Effect of acute submaximal exercise on intraocular pressure in athletes and sedentary subjects

The existing literature is controversial regarding the relationship between physical fitness and intraocular pressure (IOP). Therefore, the effects of acute submaximal exercise on IOP were compared in athletes and sedentary subjects. Acute exercise increased IOP in male athletes, but had no effect in sedentary men. Also, it decreased IOP in sedentary women, but had no effect in female athletes. Sex and physical fitness both were significant factors influencing the changes in IOP due to exercise. These results suggest that acute dynamic exercise is useful to decrease IOP in sedentary women, but not in male athletes. These results may help glaucoma screeners.     

Strength and physiological response to exercise in patients with chronic fatigue syndrome

OBJECTIVE: To measure strength, aerobic exercise capacity and efficiency, and functional incapacity in patients with chronic fatigue syndrome (CFS) who do not have a current psychiatric disorder. METHODS: Sixty six patients with CFS without a current psychiatric disorder, 30 healthy but sedentary controls, and 15 patients with a current major depressive disorder were recruited into the study. Exercise capacity and efficiency were assessed by monitoring peak and submaximal oxygen uptake, heart rate, blood lactate, duration of exercise, and perceived exertion during a treadmill walking test. Strength was measured using twitch interpolated voluntary isometric quadriceps contractions. Symptomatic measures included physical and mental fatigue, mood, sleep, somatic amplification, and functional incapacity. RESULTS: Compared with sedentary controls, patients with CFS were physically weaker, had a significantly reduced exercise capacity, and perceived greater effort during exercise, but were equally unfit. Compared with depressed controls, patients with CFS had significantly higher submaximal oxygen uptakes during exercise, were weaker, and perceived greater physical fatigue and incapacity. Multiple regression models suggested that exercise incapacity in CFS was related to quadriceps muscle weakness, increased cardiovascular response to exercise, and body mass index. The best model of the increased exercise capacity found after graded exercise therapy consisted of a reduction in submaximal heart rate response to exercise. CONCLUSIONS: Patients with CFS were weaker than sedentary and depressed controls and as unfit as sedentary controls. Low exercise capacity in patients with CFS was related to quadriceps muscle weakness, low physical fitness, and a high body mass ratio. Improved physical fitness after treatment was associated with increased exercise capacity. These data imply that physical deconditioning helps to maintain physical disability in CFS and that a treatment designed to reverse deconditioning helps to improve physical function.     

EFFECTS OF EXERCISE ON SOMATOSENSORY-EVOKED POTENTIALS

The aim of this study was to investigate the effect of acute and regular exercise on somatosensory-evoked potentials (SEP). The study group was designed as 9 female and 7 male volleyball players, and the control group as 9 female and 7 male sedentary students. The P1 and P2 latency and amplitude values were measured by tibial nerve stimulation on both lower extremities in the study groups before and after exercise on a treadmill. Intra-group comparison was made to evaluate the acute effects of exercise, and inter-group comparison for the chronic effects of it. Statistically significant difference was determined in pre-exercise right P2 amplitudes and post-exercise left P2 latencies of female volleyball players and sedentary girls. There was significant difference between only the pre-exercise left P2 latency when comparison was made between the sportsmen and sedentary male subject groups. There were significant differences between the pre-exercise left P1 and P2 latency values of sportswomen and right P2 amplitudes of sedentary female subjects. There was no significant difference between left P2 latency values of sportsmen and sedentary male subjects. In conclusion, it was determined that acute and regular exercise shortened the latency of sensory-evoked potentials while decreasing their amplitudes. When evaluating the sensory-evoked potentials in electrophysiology laboratories, the exercise capacity and physical activity levels of the subjects should be considered.     

Effects of exercise on somatosensory-evoked potentials

The aim of this study was to investigate the effect of acute and regular exercise on somatosensory-evoked potentials (SEP). The study group was designed as 9 female and 7 male volleyball players, and the control group as 9 female and 7 male sedentary students. The P1 and P2 latency and amplitude values were measured by tibial nerve stimulation on both lower extremities in the study groups before and after exercise on a treadmill. Intra-group comparison was made to evaluate the acute effects of exercise, and inter-group comparison for the chronic effects of it. Statistically significant difference was determined in pre-exercise right P2 amplitudes and post-exercise left P2 latencies of female volleyball players and sedentary girls. There was significant difference between only the pre-exercise left P2 latency when comparison was made between the sportsmen and sedentary male subject groups. There were significant differences between the pre-exercise left P1 and P2 latency values of sportswomen and right P2 amplitudes of sedentary female subjects. There was no significant difference between left P2 latency values of sportsmen and sedentary male subjects. In conclusion, it was determined that acute and regular exercise shortened the latency of sensory-evoked potentials while decreasing their amplitudes. When evaluating the sensory-evoked potentials in electrophysiology laboratories, the exercise capacity and physical activity levels of the subjects should be considered.     

LONG-TERM EFFECTS OF MILD EXERCISE ON INTRAOCULAR PRESSURE IN ATHLETES AND SEDENTARY SUBJECTS

The long-term effects of acute submaximal exercise on intraocular pressures (IOPs) of right-and left-eyes and recovery times to basement levels of IOP in postexercise periods in sedentary and physically fit subjects were investigated. Twenty-five sedentary and 24 physically fit subjects, ranging in age 17 to 22 years, participated. Intraocular pressures were measured by a pneumotonometer. Measurements were taken in the morning at about nine (at rest) and immediately, 30 min and 2 h after acute submaximal exercise. In sedentary subjects, IOPs of both right- and left-eyes decreased immediate after exercise, but, these decreases in both eyes continued 30 min and 2 h after exercise. In physically fit subjects, IOPs of both right- and left-eyes increased immediate after exercise, but decreased after 30 min exercise compared to basement levels, and this decrease continued 2 h after exercise. Acute submaximal exercise decreased IOPs of right and left eyes over a period 2 h in sedentary and physically fit subjects. IOP reducing after exercise was different between right- and left-eyes in sedentary subjects. These results suggest that exercise can be used in ocular hypertension treatment.     

Long-term effects of mild exercise on intraocular pressure in athletes and sedentary subjects

The long-term effects of acute submaximal exercise on intraocular pressures (IOPs) of right-and left-eyes and recovery times to basement levels of IOP in postexercise periods in sedentary and physically fit subjects were investigated. Twenty-five sedentary and 24 physically fit subjects, ranging in age 17 to 22 years, participated. Intraocular pressures were measured by a pneumotonometer. Measurements were taken in the morning at about nine (at rest) and immediately, 30 min and 2 h after acute submaximal exercise. In sedentary subjects, IOPs of both right- and left-eyes decreased immediate after exercise, but, these decreases in both eyes continued 30 min and 2 h after exercise. In physically fit subjects, IOPs of both right- and left-eyes increased immediate after exercise, but decreased after 30 min exercise compared to basement levels, and this decrease continued 2 h after exercise. Acute submaximal exercise decreased IOPs of right and left eyes over a period 2 h in sedentary and physically fit subjects. IOP reducing after exercise was different between right- and left-eyes in sedentary subjects. These results suggest that exercise can be used in ocular hypertension treatment.     

EFFECTS OF EXERCISE ON VISUAL EVOKED POTENTIALS

The aim of this study was to investigate the effects of acute or habitual exercise on visual evoked potentials (VEP). The study group consisted of 9 female and 7 male volleyball players and the control group contained 9 female and 7 male students who were not involved in any sportive activity. The N75, P100, and N145 latency and amplitudes were measured before and after exercise. Intragroup comparison was made to evaluate the acute effects and intergroup comparison for the chronic effects of exercise. Significant differences were noted between athletes and the sedentary subjects in terms of pre-exercise left-N145 latencies and amplitudes and left -P100 amplitudes. Right-eye N145 latencies of inactive female subjects obtained before and after exercise were also statistically different. The results suggest that acute and habitual exercise affects the VEP responses independent from the body temperature and other physiological parameters. Small sized pre-exercise P100 amplitudes in the athletes can be attributed to the effect of rapid visual-activity-demanding sports on the central nervous system. Visual evoked potentials maybe used as neurophysiological criteria in defining the performance of an athlete.     

Effects of exercise on visual evoked potentials

The aim of this study was to investigate the effects of acute or habitual exercise on visual evoked potentials (VEP). The study group consisted of 9 female and 7 male volleyball players and the control group contained 9 female and 7 male students who were not involved in any sportive activity. The N75, P100, and N145 latency and amplitudes were measured before and after exercise. Intragroup comparison was made to evaluate the acute effects and intergroup comparison for the chronic effects of exercise. Significant differences were noted between athletes and the sedentary subjects in terms of pre-exercise left-N145 latencies and amplitudes and left -P100 amplitudes. Right-eye N145 latencies of inactive female subjects obtained before and after exercise were also statistically different. The results suggest that acute and habitual exercise affects the VEP responses independent from the body temperature and other physiological parameters. Small sized pre-exercise P100 amplitudes in the athletes can be attributed to the effect of rapid visual-activity-demanding sports on the central nervous system. Visual evoked potentials maybe used as neurophysiological criteria in defining the performance of an athlete.     

Comparison of the effects of acute and regular exercise on intraocular pressure in Turkish athlete and sedentarians

The aim of this study was to investigate the changes that take place in IOP in athletes and people leading sedentary lives subjected to aerobic and anaerobic exercise and how chronic exercise could affect these changes. The study included 20 sportsmen (Group 1), and 20 people leading sedentary lives (Group 2). The intensity of the exercise for both groups was determined according to the Karvonen protocol and executed as an aerobic exercise program involving running on a treadmill for 30 min. Subjects in both groups were subjected to anaerobic exercise according to the Wingate test protocol for 30 s. The intraocular pressure of all subjects before exercise and after aerobic and anaerobic exercise were measured. The IOP before and after exercise aerobic and anaerobic were evaluated by the Willcoxon test whereas the right and left IOP before exercise and after the aerobic and anaerobic exercise programs in both groups were evaluated using the Mann Whitney U test. p values of <.05 were considered significant. Significant differences were found when the pre-exercise and post-aerobic and anaerobic exercise IOPs of the groups were compared (p < .05). Comparison of the post-anaerobic and aerobic exercise revealed a fall in the IOPs of the subjects after the aerobic exercise (p < .01). In this study, exercise was found to lead to a fall in the IOP in both sportsmen and those leading sedentary lives with the fall less apparent under anaerobic conditions than under aerobic conditions. In conclusion, therefore, it can be said that in those with an increased intraocular pressure, regular, moderately intense aerobic exercise rather than short-lived intense exercise could be more useful.     

COMPARISON OF THE EFFECTS OF ACUTE AND REGULAR EXERCISE ON INTRAOCULAR PRESSURE IN TURKISH ATHLETE AND SEDENTARIANS

The aim of this study was to investigate the changes that take place in IOP in athletes and people leading sedentary lives subjected to aerobic and anaerobic exercise and how chronic exercise could affect these changes. The study included 20 sportsmen (Group 1), and 20 people leading sedentary lives (Group 2). The intensity of the exercise for both groups was determined according to the Karvonen protocol and executed as an aerobic exercise program involving running on a treadmill for 30 min. Subjects in both groups were subjected to anaerobic exercise according to the Wingate test protocol for 30 s. The intraocular pressure of all subjects before exercise and after aerobic and anaerobic exercise were measured. The IOP before and after exercise aerobic and anaerobic were evaluated by the Willcoxon test whereas the right and left IOP before exercise and after the aerobic and anaerobic exercise programs in both groups were evaluated using the Mann Whitney U test. p values of <.05 were considered significant. Significant differences were found when the pre-exercise and post-aerobic and anaerobic exercise IOPs of the groups were compared (p < .05). Comparison of the post-anaerobic and aerobic exercise revealed a fall in the IOPs of the subjects after the aerobic exercise (p < .01). In this study, exercise was found to lead to a fall in the IOP in both sportsmen and those leading sedentary lives with the fall less apparent under anaerobic conditions than under aerobic conditions. In conclusion, therefore, it can be said that in those with an increased intraocular pressure, regular, moderately intense aerobic exercise rather than short-lived intense exercise could be more useful.     

The relationship between body composition and sleep architecture in athletes

Sleep is essential for athletes to recover physical fitness. It has been suggested that sleep is affected by muscle volume. Compared to female athletes, male athletes with greater muscle volume may have inferior objective sleep quality. This study aimed to assess the relationship between body composition and objective sleep parameters in male and female athletes. The body composition of 17 male and 19 female collegiate athletes were measured, and they underwent overnight home sleep monitoring. Compared with female athletes, male athletes had more muscle mass and less fat mass. Moreover, male athletes had lower sleep efficiency, longer sleep onset latency, higher arousal index, less rapid eye movement (REM) sleep, and lower percentage of slow-wave (N3) sleep in the initial non-REM sleep. Furthermore, the percentage of muscle mass was inversely related, whereas fat mass or percentage of fat mass was directly related to the percentage of N3 sleep in the initial non-REM sleep. Overall, there were no significant association between sex and sleep parameters. However, a significant correlation was found within both subgroups. Objective sleep quality was suggested to be worse in male athletes than in female athletes, implying that sleep architecture may be related to the muscle volume.     

Intra-ocular pressure changes during maximal isometric contraction: does this reflect intra-cranial pressure or retinal venous pressure?

Recent publications have suggested that intra-ocular pressure (IOP) may be an indirect assessment of intra-cranial pressure (ICP). Both IOP and ICP have similar physiologic pressure ranges and similar responses to changes in intra-abdominal, intra-thoracic and aortic pressure. Previous studies have demonstrated the relationships between retinal arterial pressure and aortic pressure, intra-ocular pressure and retinal venous pressure, intra-cranial pressure and retinal venous pressure. Power athletes routinely utilize the Valsalva maneuver during weightlifting. In fact there are reports of stroke, cerebral hemorrhage, subarachnoid hemorrhage, conjunctival, foveal and retinal hemorrhage, retinal detachment, hiatal hernia and pneumothorax associated with weightlifting. These events are thought to occur secondary to the extreme pressure elevations that occur in the intra-abdominal, intra-thoracic, intra-cranial, intra-ocular and vascular compartments. To date no human studies have examined the IOP changes that may occur with heavy resistance exercise. Therefore, we recruited power athletes (n = 11), who had participated in prior studies, from the local metropolitan area. The athletes had blood pressure status, drug screening and medical histories performed during previous investigations. Intra-ocular pressure was measured by noncontact tonometry at rest and during maximal isometric contraction. All subjects resting IOP were within normal ranges (mean 13 +/- 2.8 mmHg). Intra-ocular pressures were significantly (p < 0.0001) elevated in each subject during maximal contraction (mean 28 +/- 9.3 mmHg). One subject's IOP reached 46 mmHg during maximal contraction. Linear regression analysis demonstrated a significant linear relationship (r = 0.62, p < 0.0001) in the net change of IOP from rest to maximal contraction for each subject. This study demonstrates that IOP elevates to pathophysiologic levels during resistance exercise. The findings of conjunctival hemorrhages in two subjects further supports IOP being reflective of retinal venous pressure. The enormous pressures generated by power athletes during weightlifting leads to elevations in ICP which obstruct venous outflow leading to hemorrhage and elevations in IOP. The question remains as to whether these intermittent bursts of elevated IOP can lead to long-term pathological sequelae.     

Transplantation immunology and the central nervous system

Abstract

Recent publications have suggested that intra-ocular pressure (IOP) may be an indirect assessment of intracranial pressure (ICP). Both IOP and ICP have similar physiologic pressure ranges and similar responses to changes in intra-abdominal, intra-thoracic and aortic pressure. Previous studies have demonstrated the relationships between retinal arterial pressure and aortic pressure, intra-ocular pressure and retinal venous pressure, intra-cranial pressure and retinal venous pressure. Power athletes routinely utilize the Valsalva maneuver during weightlifting. In fact there are reports of stroke, cerebral hemorrhage, subarachnoid hemorrhage, conjunctivalfoveal and retinal hemorrhage, retinal detachment, hiatal hernia and pneumothorax associated with weightlifting. These events are thought to occur secondary to the extreme pressure elevations that occur in the intra-abdominal, intra-thoracic, intra-cranial, intra-ocular and vascular compartments. To date no human studies have examined the IOP changes that may occur with heavy resistance exercise. Therefore, we recruited power athletes (n = 11), who had participated in prior studies, from the local metropolitan area. The athletes had blood pressure status, drug screening and medical histories performed during previous investigations. Intra-ocular pressure was measured by noncontact tonometry at rest and during maximal isometric contraction. All subjects resting IOP were within normal ranges (mean 13 ± 2.8 mmHg). Intra-ocular pressures were significantly (p < 0.0001) elevated in each subject during maximal contraction (mean 28 ± 9.3 mmHg). One subject’s IOP reached 46 mmHg during maximal contraction. Linear regression analysis demonstrated a significant linear relationship (x =0.62, p < 0.0001) in the net change of IOP from rest to maximal contraction for each subject. This study demonstrates that IOP elevates to pathophysiologic levels during resistance exercise. The findings of conjunctival hemorrhages in two subjects further supports IOP being reflective of retinal venous pressure. The enormous pressures generated by power athletes during weightlifting leads to elevations in ICP which ‘obstruct venous outflow leading to hemorrhage and elevations in IOP. The question remains as to whether these intermittent bursts of elevated IOP can lead to long-term pathological sequelae. [Neurol Res 1999; 21: 243-246]     

Improvements in physical fitness in adults with Down syndrome

The effectiveness of an exercise training program for 52 adults with Down syndrome (M age = 39.4 years) was evaluated. The training program consisted of cardiovascular (30 minutes) and strength exercise (15 minutes) for 12 weeks, 3 days a week for 45-minutes per session. Compared to control subjects, the training group improved significantly in cardiovascular fitness and muscular strength and endurance and had a slight but significant reduction in body weight. Greater effort must be made to promote increases in physical activity participation among persons with Down syndrome and developmental disabilities in order to reduce the potential health risks associated with low fitness and sedentary behavior.     

An inactive lifestyle and low physical fitness are associated with functional somatic symptoms in adolescents. The TRAILS study

Objective

An inactive lifestyle has been associated with functional somatic symptoms (FSS), but findings are contradictory. Moreover, mediating factors in this relationship are unclear. We examined whether low physical activity was related to FSS in adolescents, and whether this association was mediated by low physical fitness.

Methods

This study was part of the Dutch longitudinal cohort study TRAILS, in which 1816 adolescents (mean age 16.3 years, SD 0.7) participated during the third (T3) and 1881 (mean age 19.1 years, SD 0.6) during the fourth (T4) assessment waves. Adolescents' exercise and sedentary behavior levels and the number of FSS were assessed by questionnaires at T3 and T4. Physical fitness (VO₂Max) was determined for 687 adolescents by a shuttle run test at T3. The association between physical activity and FSS was examined with bootstrapped linear regression analyses, adjusted for smoking and gender. In addition, bootstrapped mediation analyses were performed.

Results

A lack of exercise (b = 0.05, bootstrap 95%-CI: 0.01 to 0.09) and high sedentary behavior (b = 0.10, bootstrap 95%-CI: 0.06 to 0.14) at T3 were positively associated with FSS at T3. Since no longitudinal effects were found, shared associations were tested instead of mediation. The associations between a lack of exercise and FSS, and sedentary behavior and FSS were shared with physical fitness (b = 0.01, bootstrap 95%-CI: 0.010.02. and b = 0.03, bootstrap 95%-CI: 0.010.05).

Conclusion

An inactive lifestyle is associated with increased FSS in adolescents. Only part of this association is shared with low physical fitness.     

Sexual differences in onset of disease and response to exercise in a transgenic model of ALS

Transgenic mice that overexpress the mutant human SOD1 gene (hSOD1) serve as an animal model for amyotrophic lateral sclerosis (ALS). Age and sex are recognized as risk factors for ALS, but physical activity remains controversial. Therefore, we investigated the effect of exercise on the phenotype of male and female hSOD1 mice. Onset of disease, progression of disease and survival were measured in low-copy and high-copy hSOD1 mice that were randomized to an exercise or sedentary group. We found that onset of disease was different for the two sexes: significantly earlier in male than in female hSOD1 mice. Exercise delayed the onset of disease in female but not in male hSOD1 mice. Also, exercise delayed the total survival time in female high-copy hSOD1 mice. Muscle morphometry and motor neuron counts were similar in all experimental groups at the end of training. Sedentary female hSOD1 mice showed more frequently irregular estrous cycles suggesting a higher estrogen exposure in exercising female mice. These results suggest a possible neuroprotective effect of female sex hormones and support the view that ALS patients should not avoid regular exercise.     

Maximal exercise response of paraplegic wheelchair road racers.

The maximal metabolic responses of 11 paraplegic wheelchair road racers were evaluated with 2 wheelchair exercise protocols: increasing speed and increasing resistance. The maximal heart rates, minute ventilations and oxygen uptakes were similar for the 2 tests, indicating that either protocol is suitable for maximal wheelchair dynamometer exercise tests for groups. The resulting data were then compared to published data on maximal arm exercise by athletic and non athletic paraplegics and ambulatory males of the same age group. The combined mean values for both exercise tests of maximal oxygen consumption rate (VO2max = 37.4 ml/kg/min), minute ventilation (VE = 109.4 l/min), respiratory exchange quotient (RQmax = 1.18) and heart rate (187 beats/min) are in the mid range of reported data on wheelchair athletes. The mean RQ and heart rate values were similar to those achieved by ambulatory individuals performing maximal exercise tests. The mean VO2max of 37.4 ml/kg/min in our subjects is comparable to that achieved by sedentary ambulatory males of this age group. The data and the comparison to published data suggest several conclusions: in some parameters elite male paraplegic road racers have maximal values similar to those of ambulatory males, and in others they have maximal values substantially lower than might be expected; there is considerable variability among paraplegics in the metabolic responses to maximal exercise, most likely related to differences in cardiovascular fitness; and paraplegics can improve their cardiovascular fitness by training.     

The effect of exercise on normal mood

Research has shown that aerobic exercise is effective in alleviating depression. However, the contention that aerobic exercise similarly has an enduring beneficial psychological effect on the mood of normal, non-depressed individuals has not been verified. Research examining the effects of exercise on normal mood has yielded inconsistent findings, due in part to methodological shortcomings. The present study attempted to rectify these methodological difficulties and evaluated the effect of 13 weeks of aerobic exercise on the mood of normal, non-depressed men and women. Groups intended to be non-aerobic and waiting list controls were included in the design, as were a stratified random sampling procedure, measurement of physical fitness, and a seven-day pre/post-program assessment period for both positive and negative mood. Results indicated that, although subjects demonstrated significant improvement in physical fitness, there were no significant changes in either positive or negative mood. Thus, in contrast to effects with clinical depressives, exercise does not appear to have any long-term beneficial effect on the mood of non-depressed individuals selected from a normal, i.e. non-clinical, population.     

Beta-endorphin and components of depression as powerful discriminators between joggers and sedentary middle-aged men

This study identifies the relative importance of resting plasma beta-endorphin, used as a marker of perceived stress, and components of non-clinical depression that discriminate between physically active joggers and sedentary men. The profiles of joggers (n = 10) and sedentary (n = 10) middle-aged men (40-60 yr) were compared. The jogger group had been running about 20 miles per week for at least 3 yr. Results: as expected, the joggers exhibited greater physical fitness, but lower circulating beta-endorphin (measured with the subjects at rest). The joggers also exhibited greater emotional stability (Eysenck scores), and lower depression (MMPI Scale 2 scores). In addition, the joggers had lower scores on MMPI subscales of depression: subjective depression, physical malfunctioning, mental dullness, and brooding. Multivariate discriminant function analyses showed that subjective depression, beta-endorphin, and physical malfunctioning were powerful discriminators between the jogger and sedentary groups. In conclusion: (1) subjective depression appeared to be the MMPI component of depression that most powerfully discriminated between joggers and sedentary middle-aged men in this study. (2) Lower beta-endorphin may be an adaptation to exercise training and was related to greater emotional stability and lower depression, especially lower subjective depression. (3) The lower beta-endorphin in the jogger group may be related to lower perceived stress in the joggers, relative to the sedentary group.     

Enhanced parasympathetic activity of sportive women is paradoxically associated to enhanced resting energy expenditure

The resting energy expenditure and the adaptation of the autonomic nervous system induced by sport activities in sedentary women and in female professional basketball players have been studied. Resting energy expenditure, body composition and the level of activity of the autonomic nervous system were measured before and after a period of six months. The physical activity induced an increase in resting energy expenditure and free fat mass without variations in body weight. Basketball players showed a significant increase in the parasympathetic activity, measured by the power spectral analysis of the heart rate variability. These findings demonstrate that resting energy expenditure is higher in the athletes than in sedentary women, despite the augmented parasympathetic activity that is usually related to lower energy expenditure.