO2max (20.7 +/- 4.6 to 17.6 +/- 2.6 ml/min/kg, p < 0.05) and VO2AT (10.6 +/- 1.4 to 9.5 +/- 1.8, ml/min/kg p < 0.05) were decreased in Group 2. However, in Group 1, maximum workloads (66.7 +/- 8.2 to 81.7 +/- 7.5 W, p < 0.01) were improved, and VO2max and VO2AT were not decreased significantly in the same period. Exercise training in rHuEPO-treated hemodialysis patients resulted in an improved aerobic exercise capacity, whereas those without exercise training did not have increased capacity. Throughout the study, O2 uptakes were lower than those of nonrenal anemic patients who had similar Hb values. Maximum lactate values also remained low. In conclusion, improvement in the exercise capacity in hemodialysis patients treated with rHuEPO was minimal. Some defects were suggested in the aerobic energy production system in skeletal muscle of dialysis patients. Anemia-improved patients should participate in incremental physical activity to maintain an improved exercise capacity.

Adult↗

PubMed2005

Excess post-exercise oxygen consumption following continuous and interval cycling exercise.

The purpose of this investigation was to examine the effect of interval (INT) and continuous (CON) cycle exercise on excess post-exercise oxygen consumption (EPOC). Twelve males first completed a graded exercise test for VO2max and then the two exercise challenges in random order on separate days approximately 1 wk apart. The INT challenge consisted of seven 2 min work intervals at 90% VO2max, each followed by 3 min of relief at 30% VO2max. The CON exercise consisted of 30 to 32 min of continuous cycling at 65% VO2max. Gas exchange and heart rate (HR) were measured for 30 min before, during, and for 2 h post-exercise. Three methods were used to analyze post-exercise oxygen consumption and all produced similar results. There were no significant differences in either the magnitude or duration of EPOC between the CON and INT protocols. HR, however, was higher (P < 0.05) while respiratory exchange ratio (RER) was lower (P < 0.05) following INT. These results indicate that when total work was similar, the magnitude and duration of EPOC were similar following CON or INT exercise. The differences in HR and RER during recovery suggest differential physiological responses to the exercise challenges.

Adult↗

PubMed1994

Effects of pregnancy and chronic exercise on respiratory responses to graded exercise.

Effects of cycle ergometer conditioning (heart rate 143 +/- 2 beats/min, 25 min/session, 3 sessions/wk) during the second and third trimesters of pregnancy were studied in 18 healthy previously sedentary women. A nonexercising control group (n = 9) was also studied. Graded exercise tests were conducted for both groups at approximately 17, 27, and 37 wk of gestation and at 20 wk postpartum. Both groups exhibited augmented ventilatory responses to exercise throughout pregnancy. Significant aerobic conditioning effects observed in the exercised group between entry and third trimester of pregnancy testing included a 17% increase in oxygen pulse at peak exercise, reduction in the respiratory exchange ratio during standard submaximal exercise, and an increase in work rate at the onset of blood lactate accumulation. Onset of blood lactate accumulation did not change significantly in the control group. Respiratory exchange ratio at peak exercise was higher in postpartum tests compared with those conducted in late gestation in both groups. Peak postexercise lactate levels were also significantly lower in second and third trimesters of pregnancy testing compared with postpartum in the control group. This effect appeared to be prevented by physical conditioning in the exercised group. The study results support the hypothesis that moderate aerobic conditioning increases maximal aerobic power and the capacity for sustained submaximal exercise. Chronic exercise also appeared to help to preserve anaerobic working capacity in late gestation.

Adult↗

PubMed2000

Supine lower body negative pressure exercise during bed rest maintains upright exercise capacity.

Bed rest and spaceflight reduce exercise fitness. Supine lower body negative pressure (LBNP) treadmill exercise provides integrated cardiovascular and musculoskeletal stimulation similar to that imposed by upright exercise in Earth gravity. We hypothesized that 40 min of supine exercise per day in a LBNP chamber at 1.0-1.2 body wt (58 +/- 2 mmHg LBNP) maintains aerobic fitness and sprint speed during 15 days of 6 degrees head-down bed rest (simulated microgravity). Seven male subjects underwent two such bed-rest studies in random order: one as a control study (no exercise) and one with daily supine LBNP treadmill exercise. After controlled bed-rest, time to exhaustion during an upright treadmill exercise test decreased 10%, peak oxygen consumption during the test decreased 14%, and sprint speed decreased 16% (all P < 0.05). Supine LBNP exercise during bed rest maintained all the above variables at pre-bed-rest levels. Our findings support further evaluation of LBNP exercise as a countermeasure against long-term microgravity-induced deconditioning.

Adult↗

PubMed2004

Exercise training increases oxidative capacity and attenuates exercise-induced ultrastructural damage in skeletal muscle of aged horses.

Exercise training improves functional capacity in aged individuals. Whether such training reduces the severity of exercise-induced muscle damage is unknown. The purpose of the present study was to determine the effect of 10 wk of treadmill exercise training on skeletal muscle oxidative capacity and exercise-induced ultrastructural damage in six aged female Quarter horses (>23 yr of age). The magnitude of ultrastructural muscle damage induced by an incremental exercise test before and after training was determined by electron microscopic examination of samples of triceps, semimembranosus, and masseter (control) muscles. Maximal aerobic capacity increased 22% after 10 wk of exercise training. The percentage of type IIa myosin heavy chain increased in semimembranosus muscle, whereas the percentage of type IIx myosin heavy chain decreased in triceps muscle. After training, triceps muscle showed significant increases in activities of both citrate synthase and 3-hydroxyacyl-CoA-dehydrogenase. Attenuation of exercise-induced ultrastructural muscle damage occurred in the semimembranosus muscle at both the same absolute and the same relative workloads after the 10-wk conditioning period. We conclude that aged horses adapt readily to intense aerobic exercise training with improvements in endurance, whole body aerobic capacity, and muscle oxidative capacity, and heightened resistance to exercise-induced ultrastructural muscle cell damage. However, adaptations may be muscle-group specific.

Adaptation, Physiological↗

PubMed1987

Exercise intensity determines and climatic conditions modify the severity of exercise-induced asthma.

Recent studies have shown some evidence that exercise-induced asthma (EIA) may not be entirely explained by respiratory heat loss (RHL). We investigated the interrelationship between heat exchange, exercise intensity and EIA. In order to differentiate between the effects of RHL and exercise intensity, we arranged for tests to be performed with the same RHL, but with different intensities of exercise and inspired air conditions. Each of 8 asthmatic children exercised twice in random order for 6 min on a cycle ergometer. One test consisted of exercise performed at a greater level of effort while breathing room air, mean (+/- SE) air conditions being 25.0 +/- 0.4 degrees C and 15.7 +/- 0.2 mg H2O/L. The other test was performed at a lesser level of effort while breathing cold (0.0 +/- 0.5 degrees C) and dry air (O mg H2O/L). The mean ratio of minute ventilations in the 2 exercise tests was 1.78 +/- 0.03, but the RHL was similar in both tests. The EIA after the exercise at the greater level was more severe than after the lesser level, the percent fall in FEV2 from baseline being 36 +/- 7% and 21 +/- 5%, respectively (p less than 0.025). We conclude that the exercise level has a major role in determining the severity of EIA and that climatic conditions act as modifying factors.

Adolescent↗

PubMed2006

Exercise use as complementary therapy among breast and prostate cancer survivors receiving active treatment: examination of exercise intention.

BACKGROUND: Exercise is associated with an improved quality of life among cancer survivors. Previous research has highlighted the utility of the theory of planned behavior in understanding cancer survivors' intention to exercise. The purpose of this study was to extend the research on the theory of planned behavior in relation to exercise intention in breast cancer survivors and to provide preliminary evidence supporting its application with prostate cancer survivors during treatment. METHODS: Participants consisted of 126 breast and 82 prostate cancer survivors receiving active treatment. Participants completed self-administered, mail-in questionnaires that assessed demographic and medical variables, past exercise, and the theory of planned behavior. RESULTS: For breast cancer survivors, the results revealed that attitudes, subjective norm, and perceived behavioral control explained 66% of the variance in exercise intention with the instrumental component of attitude, subjective norm, and perceived behavioral control making significant unique contributions to intention. For prostate cancer survivors, attitudes, subjective norm, and perceived behavioral control explained 57% of the variance in exercise intention, with subjective norm and perceived behavioral control making significant unique contributions to intention. CONCLUSIONS: The results provide further support that the theory of planned behavior is a useful framework for understanding determinants of exercise intention in breast cancer survivors undergoing active treatment and preliminary support for prostate cancer survivors undergoing active treatment. When designing exercise interventions, differences in breast and prostate cancer survivors' exercise intention merit consideration.

Aged↗

PubMed2005

Prior arm exercise speeds the VO2 kinetics during arm exercise above the heart level.

PURPOSE: To test the hypothesis that the initial O2 uptake kinetics during exercise where the rise in blood flow (and, by implication, O2 delivery) to the working muscles during an abrupt increase in exercise intensity is reduced (i.e., arm exercise performed above the level of the heart) would be faster when preceded by a bout of high-intensity exercise. METHODS: Eleven physically active males completed two protocols, each consisting of two consecutive bouts of 6 min of high-intensity arm crank exercise separated by 6 min of recovery. In one protocol, the arm crank exercise was performed with the arms below the level of the heart ( HL). RESULTS: In the HL protocol, the amplitudes of the VO2 fast and slow component were unaffected by prior exercise, whereas the VO2 fast component time constant was significantly reduced in the second bout (49.8+/-22.1 vs 40.7+/-13.2 s; P<0.05). CONCLUSION: The results of this study demonstrate that prior high-intensity exercise caused a significant speeding of the VO2 fast component response during subsequent high-intensity arm crank exercise performed above, and not below, the level of the heart.

Adult↗

PubMed2002

Comparison of the peak exercise response measured by the ramp and 1-min step cycle exercise protocols in patients with exertional dyspnea.

STUDY OBJECTIVES: To compare the peak exercise response and determine the limits of agreement between the ramp and the 1-min step cycle protocols in a representative population of patients with exertional breathlessness attending a respiratory outpatient clinic. DESIGN: Crossover with the test order double blinded and randomized. SETTING: Outpatient exercise physiology laboratory. PATIENTS: Twenty-two patients (12 men; mean [SD] age, 59 [8] years; FEV(1), 71% [21%]) with lung disease and/or exertional breathlessness. INTERVENTION: Symptom-limited, maximum cycle exercise tests using a ramp and a 1-min step work rate (WR) protocols. The two protocols were assigned to subjects in a randomized manner. MEASUREMENTS AND RESULTS: Oxygen uptake (O(2)), minute ventilation (E), heart rate (HR), WR, exercise time, and Borg scores were compared at symptom-limited peak exercise. The mean (SD) peak values for the ramp and the step protocols, respectively, were as follows: peak O(2), 1.51 (0.44) L/min and 1.49 (0.43) L/min; peak E, 50.8 (12.9) L/min and 49.9 (14.5) L/min; and peak HR, 133 (24) beats/min and 131 (22) beats/min (p > 0.05). There were no significant differences between breathlessness and perceived exertion at peak exercise. Peak WR (WRpeak) and exercise time were significantly higher using the ramp protocol: 110.5 (37.1) W vs 105.6 (35.6) W, and 8.2 (2.0) min vs. 7.6 (1.9) min, respectively. CONCLUSIONS: The ramp protocol leads to a higher WRpeak, and this may have implications for exercise prescription. However, there were no significant differences between the two protocols for the peak physiologic responses. The choice of protocol for the measurement of maximal exercise capacity remains one of laboratory preference.

Aged↗

PubMed2005

Exercise training decreases ventilatory requirements and exercise-induced hyperinflation at submaximal intensities in patients with COPD.

STUDY OBJECTIVES: We hypothesized that endurance exercise training would reduce the degree of hyperinflation for a given level of exercise and thereby improve submaximal exercise endurance. METHODS: Twenty-four patients with COPD (mean FEV(1), 36.4 +/- 8.5% of predicted [+/- SD]) undertook a high-intensity cycle ergometer exercise training program for 45 min, three times a week for 7 weeks. Before and after training, the patients performed both an incremental exercise test to maximum and a constant work rate (CWR) test on a cycle ergometer at 75% of the peak work rate obtained in the pretraining incremental test. Ventilatory variables were measured breath-by-breath, and inspiratory capacity (IC) was measured every 2 min to assess changes in end-expiratory lung volume. RESULTS: After training, the increase in peak oxygen uptake was not statistically significant; however, the peak work rate increased by 12.9 +/- 10.3 W (p < 0.01). For the CWR test performed at the same work rate both before and after training, ventilation and breathing frequency (f) were lower after training (average, 1.97 L/min and 3.2 breaths/min, respectively; p < 0.01) and IC was greater (by an average of 133 mL, p < 0.05), signifying decreased hyperinflation. The increase in IC at the point of termination in the shortest CWR test for each individual (defined as isotime) correlated well with both the decreased f (r = 0.63, p = 0.001) and with the increase in CWR exercise endurance (average, 13.1 min, r = 0.46, p = 0.023). CONCLUSIONS: Exercise training in patients with severe COPD dramatically improves submaximal exercise endurance. Decreased dynamic hyperinflation may, in part, mediate the improvement in exercise endurance by delaying the attainment of a critically high inspiratory lung volume.

Aged↗

PubMed2000

Effectiveness of lateral slide exercise in an anterior cruciate ligament reconstruction rehabilitation home exercise program.

STUDY DESIGN: Two-group repeated measures design using a sample of convenience of subjects with anterior cruciate ligament (ACL) reconstructive surgery. OBJECTIVES: To determine the effect of incorporating one specific weight-bearing exercise (lateral slide exercise using a slide board) into an ACL reconstruction home exercise program. BACKGROUND: Reduced clinic visits have increased the importance of home exercise programs in knee ligament reconstruction rehabilitation. Few studies have been conducted to test the efficacy of specific exercises as part of a home-based treatment program on subjects who have undergone ACL reconstruction. METHODS AND MEASURES: Fourteen subjects who underwent patella tendon autograft reconstruction on one of their ACLs were studied. Testing consisted of the following 4 measurements: peak isometric knee extension torque, peak isometric knee flexion torque, maximum lateral step height, and lateral step-up repetitions to fatigue. Subjects were pretested at 8 weeks after surgery and were randomly placed into either a control or experimental group. The postsurgical rehabilitation was similar for both groups, except the experimental group incorporated lateral slide exercise into their home exercise program. All subjects were re-evaluated 14 weeks after surgery. RESULTS: A 2-way repeated measure ANOVA (group by test session), and posthoc testing revealed significant improvements in the slide group for quadricep strength (101.9 +/- 31.3 N m to 140.5 +/- 31.3 N m of torque), while the control group showed no significant increase (125.1 +/- 61.7 N m to 125.8 +/- 45.1 N m of torque). Lateral step height also improved in the slide group (from 22.9 +/- 5.3 cm to 28.7 +/- 5.6 cm), while the control group showed no increase (20.0 +/- 4.5 cm to 20.7 +/- 3.4 cm). Both groups increased in lateral step-up repetitions to fatigue. CONCLUSION: Including lateral slide exercise in a home exercise program after ACL reconstruction appears to improve knee extension strength.

Adult↗

PubMed2000

Moderate exercise increases the post exercise resting warm thermoregulatory response thresholds.

BACKGROUND: The purpose of this study was to evaluate the effect of exercise on the subsequent post-exercise core temperature thresholds for vasodilation and sweating. METHODS: On two separate days, with 6 subjects (3 males and 3 females), a whole-body water-perfused suit decreased mean skin temperature until the threshold for vasoconstriction was demonstrated. Mean skin temperature was then slowly increased (approximately 5.0 degrees C x h(-1)) until thresholds for vasodilation and sweating were clearly established. Subjects were cooled by decreasing water temperature until both esophageal and mean skin temperatures returned to near baseline values. Subjects then either performed 15 min of cycle ergometry (60% V(O2max)) followed by 30 min of recovery (Exercise), or remained seated with no exercise for 45 min (Control). Subjects were then cooled again until the onset of cutaneous vasoconstriction followed by a second warming period. The core temperature thresholds for vasodilation and sweating increased significantly by 0.49 degrees C and 0.19 degrees C post-exercise, respectively (p < 0.05). In order to compare thresholds between conditions in which both esophageal and mean skin temperatures were changing, we mathematically compensated for changes in skin temperatures using the established linear cutaneous contribution of skin to the control of vasodilation and sweating (10%). RESULTS: The calculated core temperature threshold (at a designated skin temperature of 36.0 degrees C) for vasodilation increased significantly from 36.56 +/- 0.12 degrees C to 37.11 +/- 0.21 degrees C post-exercise (p < 0.01). Likewise, the sweating threshold increased from 36.79 +/- 0.18 degrees C to 37.05 +/- 0.23 degrees C postexercise (p < 0.01). In contrast, sequential measurements, without exercise, demonstrate a time-dependent decrease (0.18 degrees C) in the sweating threshold, with no difference in the vasodilation threshold. CONCLUSION: These data indicate that exercise has a prolonged effect by increasing the post-exercise thresholds for both warm thermoregulatory responses.

Body Temperature Regulation↗

PubMed1992

Effects of anticipation, prior-exercise, and breathing frequency to ventilatory response during step exercise: a preliminary study.

We examined the effects of anticipation, prior-exercise, and restricted breathing frequency on the ventilatory transient response to bicycle step exercise (75 W, 4 min, 50 rpm), i.e., 1) whether the increase of work rate was anticipated by the subject or not, 2) whether the exercise was preceded by light exercise (25 W), or rest, and 3) whether the exercise entrained the breathing frequency (f: 12.5/min, or 25/min) or not (voluntary). The corresponding step-on exercise was randomly performed at least two to five times by one adult male subject. As a result, a) the initial rapid ventilatory component, phase 1, was not observed when initiated from light exercise, whereas the overshot phase 1 was observed from rest in anticipation and voluntary breathing frequency condition due to the rapid increase of tidal volume; b) compared with the anticipation condition, the phase 1 response of VE in the non-anticipation condition was slower with prior-rest, and not with prior-light exercise; and c) the restriction of the breathing frequency for entraining the exercise rhythm did not affect the initial rapid response, but decreased the fluctuation of VE in the steady state, compared to the condition of voluntary breathing frequency.

Adult↗

PubMed2004

Effect of physical exercise training on health-related quality of life and exercise tolerance in patients with left ventricular dysfunction.

OBJECTIVES: The improvement of exercise tolerance and quality of life (QOL) are essential in the treatment of patients with heart failure. The influence of physical exercise training on QOL was investigated in patients with left ventricular dysfunction. METHODS: Health-related QOL was evaluated using the Medical Outcomes Study Short-Form 36 Health Status Survey (SF-36) before and 3 months after individualized exercise training determined by cardiopulmonary exercise testing in 65 patients. The 44 patients who could carry out more than two-thirds of the prescribed exercise were classified into two groups: Group A (11 patients)with left ventricular ejection fraction < 40% and Group B (33 patients) with left ventricular ejection fraction > or = 40%. The remaining 21 patients served as the control group. RESULTS: The mean value of SF-36 improved significantly with exercise training only in Group A (50.8 +/- 25.3 to 62.1 +/- 22.2, p < 0.05). Group A also had an increase in peak Vo2 (18.9 +/- 3.5 to 21.4 +/- 3.6 ml/min/kg, p < 0.005) and a decrease in brain natriuretic peptide. The 24 patients (9 in Group A, 15 in Group B) with improved SF-36 values after the exercise training showed a negative correlation between the change of the mental component summary and the peak Vo2 (r = - 0.606, p < 0.05). CONCLUSIONS: Exercise training improves both the QOL, especially the mental component, and the exercise tolerance in patients with left ventricular dysfunction.

Adult↗

PubMed1982

Respiratory heat and water loss during exercise in patients with asthma. Effect of repeated exercise challenge.

A study was performed to investigate the loss of heat and water from the airways during repeated exercise challenge. Twenty-six asthmatic patients performed 6-8 min exercise on a bicycle ergometer at a workload equivalent to 57-85% of their predicted maximum working capacity. Sixteen patients performed two exercise tests separated by 40-52 min. Exercise-induced asthma (EIA) occurred in all patients after initial challenge but eight had significant protection from EIA following a second challenge. This protection was not associated with a reduction in heat and water loss from the airways during exercise. A further 10 patients performed two exercise tests 2-3 h apart. The second test was preceded by the administration of 200 microgram salbutamol aerosol. There was no significant difference between the two tests in loss of heat and water from the airways during exercise. Exercise-induced asthma occurred in all patients after the initial challenge but was inhibited by the salbutamol after the second challenge. Thus the reduction in EIA as a result of a refractory period or in response to aerosol salbutamol is not due to changes in heat and water loss from the airways during exercise.

Adolescent↗

PubMed1997

A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis. The Fitness Arthritis and Seniors Trial (FAST).

OBJECTIVE: To determine the effects of structured exercise programs on self-reported disability in older adults with knee osteoarthritis. SETTING AND DESIGN: A randomized, single-blind clinical trial lasting 18 months conducted at 2 academic medical centers. PARTICIPANTS: A total of 439 community-dwelling adults, aged 60 years or older, with radiographically evident knee osteoarthritis, pain, and self-reported physical disability. INTERVENTIONS: An aerobic exercise program, a resistance exercise program, and a health education program. MAIN OUTCOME MEASURES: The primary outcome was self-reported disability score (range, 1-5). The secondary outcomes were knee pain score (range, 1-6), performance measures of physical function, x-ray score, aerobic capacity, and knee muscle strength. RESULTS: A total of 365 (83%) participants completed the trial. Overall compliance with the exercise prescription was 68% in the aerobic training group and 70% in the resistance training group. Postrandomization, participants in the aerobic exercise group had a 10% lower adjusted mean (+/- SE) score on the physical disability questionnaire (1.71 +/- 0.03 vs 1.90 +/- 0.04 units; P<.001), a 12% lower score on the knee pain questionnaire (2.1 +/- 0.05 vs 2.4 +/- 0.05 units; P=.001), and performed better (mean [+/- SE]) on the 6-minute walk test (1507 +/- 16 vs 1349 +/- 16 ft; P<.001), mean (+/-SE) time to climb and descend stairs (12.7 +/- 0.4 vs 13.9 +/- 0.4 seconds; P=.05), time to lift and carry 10 pounds (9.1 +/- 0.2 vs 10.0 +/- 0.1 seconds; P<.001), and mean (+/-SE) time to get in and out of a car (8.7 +/- 0.3 vs 10.6 +/- 0.3 seconds; P<.001) than the health education group. The resistance exercise group had an 8% lower score on the physical disability questionnaire (1.74 +/- 0.04 vs 1.90 +/- 0.03 units; P=.003), 8% lower pain score (2.2 +/- 0.06 vs 2.4 +/- 0.05 units; P=.02), greater distance on the 6-minute walk (1406 +/- 17 vs 1349 +/- 16 ft; P=.02), faster times on the lifting and carrying task (9.3 +/- 0.1 vs 10.0 +/- 0.16 seconds; P=.001), and the car task (9.0 +/- 0.3 vs 10.6 +/- 0.3 seconds; P=.003) than the health education group. There were no differences in x-ray scores between either exercise group and the health education group. CONCLUSIONS: Older disabled persons with osteoarthritis of the knee had modest improvements in measures of disability, physical performance, and pain from participating in either an aerobic or a resistance exercise program. These data suggest that exercise should be prescribed as part of the treatment for knee osteoarthritis.

Activities of Daily Living↗