The ties that bind: perceived social support, stress, and IBS in severely affected patients.

BACKGROUND: This study assessed the association between social support and the severity of irritable bowel syndrome (IBS) symptoms in a sample of severely affected IBS patients recruited to an NIH-funded clinical trial. In addition, we examined if the effects of social support on IBS pain are mediated through the effects on stress. METHODS: Subjects were 105 Rome II diagnosed IBS patients (F = 85%) who completed seven questionnaires which were collected as part of a pretreatment baseline assessment. KEY RESULTS: Partial correlations were conducted to clarify the relationships between social support and clinically relevant variables with baseline levels of psychopathology, holding constant number of comorbid medical diseases, age, gender, marital status, ethnicity, and education. Analyses indicated that social support was inversely related to IBS symptom severity. Social support was positively related with less severe pain. A similar pattern of data was found for perceived stress but not quality of life impairment. Regression analyses examined if the effects of social support on pain are mediated by stress. The effects of social support on bodily pain were mediated by stress such that the greater the social support the less stress and the less pain. This effect did not hold for symptom severity, quality of life, or psychological distress. CONCLUSIONS & INFERENCES: This study links the perceived adequacy of social support to the global severity of symptoms of IBS and its cardinal symptom (pain). It also suggests that the mechanism by which social support alleviates pain is through a reduction in stress levels.

Quadriceps concentric and eccentric exercise 2: differences in muscle strength, fatigue and EMG activity in eccentrically-exercised sore and non-sore muscles.

The purpose of this study was to determine whether the previously reported muscle weakness and increases in EMG and EMG/force ratio after eccentric exercise were related to ensuing soreness or simply to the exercise mode. Delayed-onset muscle soreness, maximal voluntary force and the surface electromyogram (EMG) of the quadriceps were studied in 10 healthy male subjects following 20 min of bench-stepping with a constant leading leg. Prior to stepping and at 0, 0.25, 0.50, 0.75, 1, 3, 24 and 48 h afterwards the subjects performed a 30 s isometric maximal voluntary contraction (MVC) of the extensors of each leg during which the isometric force and the root mean square voltage of the surface EMG (rms EMG) were recorded. Muscle soreness was recorded prior to and at 0, 0.75, 3, 24 and 48 h after the stepping task by means of a force probe. No soreness was experienced in the concentrically exercised muscles, but in the eccentrically exercised muscles 5 subjects were not sore and 5 experienced soreness after 24 h, increasing to 48 h. There were no significant differences between sore and non-sore muscles in muscle weakness, fatigue during 30 s, the EMG amplitudes or the EMG/force ratios during peak force and the 30 s MVC (p >0.05). Muscle weakness following eccentric exercise was related to the exercise mode and was independent of subsequent soreness. Both weakness and soreness may be related to muscle damage, but involve different mechanisms.

Quadriceps concentric and eccentric exercise 1: changes in contractile and electrical activity following eccentric and concentric exercise.

The purpose of this study was to determine whether or not losses of strength or endurance following eccentric and concentric exercise are associated with reduced excitation. The effects of eccentric and concentric work on maximal voluntary isometric contraction (MVC) and surface electromyogram (EMG) of the quadriceps were studied in 10 healthy male subjects following bench-stepping for 20 min with a constant leading leg. Prior to stepping and at 0, 0.25, 0.50, 0.75, 1, 3, 24 and 48 h afterwards the subjects performed a 30 s leg extension MVC with each leg during which the isometric force and the root mean square voltage of the EMG were recorded. In the eccentrically exercised muscles (ECC), MVC0-3 (force during the first 3 s of contraction) fell immediately after the bench-stepping exercise to 88+/-2% (mean+/-SE) of the pre-exercise value and remained significantly lower than the concentrically exercised muscles (p<0.05). The muscle weakness in the ECC could not be attributed to central fatigue as surface EMG amplitude at MVC0-3 increased during the recovery period. Muscle weakness after eccentric exercise appears to be due to contractile failure, which is not associated with a reduction in excitation as assessed by surface EMG. Muscular fatigue over 30 s did not change in the two muscle groups after exercise (p = 0.79), indicating that the ECC were weaker but not more fatiguable after exercise.

Alcohol and the continuation of early marital aggression.

BACKGROUND: Husband alcohol use has frequently been found to be related to husband-to-wife marital violence. Research has demonstrated a prospective link between husband alcohol use before marriage and husband-to-wife aggression in the first year of marriage. The present study examined the relationships of husband violence, marital conflict, and couple's alcohol use in the first year of marriage to husband-to-wife marital violence in the second and third years of marriage. METHODS: Newlywed couples were recruited at the time of marriage and were interviewed regarding alcohol use and experience with violence before marriage, 1 year after marriage, and 3 years after marriage. RESULTS: Year 1 violence was predictive of subsequent marital violence. Husband and wife drinking patterns in the first year of marriage interacted to predict violence in later years. The most violence in subsequent years occurred in couples where the husband was a heavy drinker and the wife was not. Husbands who were violent in year 1 were more likely to be violent in later years. When no violence occurred in the first year, frequent use of verbal aggression in year 1 was predictive of violence in subsequent years. CONCLUSIONS: The predictive value of husband drinking patterns for subsequent violence extends beyond the transition to marriage. The fact that husband and wife alcohol use interacted to predict future aggression suggests that the relationship between husband alcohol use and marital violence is not spurious nor the result of conflict and violence promoting alcohol use. The findings may reflect multiple instances of acute intoxication and/or alcohol-related stress and conflict within the relationship, both of which may increase the likelihood of aggression.

Drinking and marital aggression in newlyweds: an event-based analysis of drinking and the occurrence of husband marital aggression.

OBJECTIVE: Research suggests that domestically violent men are more likely to be heavy drinkers than nonviolent men. However, very little data has addressed the relationship between the occurrence of a domestic violence episode and the co-occurrence of husband or wife alcohol consumption. The purpose of this study was to examine the relationship between husband and wife drinking and whether the most serious conflict involved verbal aggression, moderate physical aggression or severe physical aggression. METHOD: Newlywed couples (n = 366) who were assessed with respect to risk factors for marital violence at the time of marriage were interviewed at the end of their first year of marriage. These in-person interviews focused on characteristics (location, presence of other people, husband drinking, wife drinking) of the most severe verbal conflict, and the first and the most severe episode of physical aggression. RESULTS: After controlling for individual difference risk factors including husband and wife drinking patterns, husband drinking was more likely in episodes of physical vs episodes of verbal aggression. This finding was consistent in both husband and wife, and consistent in both between-groups and within-groups analyses. Wife drinking was largely unrelated to occurrence or severity of violence. CONCLUSIONS: These results support the contention that alcohol use may contribute to the occurrence and/or severity of domestic violence, particularly in the early stages of marriage.

The modeling of alcohol consumption: a meta-analytic review.

OBJECTIVE: Modeling, or the imitation of another's behavior, has been proposed to influence alcohol consumption. The literature dealing with effects of modeling on alcohol consumption was reviewed using meta-analytic procedures in order to determine the strength of the modeling effect and the variables that moderate the effect. METHOD: Thirteen studies were examined in which participant's alcohol consumption in the presence of a high consumption model was compared to a low consumption model condition or a no-model condition. Analyses were conducted for the four dependent measures utilized in the literature: amount consumed, blood alcohol concentration, number of sips taken and volume per sip. Mean effect sizes (d) were calculated for each dependent measure and moderator variables were examined. RESULTS: Modeling had a significant effect on all four dependent measures, with the strongest effects being on amount consumed and blood alcohol concentration. In addition, analyses identified numerous variables that moderate the effect of modeling on alcohol consumption, including the drinking history of the participant, the drinking task used and the nature of the interaction between model and participant. CONCLUSIONS: Results indicated that modeling has a strong effect on alcohol consumption; however, several variables do mediate this effect.

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects.

The purpose of this investigation was to compare the myosin heavy chain (MHC) isoform expression of the triceps brachii muscle and isoinertial, isometric and isokinetic strength indices in competitive bodybuilders (CB, n = 5), recreational resistance trainers (RT, n = 5), endurance-trained rowers (ER, n = 5) and control (C, n = 5) subjects. Muscle tissue samples were analysed for MHC isoform content using 6% sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The CB possessed significantly smaller (P < 0.05) percentage of MHC type IIb proteins [12.92 (SD 7.08)%] than RT [30.08 (SD 6.58)%] ER [31.20 (SD 2.74)%] and C [38.22 (SD 2.95)%] groups (i.e. CB < RT approximately ER < C). While the content of MHC type IIa isoforms did not differ significantly between the two resistance-trained groups [CB = 55.76 (SD 5.38)%; RT = 45.72 (SD 7.8)%], CB presented significantly more type IIa MHC isoforms than ER [42.84 (SD 2.98)%] and C [34.72 (SD 1.57)%] subjects (i.e. CB approximately RT > ER approximately C). The MHC type I protein content did not differ significantly among RT [24.20 (SD 4.89)%] ER [25.38 (SD 1.67)%] and C [27.06 (SD 1.81)%] groups. The CB [31.32 (SD 2.67)%] presented significantly more type I MHC isoforms only in comparison with RT. However, when changes in the percentage of MHC type I isoforms were converted to effect sizes (ES), it appeared that low statistical power rather than the absence of an effect accounted for the nonsignificant differences between CB and other groups (i.e. CB > RT approximately ER approximately C). Significant differences existed in isoinertial strength among the trained athletes (i.e. CB > RT > ER approximately C), while isometric and isokinetic strength were not significantly different among any of the trained groups. However, the ES transformation of data demonstrated that large differences existed between resistance-trained groups and ER for isometric and isokinetic strength (i.e. CB approximately RT > ER approximately C). A statistically significant negative correlation (P < 0.001) was found between MHC type IIb isoforms and isoinertial strength index (r = -0.68). The MHC type IIa proteins were positively related to all the strength measures considered (r = 0.51 0.61; P < 0.001). These data demonstrated different patterns of MHC isoform expression among the different groups of athletes and it is suggested that these differences on occasion may affect the expression of strength.

Effect of cryotherapy on muscle soreness and strength following eccentric exercise.

The purpose of this study was to determine whether a post-exercise cryotherapy protocol could facilitate recovery of elbow flexor strength and reduce the severity of delayed onset muscle soreness following eccentric exercise. Eight resistance-trained males (23 +/- 3 yr) performed 64 eccentric elbow flexions with each arm. One arm was subjected to five, 20 minute immersions in a 5 +/- 1 degree C ice-water bath interspersed by 60 minute rest periods. The non-immersed arm served as the control. A main effect for time was observed for all dependent variables (p < 0.05). Isometric torque (mean SE) decreased from a pre-exercise value of 87.9 +/- 4.5 Nm to 65.2 +/- 4.5 Nm immediately post-exercise. Isokinetic torque at 60 and 300 degrees x s(-1) decreased from 71.0 +/- 3.5 NM and 48.4 +/- 2.8 Nm to 55.8 +/- 3.3 Nm and 39.8 +/- 3.1 Nm, respectively. All torque measures returned to pre-test levels by 72 h. Muscle soreness peaked 48 h post-exercise and was evident until 120 h. Limb volume increased by 200 +/- 18 ml immediately post-exercise (p < 0.05) but was not significantly elevated thereafter. No significant difference between the immersed and control arms were observed for any variable. The result suggest that the use of cryotherapy immediately following damaging eccentric exercise may not provide the same therapeutic benefits commonly attributed to cryotherapy following traumatic muscle injury.

Desistance of husband aggression in the early years of marriage.

Desistance of husband marital aggression was investigated over a 3-year time span. One hundred and eighty-eight couples who had experienced husband aggression in the first year of marriage were followed to the third year of marriage. Overall 23.9% of these husbands had no violence in years 2 and 3. However, desistance rates differed as a function of the type of violence that occurred in year 1. Husbands who had only one incident of minor physical aggression and no severe violence in year 1 were most likely to desist in years 2 and 3 while those who used severe violence in year 1 were least likely to desist. Subsequent analyses showed that wife's depression and dissatisfaction with the partner increased from years 1 to 3 when desistance did not occur.

The influence of high-intensity exercise training on the Wlim-Tlim relationship.

When exercise to exhaustion is performed using at least two different intensities, work to fatigue (Wlim) can be expressed as a linear function of time to fatigue (Tlim). Whereas the slope of this function is related to endurance ability, the y-intercept is associated with the potential to perform high intensity interval exercise. The purpose of the present investigation was to determine the influence of 8-wk intermittent high-intensity exercise training on the y-intercept derived from the Wlim-Tlim relationship. Eight healthy, untrained male students (19.1 +/- 0.6 yr) completed five 60-s bouts of maximal exercise on the cycle ergometer, three times a week, for 8 wk. Seven controls avoided regular activity for the same period. Prior to and immediately following the training period, the Wlim-Tlim relationship, VO2max, and total work completed in five 60-s exercise bouts on the cycle ergometer were determined. Correlational analysis established relationships between the y-intercept and total work accomplished in the interval test pre- (r = 0.90; P < 0.01; N = 15) and post-training (r = 0.92; P < 0.01; N = 15), confirming that the y-intercept is related to the ability to perform exercise of this nature. Moreover, the "anaerobic" energy yield, calculated from total work and oxygen consumed during the interval exercise, was also related to the y-intercept (r = 0.78; P < 0.01). Interval training significantly increased both the y-intercept (P = 0.0015) and total work accomplished in the interval test (P = 0.001), while the slope of the Wlim-Tlim relationship (critical power) remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Endurance training enhances critical power.

The present investigation was conducted to determine whether critical power (CP) assesses the ability to perform continuous aerobic exercise and to determine whether training-induced changes in aerobic endurance are reflected by changes in the slope, but not the y-intercept of the CP function. Twelve healthy, active, but untrained male students (mean age +/- SD = 19.1 +/- 0.8 yr) undertook 8 wk of cycle ergometer endurance training (30-40 min a day, three times a week) at an intensity corresponding to their CP. Six control subjects of similar age and initial training status refrained from regular exercise for the same period. Before and immediately following the training period, each of the 18 participants completed three cycle ergometer tests to determine their CP function, an incremental exercise task to establish their maximal oxygen uptake (VO2max), and 40 min of continuous cycle ergometry at or near their calculated CP. CP was significantly correlated with endurance time at 270 W (r = 0.65, P < 0.05) and with the mean power that could be maintained for 40 min (r = 0.87-0.95, P < 0.01), but overestimated the latter by less than 6%. In response to endurance training, CP increased from a mean of 196 +/- 40.9 W to 255 +/- 28.4 W (31%) (ANCOVA, P < 0.01), while the mean power output maintained for 40 min of exercise increased from 190 +/- 34.5 W to 242 +/- 34.9 W (28%). VO2max increased from 49.2 +/- 7.8 ml.kg-1.min-1 to 53.4 +/- 6.4 ml.kg-1.min-1 (8.5%) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary baroreflex control of forearm vascular resistance after acute blood volume expansion.

We report the stimulus-response characteristics of cardiopulmonary (CP) baroreflex control of forearm vascular resistance (FVR) in young adult male volunteers before and after: 1) blood volume expansion (8 ml/kg infusion of 5% human serum albumin solution, n = 5) and 2) a redistribution of blood volume toward the heart (6 degrees head-down tilt (HDT), n = 6). We assessed the relationship between reflex stimulus (i.e., changes in central venous pressure (CVP] and response (i.e., FVR) during unloading of CP mechanoreceptors with lower body negative pressure (0 to -20 mm Hg). Changes in CVP were estimated from changes in venous pressure of a large peripheral vein of the dependent arm with the subject in the right lateral decubitus position. In all conditions, reflex forearm vasoconstriction occurred in response to a reduction in estimated CVP. The absolute change in FVR per unit of CVP was reduced from -4.24 +/- 1.68 to -2.15 +/- 1.16 units/mm Hg (p less than 0.05) following blood volume expansion but was similar before (-3.34 +/- 0.89 units/mm Hg) and during 6 degrees HDT (-3.30 +/- 0.92 units/mm Hg). The reduced sensitivity of the CP baroreflex following volume expansion was manifested primarily as a smaller FVR response to LBNP (p less than 0.05). Blood volume expansion and 6 degrees HDT increased resting estimated CVP by 1.5 and 0.9 mm Hg, respectively (p less than 0.05) and resting levels of FVR decreased slightly.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise intensity: effect on postexercise O2 uptake in trained and untrained women.

Despite many reports of long-lasting elevation of metabolism after exercise, little is known regarding the effects of exercise intensity and duration on this phenomenon. This study examined the effect of a constant duration (30 min) of cycle ergometer exercise at varied intensity levels [50 and 70% of maximal O2 consumption (VO2max)] on 3-h recovery of oxygen uptake (VO2). VO2 and respiratory exchange ratios were measured by open-circuit spirometry in five trained female cyclists (age 25 +/- 1.7 yr) and five untrained females (age 27 +/- 0.8 yr). Postexercise VO2 measured at intervals for 3 h after exercise was greater (P less than 0.01) after exercise at 50% VO2max in trained (0.40 +/- 0.01 l/min) and untrained subjects (0.39 +/- 0.01 l/min) than after 70% VO2max in (0.31 +/- 0.02 l/min) and untrained subjects (0.29 +/- 0.02 l/min). The lower respiratory exchange ratio values (P less than 0.01) after 50% VO2max in trained (0.78 +/- 0.01) and untrained subjects (0.80 +/- 0.01) compared with 70% VO2max in trained (0.81 +/- 0.01) and untrained subjects (0.83 +/- 0.01) suggest that an increase in fat metabolism may be implicated in the long-term elevation of metabolism after exercise. This was supported by the greater estimated fatty acid oxidation (P less than 0.05) after 50% VO2max in trained (147 +/- 4 mg/min) and untrained subjects (133 +/- 9 mg/min) compared with 70% VO2max in trained (101 +/- 6 mg/min) and untrained subjects (85 +/- 7 mg/min).

The y-intercept of the critical power function as a measure of anaerobic work capacity.

When bouts of muscular work are performed to exhaustion at different intensities, the slope of the regression of maximal work (work limit) on maximal time (time limit) is referred to as critical power (CP). The y-intercept of this function is considered to represent anaerobic work capacity (AWC). The purpose of this investigation was to examine the relationship between the y-intercept from the critical power curve and measures of AWC (total work accomplished, maximal blood lactate and post-exercise venous blood pH) gained from repeated, maximal exercise. Nine male volunteers of moderately high training status (VO2 max 4.45 +/- 0.251/min) completed three cycle ergometer tests to exhaustion (at 300, 350 and 400 W) for the determination of CP. A second cycle ergometer task involved repeated maximal effort (against 0.075 N/kg body mass) over five 1 min periods. Five min of passive recovery separated each exercise bout, at the end of which capillary blood was collected for lactate analysis. On completion of the fifth bout, venous blood was sampled for the determination of blood pH. Total accumulated work provided a performance estimate of AWC which, together with blood lactate and pH, was compared to the y-intercept. Correlation analysis revealed a significant relation between the y-intercept and total work accomplished (r = 0.74; p less than 0.05), while post-exercise venous blood pH was positively related to both the y-intercept (r = 0.92; p less than 0.01) and the accumulated work recorded (r = 0.92; p less than 0.01). No significant correlation between peak blood lactate and work was found (r = 0.16; ns), although a relation between post-exercise venous blood pH and VO2 max was established (r = 0.84; p less than 0.05). The capacity for high intensity interval work was well represented by the y-intercept in active males. Furthermore, the relations between blood pH and both the y-intercept and accumulated work suggest that either improved buffering or a greater contribution of aerobic metabolism to the energy yield may have been responsible for the more successful performances in the interval exercise.

Blood lactate in trained cyclists during cycle ergometry at critical power.

The purposes of this investigation were to determine the validity of critical power (CP) as a measure of the work rate that can be maintained for a very long time without fatigue and to determine whether this corresponded with the maximal lactate steady-state (lass,max). Eight highly trained endurance cyclists (maximal oxygen uptake 74.1 ml.kg-1.min-1, SD 5.3) completed four cycle ergometer tests to exhaustion at pre-determined work rates (360, 425, 480 and 520 W). From these four co-ordinates of work and time to fatigue the regression of work limit on time limit was calculated for each individual (CP). The cyclists were then asked to exercise at their CP for 30 min. If CP could not be maintained, the resistance was reduced minimally to allow the subject to complete the test and maintain a blood lactate plateau. Capillary blood was sampled at 0,5,10,20 and 30 min into exercise for the analysis of lactate. Six of the eight cyclists were unable to maintain CP for 30 min without fatigue. In these subjects, the mean power attained was 6.4% below that estimated by CP. Mean blood lactates (n = 8) reached a steady-state (8.9 mmol.l-1 SD 1.6) during the last 20 min of exercise indicating that CP slightly overestimated lass,max, Individual blood lactates during the last 20 min of exercise were more closely related to the gamma-intercept of the CP curve (r = 0.78, P less than 0.05) than either CP (0.34, NS) or mean power output (r = 0.42, NS).

Duration of protective effect of terbutaline sulfate and cromolyn sodium alone and in combination on exercise-induced asthma.

For subjects with EIA participating in physical activities throughout the day, prolonged duration of protection is desirable. The purpose of this study was to determine whether in EIA a combination of the recommended aerosol doses of the beta 2-adrenergic receptor agonist, terbutaline sulfate (0.5 mg), and cromolyn sodium (disodium cromoglycate; 2 mg) provides longer protection against EIA than either drug alone. On four separate days, following the administration of either placebo, terbutaline alone, cromolyn sodium alone or terbutaline and cromolyn sodium together, 12 subjects (seven men and five women; aged 18 to 28 years) with EIA performed four identical eight minute treadmill runs, each separated by two-hour intervals. Drug treatments were given double-blind, with the order counterbalanced using a Latin-square design. Pulmonary function was recorded before the drug, immediately before and after exercise, and at 3, 4, 5, 6, 7, 10, 15, and 30 minutes after exercise. Inspired ventilation, heart rate, and environmental conditions were monitored during exercise. A two-way analysis of variance was performed to investigate the main effects of time and drug treatment. Results indicated that in comparison with placebo, EIA was significantly reduced by either cromolyn sodium or terbutaline administered up to two hours (p less than 0.01) and by the combination (cromolyn sodium and terbutaline) up to four hours after inhalation (p less than 0.05). No significant differences were found between the combination and terbutaline during the initial two hours (p less than 0.5). We conclude that a combination of beta 2-adrenergic receptor agonist and cromolyn sodium is the treatment of choice for prolonged effective protection from EIA.

Pain and fatigue after concentric and eccentric muscle contractions.

1. Normal subjects performed a step test in which the quadriceps of one leg contracted concentrically while the contralateral muscle contracted eccentrically. 2. Maximal voluntary force and the force: frequency relationship were altered bilaterally as a result of the exercise, the changes being greater in the muscle which had contracted eccentrically. Recovery occurred over 24 h. 3. Electromyographic studies using three sites on each muscle showed an increase in electrical activation during the exercise only in the muscle which was contracting eccentrically. Recovery followed a time course similar to that of the contractile properties. 4. Pain and tenderness developed only in the muscle which had contracted eccentrically. Pain was first noted approximately 8 h after exercise and was maximal at approximately 48 h after exercise, at which time force generation and electrical activation had returned to pre-exercise values. 5. Eccentric contractions cause more profound changes in some aspects of muscle function than concentric contractions. These changes cannot be explained in simple metabolic terms, and it is suggested that they are the result of mechanical trauma caused by the high tension generated in relatively few active fibres during eccentric contractions.

"Biorhythms" and men's track and field world records.

The claims that athletic performance, like all human behavior, are governed by three invariant "biorhythms" were tested for all men's metric world records in track and field from 1913-1977 (N = 700). Outstanding performances are said to occur during positive cycle phases; and poor performances, errors of judgment, and accidents, during the negative phases and particularly at crossover points (critical days). "Biorhythm" amplitudes were calculated, and a chi-square (X2) analysis was used to compare the frequencies of records occurring in the positive, negative, and critical phases of each cycle with a random model. The phase-distribution of records within each individual cycle fit the random model (X2 less than or equal to 2.22, P greater than 0.30). The combined effects of the three cycles, determined from the mean "biorhythm" amplitude (X2 = 1.30, P greater than 0.20) and the number of cycles in each phase (X2 = 3.50, P greater than 0.30), also showed no significant departure from the expected frequencies. The number of records broken on single or multiple critical days was as expected from the number of critical days in ech cycle (X2 = 3.37, P greater than 0.15). These data reinforce our previous study on Australian records and the preponderance of acceptable published research into sports, accidents, and medical data in that they provide no evidence of the existence or effects of "biorhythms."

The role of physical activity in the control of obesity.

An exercise programme is an important part of the management of the obese patient. Exercise may increase both the specific dynamic action of food and the post-exercise metabolic rate, in addition to its direct caloric cost. Moderate daily exercise aids regulation of the appetite and may reduce the voluntary caloric intake of otherwise sedentary persons. Post-prandial activity may utilize more calories; therefore an adequate breakfast and avoidance of late night eating may be effective in weight control. A better tolerated and more nutritious diet may be allowed, and lean body weight better preserved, by combining exercise with a dietary programme. Regular exercise may also reduce some of the more serious life-threatening complications of obesity and poor dietary habits, allowing greater freedom in the pursuit of other pleasures.