Age of peak performance in 50-km ultramarathoners - is it older than in marathoners?

Purpose: Despite the increasing popularity of 50-km ultramarathons during the last few years, only limited information is available regarding the trends in its performance and participation. The aim of the present study was to examine the age of peak running performance in female and male 50-km ultramarathoners using second-order nonlinear regression analyses. Methods: Data from 494,414 runners (124,045 women and 370,369 men) who finished a 50-km ultramarathon between 1975 to 2016 were analyzed. Results: When the top ten finishers in 1-year age-groups were analyzed, the age of peak running speed was 41 years in both women and men. When the fastest finishers in 1-year age-group intervals were analyzed, the age of peak running speed was 40 years in women and 39 years in men. Conclusion: In summary, the age of peak running speed in 50-km ultramarathoners is older than what has been reported by previous studies for marathons. Women seem to achieve the best race time in a 50-km ultramarathon later in life compared with men. These findings are of great practical value for coaches and fitness trainers when setting performance goals for 50-km ultramarathon runners

Differences in Force-velocity Characteristics of Upper and Lower Limbs of Non-competitive Male Boxers

Int J Exerc Sci 5(2) : 106-113, 2012. Despite the increasing popularity of boxing, only a few studies have been conducted on the physiology or the biomechanics of this sport. The aim of the present study is to examine the ratios of mechanical characteristics (maximal anaerobic power, Pmax, theoretical maximal force, F0, and velocity, v0) between upper and lower limbs of male boxers. Twelve male caucasians, all members of a local fitness club, aged 29.5 (3.2) yr [mean (standard deviation)], stature 1.74 (.05) m, body mass 77.9 (8.1) kg, body fat 22.4 (3.9) % and somatotype 5.5-5.5-1.1, performed a force-velocity (F-v) test for both legs and arms. The F-v test included five supramaximal pedal sprints, each lasting 7 sec, against incremental braking force of 20-60 N for arms and 30-70 N for legs, on modified arm-cranking and on cycle ergometer (Ergomedics 874, Monark, Sweden). The legs had higher Pmax (910 W vs. 445 W, t11=22.9, p\u3c.001), Pmax expressed in relative to body mass values (rPmax, 11.8 W.kg-1 vs. 5.8 W.kg-1, t11=20.6,p\u3c.001), F0 (168 N vs. 102 N, t11=21.7, p\u3c.001), v0 (217 rpm vs. 177 rpm, t11=46.6, p\u3c.001) and lower v0/F0 (1.33 rpm.N-1 vs. 1.82 rpm.N-1, t11=15.3, p\u3c.001) than the arms. Pmax of upper limbs was associated with Pmax of lower limbs (r=.70, p\u3c.05) and their ratio was .49 (.06). The respective values of rPmax was r=.76 (p\u3c.01), F0, r=.35 (p=.26) and .61 (.13), and of velocity, v0,r=.17 (p=.59) and .812 (.10). In spite of moderate associations between upper and lower limbs’ F0 and v0, a stronger relationship was found with regard to Pmax. These findings emphasize the need for separate evaluation of arms’ and legs’ F-v characteristics on a regular basis and the consideration of these measures in training design

Force-Velocity Characteristics, Muscle Strength, and Flexibility in Female Recreational Marathon Runners

Physical fitness components that relate with performance in marathon running, e.g., aerobic capacity and body composition, have been studied extensively. On the other hand, data on components of the health-related physical fitness, such as flexibility and muscle strength, were missing in this sport. Therefore, the aim of the present study was to profile force-velocity (F-v) characteristics, muscle strength and flexibility in female recreational marathon runners and to examine their relationship with age, race time and anthropometric characteristics (body fat percentage, fat-free mass – FFM, and total thigh muscle cross-sectional area – CSA). Thirty three female marathon runners (age 40.0 ± 8.9 years, body fat percentage 19.5 ± 4.6% and personal record 4:34 ± 0:39 h:min), separated into three age groups (<35, 35–45 and >45 years) and three performance groups (race time <4:15 h:min, 4:15–4:45 h:min and >4:45 h:min), performed sit-and-reach test (SAR), isometric muscle strength tests, squat jump, countermovement jump and F-v test on a cycle ergometer. The main findings of the present study were that (i) participants had moderate scores of body composition and physical fitness considering norms of the general population, (ii) the <35 age group had better jumping ability than 35–45 and >45 age group, and the older age group had lower F0, Pmax and rPmax than their younger counterparts, (iii) the slowest performance group scored the highest in SAR, and (iv) isometric strength, F0 and Pmax correlated largely with body mass and FFM. Considering the lack of existing data on anaerobic power and neuromuscular fitness of female marathon runners, the findings reported in this study would be useful for strength and conditioning trainers to monitor the training of their athletes. Even if these parameters were not related to race time, they should be monitored regularly as they were either component of health-related physical fitness (muscle strength and flexibility) or could help runners (anaerobic power) under specific circumstances such as ascends during a race

Skinfold thickness variation and associations with cardiorespiratory fitness in male soccer players of different ages

OBJECTIVE: The aim of the present study was to examine skinfold thickness (SKF) distribution in youth and adult male soccer players regarding cardiorespiratory fitness (CRF) and the role of age. PATIENTS AND METHODS: Participants were youth [n=83, age 16.2 (1.0) years, mean (standard deviation)] and adult male soccer players [n=121, 23.2 (4.3) years], who were tested for SKF on 10 anatomical sites and Conconi test was used to assess velocity at maximal oxygen uptake (vVO2max). RESULTS: A between-within-subjects analysis of variance revealed a small interaction between the anatomical site and age group on SKF (p=0.006, η2=0.022), where adolescents had larger cheek (+0.7 mm; p=0.022; 95% confidence intervals - CI  - 0.1, 1.3), triceps (+0.9 mm; p=0.017; 95% CI 0.2, 1.6) and calf (+0.9 mm; p=0.014; 95% CI 0.2, 1.5) SKF, while adults had larger chin (+0.5 mm; p=0.007; 95% CI 0.1, 0.8) SKF, and no difference was observed for the rest of the anatomical sites. No difference between adolescent and adult age groups was observed in average SKF (SKFavg) [9.0 (2.7) vs. 9.1 (2.5) mm; difference -0.1 mm; 95% CI, -0.8, 0.6; p=0.738]. Compared to adults, adolescents had a lower SKF coefficient of variation (SKFcv) [0.34 (0.10) vs. 0.37 (0.09); difference-0.03; 95% CI, -0.06, -0.01; p=0.020] and subscapular-to-triceps ration (STR) [1.08 (0.28) vs. 1.29 (0.37); difference-0.21; 95% CI, -0.31, -0.12; p<0.001]. The largest Pearson moment correlation coefficient between vVO2max and SKF was shown in the subscapular (r=-0.411; 95% CI, -0.537, -0.284; p<0.001) and the smallest in the patellar anatomical site (r=-0.221; 95% CI, -0.356, -0.085; p=0.002). In addition, vVO2max correlated moderately with SKFavg (r=-0.390; 95% CI, -0.517, -0.262; p<0.001) and SKFcv (r=-0.334; 95% CI, -0.464, -0.203; p<0.001). CONCLUSIONS: In summary, CRF was related to the thickness of specific SKF and the magnitude of thickness variation by the anatomical site (i.e., the smaller the variation, the better the CRF). Considering the relevance of specific SKF for CRF, their further use would be recommended for monitoring physical fitness in soccer players

Swimming three ice miles within fifteen hours

Ice Mile swimming (1608 m in water of below 5 °Celsius) is becoming increasingly popular. This case study aimed to identify body core temperature and selected haematological and biochemical parameters before and after repeated Ice Miles. An experienced ice swimmer completed three consecutive Ice Miles within 15 h. Swim times, body core temperatures, and selected urinary and haematological parameters were recorded. Body core temperature reached its maximum between 5, 8 and 15 min after immersion (37.7°C, 38.1°C, and 38.0°C, respectively). The swimmer suffered hypothermia during the first Ice Mile (35.4°C) and body core temperature dropped furthermore to 34.5°C during recovery after the first Ice Mile. He developed a metabolic acidosis in both the first and the last Ice Mile (pH 7.31 and pH 7.34, respectively). We observed hyperkalaemia ([K⁺] > 5.5 mM) after the second Ice Mile (6.9 mM). This was followed by a drop in [K⁺] to3.7 mM after the third Ice Mile. Anticipatory thermogenesis (i.e. an initial increase of body core temperature after immersion in ice cold water) seems to be a physiological response in a trained athlete. The results suggest that swimming in ice-cold water leads to a metabolic acidosis, which the swimmer compensates with hyperventilation (i.e. leading to respiratory alkalosis). The shift of serum [K⁺] could increase the risk of a cardiac arrhythmia. Further studies addressing the physiology and potential risks of Ice Mile swimming are required to substantiate this finding

Is there stability in the performance of elite half-marathoners?

The purpose of this study was to investigate the performance stability of elite half-marathoners of both sexes. The study was composed of 24 elite athletes (12 female and 12 male), ranked among the Senior World TOP20 half-marathoners, who completed a half-marathon race for at least three consecutive years. Tracking was tested using autocorrelations and Kappa Cohen. Autocorrelation revealed a significant association, but a decrease in correlation among the years in both sexes. The overall weighted kappa showed lower stability in performance for both sexes (K ​= ​0.191 and K ​= ​-0.245) than for males. These findings suggest that both female and male elite half-marathoners showed low stability in performance during three events. Besides that, athletes with a better performance tended to present the highest performance stability. It is recommended that coaches track the developmental trajectories of the athletes to comprised the changes in performance across the years, as to provide environmental characteristics that can influence performance. Keywords: Elite athletes; Endurance; Running; Trackin

Association between physical activity patterns and anthropometric characteristics of adults : an issue of public health?

The aim of this study was to evaluate the association between objectively measured daily physical activity (PA) and body fat mass (BF) and body mass index (BMI). A further aim was to analyse the variance of PA between quartiles of BF and BMI. Material and methods: A cross-sectional, observational study of 126 university students (53 males aged 20.46 ± 2.04 years and 73 female aged 19.69 ± 1.32 years) was conducted. Results: The female participants and PA characteristics explain 57.10% of BF variance and the model was statistically significant (F(6, 875) = 196.38; p = 0.001). BMI was also included in the model. Standard binary logistic regression was used to test the hypothesis that female sex and PA characteristics can influence overweight. The full model containing all variables was statistically significant (G2(6) = 58.598, p-value = 0.001). Analysis of variance between BF quartiles revealed statistically significant differences in male participants in light PA (p = 0.001; ES = 0.09), moderate PA (p = 0.001; ES = 0.042) and vigorous PA (p = 0.001; ES = 0.130). Conclusions: The statistical model in the regression analysis suggests that low and vigorous levels of PA explain 57% of BF variance in female participants.info:eu-repo/semantics/publishedVersio

Weekly physical activity patterns of university students : are athletes more active than non‑athletes?

The aim of the present study was to compare weekly physical activity (PA) and obesity-related markers in athlete and non-athlete university students. One hundred and twenty-six university students (53 males, 20.46 ± 2.04 years old, and 73 females, 19.69 ± 1.32 years old) participated in this study. Participants were fitted with a tri-axial accelerometer (ActiGraph wGT3X-BT, Shalimar, FL, USA) to assess the daily PA. Anthropometric measures of height, weight, BMI and %fat mass were determined with a stadiometer and an electronic scale. The comparison indicated that male and female athletes had a significant lower percentage of body fat than did non-athletes (p value = 0.001; ES = 0.043). Athletes spent significantly more time in light PA than did non-athletes (p value = 0.003; ES = 0.024). Female athletes spent significantly less time in sedentary mode than did non-athletes (p value = 0.040; ES = 0.008). On the other hand, female athletes spent significantly more time in light PA (p value = 0.003; ES = 0.017) and vigorous PA (p value = 0.001; ES = 0.086) than did non-athletes. Despite some statistical differences with minimal effect size, the results of this study suggested proximity between PA levels of athletes and non-athletes, mainly in the case of sedentary behaviour. No significant effects were found in the variances of PA tested in this study.info:eu-repo/semantics/publishedVersio