It has been postulated that additional adiposity has a negative effect on performance in heterogeneous groups of runners. Previous studies have not tested this hypothesis in homogeneous groups of elite runners. The purpose of this study was to determine whether the sum of skinfold thicknesses and specific single skinfold sites were related to competitive running performance in homogeneous groups of male and female elite athletes. In total, 184 top-class runners (130 males and 54 females) volunteered to participate in the study. Skinfolds were measured at the following sites: biceps, triceps, subscapular, pectoral, iliac crest, abdominal, front thigh and medial calf. Runners were classified into groups in accordance with their best performance times. Correlation analysis and partial correlation coefficients that controlled for age and weight were applied to each single skinfold, the sum of six skinfolds (excluding biceps) and the extremity (sum of triceps, front thigh, medial calf) to trunk (sum of subscapular, iliac crest, abdominal) ratio and performance. Performance was rated by the scoring procedures of the International Amateur Athletics Federation. In male runners, the pectoral, iliac crest, abdominal, biceps, triceps, subscapular skinfolds and the sum of six skinfolds were not associated with performance score for any of the distances. High correlations were found between the front thigh (r = 0.78, P = 0.000) and medial calf (r = 0.55, P = 0.018) skinfolds and 1500 m run time, and between the front thigh (r = 0.59, P = 0.014) and medial calf (r = 0.57, P = 0.017) skinfolds and 10,000 m run time. In female runners, the front thigh and medial calf skinfolds were highly correlated with 400 m run time (r = 0.71, P = 0.022 and r = 0.81, P = 0.005, respectively). The results of this study indicate that skinfold thicknesses in the lower limb are positively associated with running time over several distances, and may be a useful predictor of athletic performance.

Numerous studies have observed cardiac biomarker release with prolonged exercise. Despite this, we are unsure as to the constituent aspects of any given exercise bout that may be important in promoting cardiac biomarker release. This study examined the influence of exercise duration and intensity on the appearance of cardiac biomarkers. Twenty-one subjects ran for 45, 90 and 180 min at 85% and 95% of their individual anaerobic threshold on six different days randomized. Cardiac troponin I (cTnI) and N-terminal pro-brain natiuretic peptide (NT-proBNP) were assayed from blood samples collected before, 30 min and 3 h post-exercise. NT-proBNP was elevated after all exercise trials (range before: 21-32; range post: 38-67 ng/L). Peak post-exercise concentrations of NT-proBNP were associated with exercise duration (P=0.049), but not exercise intensity (P=0.451). cTnI was elevated after all exercise trials (range before: 0.007-0.011; range post: 0.008-0.021 μg/L). Peak post-exercise concentrations of cTnI were associated with exercise duration (P=0.003) and intensity (P=0.037). Data suggest that while both cTnI and NT-proBNP increased after all exercise trials, the mediating effect of duration influenced both NT-proBNP and cTnI while intensity influenced only cTnI.

An exercise-associated increase in hs-cTnT and NT-proBNP occurred in response to a 60-minute maximal swimming test that was independent of pubertal status/adolescent vs adults. The present data also suggests that baseline and postexercise hs-cTnT values are higher in male compared with female, with no sex differences in NT-proBNP values.

We evaluated the influence of a 14-wk endurance running program on the exercise-induced release of high-sensitivity cardiac troponin T (hs-cTnT) and NH2-terminal pro-brain natriuretic peptide (NT-proBNP). Fifty-eight untrained participants were randomized to supervised endurance exercise (14 wk, 3-4 days/wk, 120-240 min/wk, 65-85% of maximum heart rate) or a control group. At baseline and after the training program, hs-cTnT and NT-proBNP were assessed before and 5 min, 1 h, 3 h, 6 h, 12 h, and 24 h after a 60-min maximal running test. Before training, hs-cTnT was significantly elevated in both groups with acute exercise (P < 0.0001) with no between-group differences. There was considerable heterogeneity in peak hs-cTnT concentration with the upper reference limit exceeded in 71% of the exercise tests. After training, both baseline and postexercise hs-cTnT were significantly higher compared with pretraining and the response of the control group (P = 0.008). Acute exercise led to a small but significant increase in NT-proBNP, but this was not mediated by training (P = 0.121). In summary, a controlled endurance training intervention resulted in higher pre- and postexercise values of hs-cTnT with no changes in NT-proBNP.

Background and aims To determine the relationship between the risk of exercise addiction (REA) and health status in amateur endurance cyclists. Methods In 859 (751 men and 108 women) cyclists and 718 inactive subjects (307 men and 411 women), we examined the REA (Exercise Addiction Inventory), training status (volume, frequency, experience, and performance), socioeconomic status, quality of life (QoL) (SF-12), quality of sleep (Pittsburgh Sleep Quality Index), anxiety and depression (Hospital Anxiety and Depression Scale), and cardiometabolic risk: body mass index, physical activity (International Physical Activity Questionnaire), physical condition (International Fitness Scale), adherence to the Mediterranean diet (Mediterranean Diet Adherence Screener), alcohol and tobacco consumption. ResultsIn total, 17% of the cyclists showed evidence of REA and 83% showed low REA. REA occurred independent of age, sex, training, and socioeconomic status (all ps > .05). Regardless of REA, the cyclists displayed a better physical QoL and a lower cardiometabolic risk than the inactive subjects (all ps < .05). The cyclists with REA displayed worse values of mental QoL, quality of sleep, and anxiety than cyclists with low REA (all ps < .05). The REA group had better values of mental QoL and anxiety and similar values of quality of sleep than the inactive subjects. The differences in mental QoL between the REA and low REA groups were significantly greater in women (p = .013). There was no Addiction × Sex interaction in the other analyzed variables.ConclusionOur results suggest that an increased prevalence of REA limits the benefits that amateur endurance cycling has on mental health and quality of sleep.