Eduard Bol

Injuries in high-risk persons and high-risk sports A longitudinal study of 1818 school children

In this Dutch population-based study we attempted to determine the incidence and severity of sports injuries occurring during different kind of sports in a longitudinal way. The study included 1818 school children aged 8 to 17 years. Over a period of 7 months, 399 sports injuries were reported in 324 youngsters. The most common types of injuries were contusions (43%) and sprains (21 %). Medical attention was needed in 25% of all cases. Young basketball, handball and korfball play ers had a nearly 100% chance of suffering one sports injury per year. Volleyball especially had a high inci dence rate in practice (6.7 in 1000 hours). Although physical education classes had a low incidence rate, there were significantly more fractures on the upper limb. Etiologically, sports-related factors were much more important than personal-bound factors. The in jured youths spent more time in practice than the noninjured ones, both in organized and nonorganized sports (P < 0.001). High-risk sports were characterized by contact, a high jump rate, and indoor activities. These three factors explained 78% of the total variance. The contact versus noncontact factor accounted for 48% of the medically treated injuries. An additional goal of this study was to explore the seasonal influence as an extrinsic environmental factor. We found that the duration of injury was increased in the spring (P < 0.05). Specific preventive measures were formulated in order to reduce the number of new and recurring inju ries and a proposal was made to implement injury prevention in school curriculums.

Gastrointestinal symptoms in long-distance runners, cyclists, and triathletes: prevalence, medication, and etiology.

ObjectiveThe aim of this study was to determine the prevalence of exercise-related gastrointestinal (GI) symptoms and the use of medication for these symptoms among long-distance runners, cyclists, and triathletes, and to determine the relationship of different variables to GI symptoms.MethodsA mail questionnaire covering the preceding 12 months was sent to 606 well-trained endurance type athletes: 199 runners (114 men and 85 women), 197 cyclists (98 men and 99 women), and 210 triathletes (110 men and 100 women) and sent back by 93%, 88%, and 71% of these groups, respectively. Symptoms were evaluated with respect to the upper (nausea, vomiting, belching, heartburn, chest pain) or lower part of the GI tract (bloating, GI cramps, side ache, urge to defecate, defecation, diarrhea). For statistical analysis, Mann-Whitney U test, Fisher exact test, or Student t test were used.ResultsRunners experienced more lower (prevalence 71%) than upper (36%) GI symptoms during exercise. Cyclists experienced both upper (67%) and lower (64%) symptoms. Triathletes experienced during cycling both upper (52%) and lower (45%) symptoms, and during running more lower (79%) than upper (54%) symptoms. Bloating, diarrhea, and flatulence occurred more at rest than during exercise among all subjects. In general, exercise-related GI symptoms were significantly related to the occurrence of GI symptoms during nonexercise periods, age, gender, diet, and years of training. The prevalence of medication for exercise-related GI symptoms was 5%, 6%, and 3% for runners, cyclists, and triathletes, respectively.ConclusionsLong-distance running is mainly associated with lower GI symptoms, whereas cycling is associated with both upper and lower symptoms. Triathletes confirm this pattern during cycling and running. The prevalence of medication for exercise-related GI symptoms is lower in the Netherlands in comparison with other countries, in which a prevalence of 10–18% was reported. More research on the possible predisposition of athletes for GI symptoms during exercise is needed.

Effect of exercise training on quality of life in patients with chronic heart failure

The effect of exercise training on quality of life and exercise capacity was studied in 67 patients with mild to moderate chronic heart failure (CHF; age: 65.6+/-8.3 years; left ventricular ejection fraction: 26.5+/-9.6%). Patients were randomly allocated to either a training group or to a control group. After intervention a significantly larger decrease in Feelings of Being Disabled (a subscale of the Heart Patients Psychological Questionnaire) and a significantly larger increase in the Self-Assessment of General Well-Being (SAGWB) were observed in the training group. Exercise time and anaerobic threshold were increased in the training group only. The increase in exercise time was related to both Feelings of Being Disabled and SAGWB. We conclude that supervised exercise training improves both quality of life and exercise capacity and can be safely performed by chronic heart failure patients.

Gastrointestinal problems as a function of carbohydrate supplements and mode of exercise.

The aim of the study was to examine prevalence and duration/seriousness of gastrointestinal (GI) problems as a function of carbohydrate-rich (CHO) supplements and mode of exercise. The relationship between GI problems and a variety of physiological and personal factors (age, exercise experience) was also examined. Thirty-two male tri-athletes performed three experimental trials at 1-wk intervals, each trial on a different supplement: a conventional, semisolid supplement (S; 1.2 g CHO, 0.1 g protein, and 0.02 g fat.kg BW-1 x h-1); an almost isocaloric fluid supplement (F; 1.3 g CHO.kg BW-1 x h-1, no fat, no protein); and a fluid placebo (P). The 3 h of exercise started at 75% VO2max and consisted of alternately cycling (bouts 1 and 3) and running (bouts 2 and 4). GI symptoms were monitored by a questionnaire. Analysis of variance revealed that nausea lasted longer with P as compared with S (P < 0.05). Bloating lasted longer during bout 3 with P as compared with F and S (P < 0.05). Accounting for confounding factors, most GI symptoms occurred more frequently and lasted longer during running than during cycling. Multiple regression analysis revealed significant relationships between nausea and urge to defecate, between an urge to defecate, GI cramps and flatulence, and between belching and side ache. From all other factors energy depletion, CHO malabsorption, exercise intensity, exercise experience, and age were significantly related to GI symptoms during the exercise.

Exercise training in elderly patients with chronic heart failure.

BackgroundPhysical training currently constitutes an important part of treatment of heart failure patients. So far, no data are available on the effects of regular exercise in elderly (aged > 65 years) heart failure patients. MethodsIn a prospective trial, patients with chronic heart failure (New York Heart Association class II and III) were randomly assigned to a training group and a control group. Patients in the training group performed additional exercises three times a week, while patients in the control group continued regular treatment. To analyse the influence of age, both groups were subdivided into subjects younger than and older than 65 years. The effect of training on exercise parameters was evaluated by means of a treadmill test. Quality of life aspects were evaluated with the help of the Heart Patients Psychological Questionnaire and a single-question Self Awareness of General Well-Being test. ResultsComparison of changes between groups revealed that training increased the duration of the exercise test and improved aspects of quality of life in the trained patients aged both younger than and older than 65 years. ConclusionExercise training is equally effective in patients aged younger than and older than 65 years.

Relationship Between Circulating Levels of Sex Hormones and Insulin-Like Growth Factor-1 and Fluid Intelligence in Older Men

The relationship was investigated between baseline serum levels of total testosterone (T), free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), estradiol (E 2 ), sex hormone–binding globulin (SHBG), insulin-like growth factor-1 (IGF-1) and cognitive functioning in 25 healthy older men (mean age 69.1 years). Cognitive tests concerned measures not sensitive to aging (crystallized intelligence), and measures sensitive to aging (fluid intelligence and verbal long-term memory). Partial correlation coefficients (controlled for level of education) revealed significant associations of total T (r =- .52, p = .009), SHBG (r =- .59, p = .002) and IGF-1 (r = .54, p = .007) with the composite measure of fluid intelligence test performance, but not with crystallized intelligence, nor verbal long-term memory. Stepwise hierarchical regression analysis with the composite measure of fluid intelligence as the dependent variable showed that the contributions of SHBG, total T, and IGF-1 were not additive.The relationship was investigated between baseline serum levels of total testosterone (T), free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), ESTRADIOL (E2), sex hormone-binding globulin (SHBG), insulin-like growth factor-1 (IGF-1) and cognitive functioning in 25 healthy older men (mean age 69.1 years). Cognitive tests concerned measures not sensitive to ageing (crystallized intelligence), and measures sensitive to ageing (fluid intelligence and verbal long-term memory). Partial correlation coefficients (controlled for level of education) revealed significant associations of total T (r = -.52, p = -.009), SHBG (r - .59, p = .002) and IGF-1 (r = .54, p = .007) with the composite measure of fluid intelligence test performance, but not with crystallized intelligence, nor verbal long-term memory. Stepwise hierarchical regression analysis with the composite measure of fluid intelligence as the dependent variable showed that the contributions of SHBG, total T, and IGF-1 were not additive.

Cardiopulmonary exercise parameters in relation to all-cause mortality in patients with chronic heart failure

In this study we analysed the all-cause mortality over a period of maximal 6 years in 60 male patients (age: 63.4+/-8.3 years, mean+/-S.D.), suffering from chronic heart failure with resting left ventricular ejection fraction and E/O2 slope as independent factors. We assessed functional NYHA class (II: n=36, III: n=24), radionuclide left ventricular ejection fraction (29.2+/-10.4%) and peak values of heart rate, O2, CO2, E, anaerobic threshold and exercise duration with an incremental work load test on the treadmill. O2 relative to E was based on the individual slopes of the regression of O2 on E during the first 6 min of exercise. These slopes with other exercise-related variables and factors such as etiology, medication, and NYHA class were analysed with a Coxs Regression Method. A survival time analysis (Kaplan-Meier survival curve) was done to establish the influence of E/O2 slope and left ventricular ejection fraction (both split into above and below median values), as well as their interaction, on survival. From all investigated exercise-related variables. E/O2 slope is the most powerful variable regarding prediction of all-cause mortality in our group of chronic heart failure patients. Concerning risk stratification, the subgroup (n=18) with a relatively high left ventricular ejection fraction (>28%) and flat E/O2 slope (<27.6) had most survivors (77.8%) after about 3 years, while the subgroup (n=12) with a relatively high left ventricular ejection fraction (>28%), but a steep E/O2 slope (>27.6) had least survivors (33.3%). This difference in percentage is highly significant (P=0.0025). The fact that E/O2 slope and left ventricular ejection fraction show comparable main and interaction effects between measures of exercise tolerance (e.g., anaerobic threshold, peak O2, exercise duration) on the one hand, and all-cause mortality on the other, suggests the existence of common sources of variance. Based on our analysis, it is unlikely that effects on all-cause mortality are mediated through phenomena related to exercise tolerance. Therefore, we hypothesize that the effects on exercise tolerance and all-cause mortality both depend on common factors, which cause both cardiac and peripheral organ (c.q. muscular) dysfunctions. Moreover, this study clearly shows that E/O2 slope during incremental exercise is an important prognostic marker for risk stratification in chronic heart failure patients, NYHA class II and III.

Direct assessment of extracellular water volume by the bromide‐dilution method in growth hormone‐deficient adults*

Abstract. Body composition and water content were assessed in 36 growth hormone deficient (GHD) patients (M:23, F:13) and 14 controls (M:7, F:7) using anthropometry, hydrodensitometry, bioelectri‐cal impedance measurement and the bromide‐dilution method, with which extracellular water volume can be measured directly. GHD patients, compared to controls, did not differ in extracellular water volume, in hydration state and water distribution. A higher BMI (P=0002) and a higher body fat mass (P < 0.0001) were found in the patients. Based on circumference measurements, the GHD patients had a higher waist/ hip ratio (P = 0.0001). This study shows that GHD patients, in comparison with healthy controls, have a normal extracellular water volume. The finding that extracellular water volume is within the normal range in GHD patients may be clinically relevant as it is well known that in the first months after initiating GH‐replacement therapy, most patients have signs and symptoms of excessive water retention.

Duodenal motility during a run-bike-run protocol: the effect of a sports drink.

Objective To examine the effect of a sports drink during strenuous exercise on duodenal motility and gastrointestinal symptoms. Methods In a cross-over design, seven male triathletes performed two 170-min run–bike–run tests at about 70% peak oxygen uptake (O2peak), with either a 7% carbohydrate (CHO) sports drink or tap water. Antroduodenal motility (phase III of the migrating motor complex; MMC) was measured with an ambulant manometry system. The effect of the two exercise trials on the first appearance of the MMC was assessed in the postprandial period. Results Exercise heart rate, percentage O2peak and loss of body mass did not differ significantly between the two trials. After the start of the exercise, the expected time before the first phase III occurrence, based on the actual energy intake of the last meal in the morning before exercise (1048 ± 294 kcal), a fixed gastric emptying rate and a lag phase for solid food, was 183 ± 113 min (mean ± standard deviation [SD]). The real time period between the start of the exercise with CHO and the first phase III was 63 ± 61 min, which was significantly shorter than that observed with tap water (152 ± 59 min). Both real time periods were shorter than the expected time period of 183 ± 113 min (P < 0.05). During exercise, the number of subjects with a phase III was higher with CHO than with tap water (n = 6 v. n = 1;P < 0.05). Also, the median number of phases III per hour with CHO was higher than with tap water (0.4 v. 0.0;P < 0.05). During cycling, significantly more phases III per hour (0.9) were measured than during running (0.2). All subjects reported one or more gastrointestinal symptoms during exercise, however, without a clear association with the mode of exercise or supplementation. Conclusions Prolonged exercise results in gastrointestinal symptoms and a significant interruption of postprandial motility. Only the latter phenomenon depends on the mode of exercise and supplementation.

Determinants of maximal exercise performance in chronic heart failure.

Background Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function. Aim To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance. Design In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan. Results Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r = −0.22), gender (r = 0.45), fat free mass (FFM) (r = 0.51), quadriceps muscle area (r = 0.73), hamstrings muscle area (r = 0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r = 0.71) and isometric strength (r = 0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax. Conclusion Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.