High-intensity high-volume swimming induces more robust signaling through PGC-1α and AMPK activation than sprint interval swimming in <i>m. triceps brachii</i>

We aimed to test whether high-intensity high-volume training (HIHVT) swimming would induce more robust signaling than sprint interval training (SIT) swimming within the m. triceps brachii due to lower metabolic and oxidation. Nine well-trained swimmers performed the two training procedures on separate randomized days. Muscle biopsies from m. triceps brachii and blood samples were collected at three different time points: a) before the intervention (pre), b) immediately after the swimming procedures (post) and c) after 3 h of rest (3 h). Hydroperoxides, creatine kinase (CK), and lactate dehydrogenase (LDH) were quantified from blood samples, and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and the AMPKpTHR172/AMPK ratio were quantified by Western blot analysis. PGC-1α, sirtuin 3 (SIRT3), superoxide-dismutase 2 (SOD2), and vascular endothelial growth factor (VEGF) mRNA levels were also quantified. SIT induced a higher release of LDH (

Futsal match-related fatigue affects running performance and neuromuscular parameters but not finishing kick speed or accuracy

Purpose: The aim of the present study was to investigate the influence of futsal match-related fatigue on running performance, neuromuscular variables, and finishing kick speed and accuracy. Methods: Ten professional futsal players participated in the study (age: 22.2±2.5 years;) and initially performed an incremental protocol to determine maximum oxygen uptake (VO2max : 50.6±4.9 mL.kg-1.min-1). Next, simulated games were performed, in four periods of 10 min during which heart rate and blood lactate concentration were monitored. The entire games were video recorded for subsequent automatic tracking. Before and immediately after the simulated game, neuromuscular function was measured by maximal isometric force of knee extension, voluntary activation using twitch interpolation technique, and electromyographic activity. Before, at half time, and immediately after the simulated game, the athletes also performed a set of finishing kicks for ball speed and accuracy measurements. Results: Total distance covered (1st half: 1986.6±74.4 m; 2nd half: 1856.0±129.7 m – P=0.00) and distance covered per minute (1st half: 103.2±4.4 m.min-1; 2nd half: 96.4±7.5 m.min-1 – P=0.00) demonstrated significant declines during the simulated game, as well as maximal isometric force of knee extension (Before: 840.2±66.2 N; After: 751.6±114.3 N – P=0.04) and voluntary activation (Before: 85.9±7.5%; After: 74.1±12.3% – P=0.04), however ball speed and accuracy during the finishing kicks were not significantly affected.Conclusion: Therefore, we conclude that despite the decline in running performance and neuromuscular variables presenting an important manifestation of central fatigue, this condition apparently does not affect the speed and accuracy of finishing kicks

Cancer in first-degree relatives and risk of testicular cancer in Denmark

Familial aggregation of testicular cancer has been reported consistently, but it is less clear if there is any association between risk of testicular cancer and other cancers in the family. We conducted a population based case-control study to examine the relationship between risk of testicular cancer and 22 different cancers in first-degree relatives. We included 3297 cases of testicular cancer notified to the Danish Cancer Registry between 1991 and 2003. 6594 matched controls were selected from the Danish Civil Registration System, which also provided the identity of 40,104 first-degree relatives of case and controls. Familial cancer was identified by linkage to the Danish Cancer Registry, and we used conditional logistic regression to analyse whether cancer among first-degree relatives was associated with higher risk of testicular cancer. Rate ratio (RR) for testicular cancer was 4.63 (95% CI: 2.41–8.87) when a father, 8.30(95% CI: 3.81–18.10) when a brother and 5.23 (95% CI: 1.35–20.26) when a son had testicular cancer compared with no familial testicular cancer. Results were similar when analyses were stratified by histologic subtypes of testicular cancer. Familial Non-Hodgkin lymphoma and oesophageal cancer were associated with testicular cancer; however these may be chance findings. The familial aggregation of testicular and possibly other cancers may be explained by shared genes and/or shared environmental factors, but the mutual importance of each of these is difficult to determine

Map of space-only clusters of non-Hodgkin lymphoma in Denmark.

<p>One area showing statistically significant clustering of non-Hodgkin lymphoma cases (area no. 8), and two areas showing borderline clustering (area no. 9 and 10), based on spatial scan statistics of SaTScan and a maximum cluster size of 10% of the total population, using year when clusters were suggested by Q-statistics. None of these cluster regions were consistently found with both control groups.</p

Map of space-time clusters of non-Hodgkin lymphoma in Denmark adjusted for potential confounding factors.

<p>Three areas showing statistically significant clustering of non-Hodgkin lymphoma cases in Denmark identified with Q-statistics, based on 15 nearest neighbours and adjusted analyses. The circles indicate the extent of the clusters, not the number of cases comprising each cluster. None of these cluster regions were consistently found with both control groups.</p

Human muscular mitochondrial fusion in athletes during exercise

The main objective of this work was to investigate whether mitochondrial fusion occurs in the skeletal muscle of well-trained athletes in response to high-intensity exercise. Well-trained swimmers (n = 9) performed a duration-matched sprint interval training (SIT) and high-intensity high-volume training (HIHVT) session on separate days. Muscle samples from triceps brachii were taken before, immediately after, and 3 h after the training sessions. Transmission electron microscopy (TEM) was applied to assess mitochondrial morphology. Moreover, expression of genes coding for regulators of mitochondrial fusion and fission were assessed by real-time quantitative PCR. In addition, mitofusin (MFN)2 and optic atrophy 1 (OPA1) were quantified by Western blot analysis. TEM analyses showed that mitochondrial morphology remained altered for 3 h after HIHVT, whereas SIT-induced changes were only evident immediately after exercise. Only SIT increased MFN1 and MFN2 mRNA expression, whereas SIT and HIHVT both increased MFN2 protein content 3 h after exercise. Notably, only HIHVT increased OPA1 protein content. Mitochondrial morphologic changes that suggest fusion occurs in well-adapted athletes during exercise. However, HIHVT appears as a more robust inducer of mitochondrial fusion events than SIT. Indeed, SIT induces a rapid and transient change in mitochondrial morphology.-Huertas, J. R., Ruiz-Ojeda, F. J., Plaza-Díaz, J., Nordsborg, N. B., Martín-Albo, J., Rueda-Robles, A., Casuso, R. A. Human muscular mitochondrial fusion in athletes during exercise

Map of space-time clusters of non-Hodgkin lymphoma in Denmark.

<p>Four areas showing statistically significant clustering of non-Hodgkin lymphoma cases in Denmark identified with Q-statistics, based on 15 nearest neighbours and unadjusted analyses. The circles indicate the extent of the clusters, not the number of cases comprising each cluster. None of these cluster regions were consistently found with both control groups.</p