Beat Knechtle
University of Zurich
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Publication
Featured researches published by Beat Knechtle.
Journal of Sport & Exercise Psychology | 2014
Julia Schüler; Mirko Wegner; Beat Knechtle
Previous research has shown that the effects of basic psychological needs on the flow experience in sports are moderated by implicit motives. However, so far, only leisure and health-oriented sports have been analyzed. In a pilot study and a main study (N = 29, 93), we tested whether the implicit achievement and affiliation motives interact with the need for competence and the need for social relatedness satisfaction, respectively, to predict flow experience and well-being in extreme endurance athletes. Results showed that highly achievement-motivated individuals benefited more from the need for competence satisfaction in terms of flow than individuals with a low achievement motive did. In addition, highly affiliation-motivated individuals whose need for social relatedness is satisfied reported higher positive affect and lower exercise addiction scores than athletes with a low motive. We discuss the differential effects of the interplay between the achievement and affiliation motives and basic needs on different outcome variables.
Research in Sports Medicine | 2018
Pantelis T. Nikolaidis; Beat Knechtle
ABSTRACT The aim of the study was to investigate how women and men age group runners pace during a large city marathon. We analysed changes in running speed by splits of 5 km in 20,283 women and 28,282 men age group runners competing in the 2015 edition of the “New York City Marathon”. A moderate split×sex interaction on running speed (p < 0.001, η2 = 0.108) was observed with men showing a larger decrease in speed from the fastest split (5–10 km) to the slowest one (35–40 km) than women (21.1 vs. 16.7%), and a different pattern was observed in the 25–30 km split (increase in women, decrease in men). A trivial split×age group interaction on speed was observed in women (p < 0.001, η2 = 0.003) and men (p < 0.001, η2 = 0.004). In summary, men and women of all age groups reduced running speed during the marathon with a final spurt in the last segment (i.e. 40–42.2 km).
Open access journal of sports medicine | 2018
Pantelis T. Nikolaidis; Beat Knechtle
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.
Journal of Sports Sciences | 2018
Alessandro Moura Zagatto; Miran Kondrič; Beat Knechtle; Pantelis Nikolaidis; Billy Sperlich
ABSTRACT Table tennis is a racket sport characterised by an intermittent movement profile, including short rallies interspersed with short breaks. In contrast to other racket sports, information is lacking regarding the: (i) physiological responses during table tennis matches and training; and (ii) practical recommendations for enhancing aerobic and anaerobic performance in table tennis by improving cardio-metabolic and neuro-muscular fitness, anthropometry and nutritional strategies. Therefore, this review article attempts to narratively provide an overview of the physiology of table tennis by describing the metabolic mechanisms underlying match play and outlining a framework for practical recommendations for improving cardio-metabolic and neuro-muscular fitness, anthropometry as well as nutritional strategies. A second aim was to stimulate future research on table tennis and to point out study limitations in this context. In general, the most important finding is that the rally duration is short at around 3.5s, with a longer rest time of around 8–20s, resulting in an effort-rest ratio ranging from 0.15 to 0.22 in official matches and energetic demands during match relatively low. Future studies should focus on the relationship between energetic demand and table tennis performance with a view to predicting performance in table tennis using physiological parameters.
Journal of Sports Sciences | 2018
Pantelis T. Nikolaidis; Beat Knechtle
ABSTRACT Demographic and performance data from 197,825 athletes competing in “Engadin Ski Marathon” between 1998 and 2016 were analysed. When all finishers per age group were considered, there was no gender difference in time (2:59:00 in women versus 2:59:09 h:min:s in men; P = 0.914, η2 < 0.001) and the main effect of age group on time was trivial (P < 0.001, η2 = 0.007). When the top 10 finishers per age group were considered, men were faster than women (1:27:32 versus 1:34:19 h:min:s, respectively; P < 0.001, η2 = 0.373), there was a large effect of age group on time (P < 0.001, η2 = 0.590) and the gender difference was larger in the older than in the younger age groups (P < 0.001, η2 = 0.534). The age of peak performance for all finishers by 1-year interval age group was 40.3 and 39.6 years in all women and men, respectively. The top 10 finishers by 1-year interval age group achieved their peak performance in the age of 38.4 and 42.2 years in women and men, respectively. The age of peak performance was older and the age-related performance decline occurred earlier in marathon cross-country skiing, compared to road-based marathon running.
Frontiers in Physiology | 2018
Beat Knechtle; Pantelis T. Nikolaidis
In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra-marathons, ~50–60% of the participants experience musculoskeletal problems. The most common injuries in ultra-marathoners involve the lower limb, such as the ankle and the knee. An ultra-marathon can lead to an increase in creatine-kinase to values of 100,000–200,000 U/l depending upon the fitness level of the athlete and the length of the race. Furthermore, an ultra-marathon can lead to changes in the heart as shown by changes in cardiac biomarkers, electro- and echocardiography. Ultra-marathoners often suffer from digestive problems and gastrointestinal bleeding after an ultra-marathon is not uncommon. Liver enzymes can also considerably increase during an ultra-marathon. An ultra-marathon often leads to a temporary reduction in renal function. Ultra-marathoners often suffer from upper respiratory infections after an ultra-marathon. Considering the increased number of participants in ultra-marathons, the findings of the present review would have practical applications for a large number of sports scientists and sports medicine practitioners working in this field.
Research in Sports Medicine | 2018
Beat Knechtle; Pantelis Nikolaidis
ABSTRACT In road runners, the age-related performance decline has been well investigated for marathoners, but little is known for half-marathoners. We analysed data from 138,616 runners (48,148 women and 90,469 men) competing between 2014 and 2016 in GöteborgsVarvet, the world’s largest half-marathon. The men-to-women ratio in participants increased with age, the fastest race times were observed in age groups ˂35 and 35–39 years in women and in age group 35–39 years in men, the main effect of sex and the sex × age group interaction on race time were trivial, and the competitiveness was denser in men and in the younger age groups. In summary, in half-marathon running in the largest half-marathon in the world, the GöteborgsVarvet, women achieved the fastest race time at an earlier age compared to men where the fastest race times were observed in women in age groups ˂35 and 35–39 years and in men in age group 35–39 years.
Research in Sports Medicine | 2018
Pantelis T. Nikolaidis; Caio Victor Sousa; Beat Knechtle
ABSTRACT In open-water swimming events with non-elite swimmers held in the USA, but not in Europe, women were faster than men. We examined the sex difference in elite long-distance open-water swimming races and the role of nationality by investigating 7,468 swimmers competing in 5 km, 10 km and 25 km FINA races held between 2000 and 2016. More men participated in 10 km and 25 km than in 5km races. Men were faster than women and the sex difference was similar in all race distances. Swimming speed was faster for 5km than for 10km, which in turn was faster than 25km. There was a major effect of nationality on swimming speed at 5 km and 10 km, but not at 25km. No dominance of a particular nationality was observed for all race distances. In summary, men were faster than women in all FINA race distances from 5km to 25km but nationality played no role in the sex difference.
Frontiers in Physiology | 2018
Pantelis T. Nikolaidis; Filipe Manuel Clemente; Cornelis M. I. (Niels) van der Linden; Thomas Rosemann; Beat Knechtle
The objectives of the present study were to examine the validity and reliability of the 10 Hz Johan GPS unit in assessing in-line movement and change of direction. The validity was tested against the criterion measure of 200 m track-and-field (track-and-field athletes, n = 8) and 20 m shuttle run endurance test (female soccer players, n = 20). Intra-unit and inter-unit reliability was tested by intra-class correlation coefficient (ICC) and coefficient of variation (CV), respectively. An analysis of variance examined differences between the GPS measurement and five laps of 200 m at 15 km/h, and t-test examined differences between the GPS measurement and 20 m shuttle run endurance test. The difference between the GPS measurement and 200 m distance ranged from −0.13 ± 3.94 m (95% CI −3.42; 3.17) in the first lap to 2.13 ± 2.64 m (95% CI −0.08; 4.33) in the fifth lap. A good intra-unit reliability was observed in 200 m (ICC = 0.833, 95% CI 0.535; 0.962). Inter-unit CV ranged from 1.31% (fifth lap) to 2.20% (third lap). The difference between the GPS measurement and 20 m shuttle run endurance test ranged from 0.33 ± 4.16 m (95% CI −10.01; 10.68) in 11.5 km/h to 9.00 ± 5.30 m (95% CI 6.44; 11.56) in 8.0 km/h. A moderate intra-unit reliability was shown in the second and third stage of the 20 m shuttle run endurance test (ICC = 0.718, 95% CI 0.222;0.898) and good reliability in the fifth, sixth, seventh and eighth (ICC = 0.831, 95% CI −0.229;0.996). Inter-unit CV ranged from 2.08% (11.5 km/h) to 3.92% (8.5 km/h). Based on these findings, it was concluded that the 10 Hz Johan system offers an affordable valid and reliable tool for coaches and fitness trainers to monitor training and performance.
PLOS ONE | 2018
Beat Knechtle; Pantelis T. Nikolaidis; Fabio Valeri
Objectives A recent study investigating the top 10 100-km ultra-marathoners by nationality showed that Japanese runners were the fastest worldwide. This selection to top athletes may lead to a selection bias and the aim of this study was to investigate from where the fastest 100-km ultra-marathoners originate by considering all finishers in 100-km ultra-marathons since 1959. Methods We analysed data from 150,710 athletes who finished a 100-km ultra-marathon between 1959 and 2016. To get precise estimates and stable density plots we selected only those nationalities with 900 and more finishes resulting in 24 nationalities. Histograms and density plots were performed to study the distribution of race time. Crude mean, standard deviation, median, interquartile range (IQR), mode, skewness and excess of time for each nationality were computed. A linear regression analysis adjusted by sex, age and year was performed to study the race time between the nationalities. Histograms, density and scatter plots showed that some races seemed to have a time limit of 14 hours. From the complete dataset the finishes with more than 14 hours were removed (truncated dataset) and the same descriptive plots and analysis as for the complete dataset were performed again. In addition to the linear regression a truncated regression was performed with the truncated dataset to allow conclusion for the whole sample. To study a potential difference between races at home and races abroad, an interaction term race site home/abroad with nationality was included in the model. Results Most of the finishes were achieved by runners from Japan, Germany, Switzerland, France, Italy and USA with more than 260’000 (85%) finishes. Runners from Russia and Hungary were the fastest and runners from Hong Kong and China were the slowest finishers. Conclusion In contrast to existing findings investigating the top 10 by nationality, this analysis showed that ultra-marathoners from Russia, not Japan, were the fastest 100-km ultra-marathoners worldwide when considering all races held since 1959.