Arvydas Stasiulis

Cooling leg muscles affects dynamics of indirect indicators of skeletal muscle damage

Objectives: To determine the effect of leg immersion in cold water after stretch-shortening exercise (SSE) on the time-course of indirect indicators of exercise-induced muscle damage (EIMD). Methods: Twenty healthy untrained men twice performed SSE consisting of 100 drop jumps (DJs) from 0.75 m height performed with maximal intensity with an interval of 20 s between the jumps. DJs were performed with counter-movement to 90 degrees angle in the knee and with immediate maximal rebounds. After SSE the subjects legs immediately, as well as after 4 h, 8 h and 24 h, were immersed into a bath filled with water at 15 ± 1 ◦ C. Quadriceps muscle voluntary contraction force (MVCF) and force evoked by electrostimulation (ESF) at different frequencies and at different muscle length, jump height (H), muscle soreness and creatine kinase (CK) activity in the blood were measured before SSE, immediately after SSE and within 72 h of recovery. Results: After stretch-shortening exercise MVCF, ESF and H were significantly ( P< 0.001) decreased and were not restored even after 72 h in the group that did not receive the cooling. Within 24-48 h after SSE the subjects felt great muscle pain and CK activity in their blood was increased ( P< 0.001). The cooling significantly accelerated the disappearance of all these indicators, except for low-frequency fatigue, but only within 24-72 h after SSE. Conclusion: Cold water immersion after SSE accelerates the disappearance of the majority of indirect indicators of EIMD.

Concentric myocardial hypertrophy after one-year of increased training volume in experienced distance runners

Objectives: As evidence on the predominant type of cardiac hypertrophy due to endurance running training is inconsistent, the aim of this study was to investigate the effect of increased training volume on echocardiographic variables of distance runners. Methods: Twenty three adult, experienced, male distance runners underwent standard two dimensionally guided M mode and Doppler echocardiography before and after a one year period during which they were randomly allocated to either control (n  =  11) or intervention (n  =  12) groups. The intervention group increased their training volume from (mean (SD)) 8.0 (3.0) to 12.5 (3.9) hours/week without increasing the intensity, and the controls changed neither training parameter. Results: In the intervention group, training induced an increase in left ventricular (LV) mass (from 240.4 (53.8) to 279.5 (60.6) g, p<0.001) and LV mass index (from 126.7 (28.2) to 147.6 (32.3) g/m2, p<0.001) mainly due to an increase in end diastolic interventricular septum (from 10.4 (1.8) to 11.5 (1.7) mm, p<0.01) and LV posterior wall thickness (from 10.4 (1.6) to 11.5 (1.6) mm, p<0.001). No significant changes in LV internal diameter or measured indices of LV function occurred (p>0.05). The sum of the right ventricular diameter and wall thickness was greater after the increased volume training (p<0.05). None of the variables changed significantly in the control group (p>0.05). Conclusions: In experienced, subelite distance runners, further increasing the training volume results in concentric cardiac hypertrophy.

Strongmen sport is associated with larger absolute heart size and impaired cardiac relaxation.

Venckunas, T, Vasiliauskas, D, Marcinkeviciene, JE, Grizas, V, Stasiulis, A, and Malkova, D. Strongmen sport is associated with larger absolute heart size and impaired cardiac relaxation. J Strength Cond Res 25(10): 2919–2925, 2011—This study was carried out to compare cardiac structure and function and blood lipids among Strongmen, sedentary controls, and marathoners. Echocardiography was performed, and endothelial function, blood lipids and maximal oxygen uptake were measured in 27 Caucasian adult men (8 Strongmen, 10 marathoners, 9 controls). Absolute cardiac size parameters such as left ventricular (LV) diameter and wall thickness of Strongmen were higher (p < 0.05), but relative (body surface area indexed) parameters were not different between controls and Strongmen. In Strongmen, the relative LV diameter (p < 0.05), wall thickness (p < 0.001), and LV mass index (p < 0.01) were lower than in marathoners. The absolute but not relative right ventricular diameter was larger in Strongmen as compared with controls, whereas all of the measured relative cardiac size parameters were higher in marathoners as opposed to in controls. The endothelial function and the ratio of wall thickness to chamber diameter were similar among the groups (p > 0.05). Maximal oxygen uptake of Strongmen was lower than in controls (p < 0.05) and marathoners (p < 0.001). Global diastolic LV function of Strongmen was impaired in comparison to controls (p < 0.05) and marathoners (p < 0.05). Plasma lipids were not different between Strongmen and sedentary controls, but in comparison to runners, Strongmen had higher low-density lipoprotein-cholesterol (p < 0.05) and lower high-density lipoprotein cholesterol (p < 0.01). Participation in Strongmen sport is associated with higher absolute but not relative cardiac size parameters, impaired myocardial relaxation, and low cardiorespiratory fitness. Therefore, Strongmen may demand greater attention as an extreme group of athletes with regard to cardiovascular risk.

PHYSIOLOGICAL RESPONSES AND ENERGETICS OF COMPETITIVE GROUP EXERCISE IN FEMALE AEROBIC GYMNASTS WITH DIFFERENT LEVELs OF PERFORMANCE.

This study investigated the aerobic fitness and physiologic and energetic responses during competitive exercise in aerobic gymnasts. The gymnasts performed a graded treadmill test and competitive group exercises. Energetic response was calculated from oxygen uptake and blood lactate changes. Peak oxygen uptake was similar in International (M = 45.4m · kg−1 · min.−1, SD = 3.9) and National (M = 44.7ml · kg−1 · min.−1, SD = 3.6) level groups. During their competitive routines, total energy and the fractions of aerobic, anaerobic alactic, and anaerobic lactic energy were 1,847.7 (SD = 293.9) and 1,747.3 (SD = 196.7) J · kg−1, 53.5% (SD = 3.1) and 60.3% (SD = 6.1), 25.4% (SD = 5.9) and 21.4% (SD = 5.2), and 21.1% (SD = 5.8) and 18.3% (SD = 4.5) in international and national level athletes, respectively (p > .05). The contribution of anaerobic energy was higher in the international level group (p = .03). It is concluded that the aerobic fitness and absolute energetic and physiological responses of athletes during competitive activities were not different between the aerobic gymnasts groups with different levels of performance, but a higher relative contribution of anaerobic energy was observed in the group with a higher performance level.

P-87 Acvr1b rs2854464 is associated with quantitative measures of strength/power in lithuanian athletes and controls

Genetic variation is known to account for a large portion of the variation in muscle mass and strength/power in humans. However, few polymorphisms have been conclusively linked with these phenotypes. The myostatin signalling pathway is a source of potential candidates due to its involvement in muscle growth. Variation in myostatin itself has been shown to relate to muscle mass in humans; however, myostatin variation is rare in humans. Other studies have related variation in ACVR1B, a component of the myostatin signalling pathway, to strength/power phenotypes or to athlete status. However, this work still needs replication in large well phenotyped cohorts containing elite athletes. This study aims to replicate previous studies on the relationship between variation in the ACVR1B (rs2854464) G/A polymorphism and strength/power related phenotypes in well phenotyped Lithuanian athletes and controls. Participants DNA samples were from the GELAK cohort. This is comprised of 407 Lithuanians: 84 endurance athletes (END), 126 sprint-strength-power (SSP) and 197 controls (CON). Phenotypes related to stature (height, body mass, BMI), strength (isokinetic peak torque in left and right legs at 30 degrees per second), power (Wingate) and speed (30 m sprint). Genotypes were determined using bespoke RFLPs. Genotype distributions were compared by Chi squared. Odds ratios are reported as mean (lower to upper 95% confidence limits). Associations were established using GLM-ANOVA in Minitab. All GLM analyses were corrected for athlete group and age in months. The control sample was in Hardy-Weinberg equilibrium. Allele frequencies were similar to those reported in 1000 Genomes database. ACVR1B rs2854464 genotype distributions differed between SSP v END (p = 0.015) groups only. AA homozygotes were 2.16 (1.22 to 3.81) times more likely to be END than SSP (p = 0.007). After correction for age and athlete group, ACVR1B rs2854464 variation associated with body mass (p = 0.042, V = 1.36%), BMI (p = 0.016, V = 1.76%) and Wingate total anaerobic work (p = 0.021, V = 1.72%) but not with height, isokinetic peak torque, Wingate peak power or 30 m sprint speed. In all significant relationships, AA homozygotes were significantly weaker than GA heterozygotes. Variation in ACVR1B rs2854464 differs between endurance and strength athletes. It also relates to body mass and quantitative measurements of muscle function. However, in contrast to previous work, carriers of the A-allele are less likely to be strength/power athletes and even after correction for age and athlete group, carriers of the A-allele are still likely to have lower body mass and have lower capacity for anaerobic work. References Windelinckx, et al. (2011) Comprehensive fine mapping of chr12q12-14 and follow-up replication identify activin receptor 1B (ACVR1B) as a muscle strength gene. Eur J Hum Gen 19:208–215. Voisin, et al. (2016) ACVR1B rs2854464 Is Associated with Sprint/Power Athletic Status in a Large Cohort of Europeans but Not Brazilians. PLoS One 11(6):e0156316.