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Purpose: We evaluated (1) whether participating in middle- and long-distance running races augments muscle soreness, oxygen cost, respiration, and exercise exertion during subsequent running, and (2) if post-race menthol application alleviates these responses in long-distance runners. Methods: Eleven long-distance runners completed a 1500-m race on day 1 and a 3000-m race on day 2. On day 3 (post-race day), either a 4% menthol solution (Post-race menthol) or a placebo solution (Post-race placebo) serving as a vehicle control, was applied to their lower leg skin, and their perceptual and physiological responses were evaluated. The identical assessment with the placebo solution was also conducted without race participation (No-race placebo). Results: The integrated muscle soreness index increased in the Post-race placebo compared to the No-race placebo (P < 0.001), but this response was absent in the Post-race menthol (P = 0.058). Oxygen uptake during treadmill running tended to be higher (4.3%) in the Post-race placebo vs. No-race placebo (P = 0.074). Oxygen uptake was 5.4% lower in the Post-race menthol compared to the Post-race placebo (P = 0.018). Minute ventilation during treadmill running was 6.7–7.6% higher in the Post-race placebo compared to No-race placebo, whereas it was 6.6–9.0% lower in the Post-race menthol vs. Post-race placebo (all P ≤ 0.001). The rate of perceived exertion was 7.0% lower in the Post-race menthol vs. Post-race placebo (P = 0.007). Conclusions: Middle- and long-distance races can subsequently elevate muscle soreness and induce respiratory and metabolic stress, but post-race menthol application to the lower legs can mitigate these responses and reduce exercise exertion in long-distance runners. [ABSTRACT FROM AUTHOR]

Purpose: Leg muscle activation profiles and muscle-tendon interaction were studied with eleven internationally high-level Kenyan and eleven national level Japanese distance runners. Methods: Ultrasonography and kinematics were applied together with surface electromyography (EMG) recordings of leg muscles when subjects ran on treadmill at 9.0 (SLOW) and 13.9 km h (MEDIUM). Results: At each speed, both groups presented similar contact and flight times. The kinematic and ultrasound analyses revealed that, in contrast to the Japanese runners, the Kenyans demonstrated during contact smaller stretching and shortening amplitudes ( p < 0.01) of the tendinous tissue of medial gastrocnemius (MG), but greater tendon contribution to the muscle-tendon unit shortening ( p < 0.05). The MG fascicles of the Kenyans were shorter not only at the resting standing position, but also during the contact phase at both running speeds ( p < 0.01). The EMG profiles of the Kenyans showed lower braking/preactivation ratio in both MG and tibialis anterior ( p < 0.05) muscles. They were also characterized by negative relationships between the Achilles tendon moment arm and the MG fascicle shortening during contact ( r = −0.54, p < 0.01). In contrast, the Japanese presented the classical stretch-shortening cycle muscle activation profile of relatively high MG EMG activity during the braking phase. Conclusion: These findings provide new suggestions that the Kenyans have unique structural characteristics which can result in the reduction of muscle and tendinous stretch-shortening loading together with smaller muscle activation during contact at submaximal running speed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare sweating function in sprinters who have trained for several years with untrained subjects and trained endurance runners. Two separate experiments were conducted. Nine sprinters, eight untrained men, and nine distance runners ( $$\dot{V}{\text{o}}_{{ 2 {\text{max}}}}$$ 50.9 ± 1.4, 38.2 ± 1.8, and 59.1 ± 1.2 mL/kg/min, respectively; P < 0.05) were passively heated for 50 min (Experiment 1), and ten sprinters, 11 untrained men and nine distance runners (similar $$\dot{V}{\text{o}}_{{ 2 {\text{max}}}}$$ levels compared with Experiment 1 in each group) had their sweat gland capacity assessed based on acetylcholine-induced sweating rate (SR) (Experiment 2). The slope of the mean non-glabrous SR plotted against change in mean body temperature during passive heating did not differ significantly between sprinters and untrained men (1.21 ± 0.10 and 0.97 ± 0.12 mg cm/min/°C, respectively); in contrast, compared with untrained men, distance runners exhibited a significantly greater slope (1.42 ± 0.11 mg cm/min/°C, P < 0.05). The mean body temperature threshold for SR was not significantly different among the groups. Acetylcholine-induced SR did not differ significantly between sprinters and untrained men, whereas distance runners showed a significantly higher induced SR compared with untrained men. The sweating function was not improved in sprinters who have trained 2-3 h/day, 5 days/week, for at least 3 years compared with untrained men, although the $$\dot{V}{\text{o}}_{{ 2 {\text{max}}}}$$ was markedly greater in sprinters. Thus, there is a case that daily training was not sufficient to improve sweating function in sprinters relative to those in distance runners. [ABSTRACT FROM AUTHOR]

Here, we test the hypothesis that continuous concentric exercise training renders skeletal muscles more susceptible to damage in response to eccentric exercise. Elite road cyclists (CYC; n = 10, training experience 8.1 ± 2.0 years, age 22.9 ± 3.7 years), long-distance runners (LDR; n = 10, 9.9 ± 2.3 years, 24.4 ± 2.5 years), and healthy untrained (UT) men ( n = 10; 22.4 ± 1.7 years) performed 100 submaximal eccentric contractions at constant angular velocity of 60° s. Concentric isokinetic peak torque, isometric maximal voluntary contraction (MVC), and electrically induced knee extension torque were measured at baseline and immediately and 48 h after an eccentric exercise bout. Muscle soreness was assessed and plasma creatine kinase (CK) activity was measured at baseline and 48 h after exercise. Voluntary and electrically stimulated knee extension torque reduction were significantly greater ( p < 0.05) in UT than in LDR and CYC. Immediately and 48 h after exercise, MVC decreased by 32 % and 20 % in UT, 20 % and 5 % in LDR, and 25 % and 6 % in CYC. Electrically induced 20 Hz torque decreased at the same times by 61 and 29 % in UT, 40 and 17 % in LDR, and 26 and 14 % in CYC. Muscle soreness and plasma CK activity 48 h after exercise did not differ significantly between athletes and UT subjects. In conclusion, even though elite endurance athletes are more resistant to eccentric exercise-induced muscle damage than are UT people, stretch-shortening exercise-trained LDR have no advantage over concentrically trained CYC. [ABSTRACT FROM AUTHOR]

The purpose of the study was to characterize the changes in purine metabolism in long-distance runners in the main phases of their 1-year training cycle. Nine male athletes competing in distances 5 and 10 km at national/regional level, mean age 22.9 +/- 0.6 years, practising sport for 8.6 +/- 0.3 years, participated in the study. The changes in plasma concentrations of hypoxanthine (Hx), xanthine (X) and uric acid (UA) and the activity of the enzyme HGPRT in red blood cells haemolysate were followed in four characteristic points of the annual training cycle: preparatory phase (specific subphase), competition period, transition period and preparatory phase (intermediate subphase). Resting and postexercise plasma concentrations of X and, Hx and HGPRT activity changed significantly during 1-year training cycle. Significant changes in postexercise Hx values between training phases were found, from 9.3 micromol l(-1) in competition period to 22.9 micromol l(-1) in transition period (Friedmann's ANOVA, P < 0.01). Postexercise UA values ranged from 371 to 399 micromol l(-1) and did not change significantly between training phases. An increase in resting (from 52.0 to 58.4 IMP mg(-1) Hb min(-1), P < 0.05) and postexercise (from 70.7 to 76.2 IMP mg(-1) Hb min(-1), not significant) HGPRT activity between the specific preparation and competition period was observed. In the transition period, Hx postexercise concentration increased (22.9 micromol l(-1), P < 0.01) and HGPRT postexercise activity decreased (58.8 IMP mg(-1) Hb min(-1), P < 0.01) significantly. The results indicate that the level of plasma Hx at rest and after standard exercise may be a useful tool for monitoring the adaptation of energetic processes in different training phases and support the overload/overtraining diagnosis. [ABSTRACT FROM AUTHOR]