The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race

Pacing Behaviour Development and Acquisition: A Systematic Review

BACKGROUND

The goal-directed decision-making process of effort distribution (i.e. pacing) allows individuals to efficiently use energy resources as well as to manage the impact of fatigue on performance during exercise. Given the shared characteristics between pacing behaviour and other skilled behaviour, it was hypothesized that pacing behaviour would adhere to the same processes associated with skill acquisition and development.

METHODS

PubMed, Web of Science and PsycINFO databases between January 1995 and January 2022 were searched for articles relating to the pacing behaviour of individuals (1) younger than 18 years of age, or (2) repeatedly performing the same exercise task, or (3) with different levels of experience.

RESULTS

The search resulted in 64 articles reporting on the effect of age (n = 33), repeated task exposure (n = 29) or differing levels of experience (n = 13) on pacing behaviour. Empirical evidence identifies the development of pacing behaviour starts during childhood (~ 10 years old) and continues throughout adolescence. This development is characterized by an increasingly better fit to the task demands, encompassing the task characteristics (e.g. duration) and environment factors (e.g. opponents). Gaining task experience leads to an increased capability to attain a predetermined pace and results in pacing behaviour that better fits task demands.

CONCLUSIONS

Similar to skilled behaviour, physical maturation and cognitive development likely drive the development of pacing behaviour. Pacing behaviour follows established processes of skill acquisition, as repeated task execution improves the match between stimuli (e.g. task demands and afferent signals) and actions (i.e. continuing, increasing or decreasing the exerted effort) with the resulting exercise task performance. Furthermore, with increased task experience attentional capacity is freed for secondary tasks (e.g. incorporating opponents) and the goal selection is changed from achieving task completion to optimizing task performance. As the development and acquisition of pacing resemble that of other skills, established concepts in the literature (e.g. intervention-induced variability and augmented feedback) could enrich pacing research and be the basis for practical applications in physical education, healthcare, and sports.

The Biology of Sex and Sport

Sex and gender are not the same. Sex is defined by the human genotype and pertains to biologic differences between males and females. Gender is a fluid concept molded by self-perception, social constructs, and culturally laden attitudes and expectations of men and women. In general, males have longer limb levers, stronger bones, greater muscle mass and strength, and greater aerobic capacity. Females exhibit less muscle fatigability and faster recovery during endurance exercise. Physiologic sex-based differences have led to an average performance gap of 10% that has remained stable since the 1980s. The performance disparity is lowest for swimming and highest for track and field events. The International Olympic Committee currently mandates that female athletes with differences of sex development, or intersex traits, and transgender female athletes must limit their blood testosterone to <10 nmol/L for 12 months to be eligible for competition in the female classification.

Determinants of the Cardiovascular Capacity of Amateur Long-Distance Skiers during the Transition Period

The aim of this study was to identify determinants of the cardiovascular capacity of 16 male amateur long-distance skiers during the transition period. These factors can vary from amateur marathon skiers, who represent a sort of midpoint between inactive people and professional athletes. Cardiovascular capacity depends mainly on the volume and intensity of the training, which are different between these groups. Finding the factors affecting heart condition of amateur athletes can be an important element in their health care and can help the athletes to achieve their full performance potential. Therefore, ergospirometric and hematological tests were performed. As a result, predictors for volume oxygen uptake were determined using a regression model, which included the following variables: the percentage of monocytes (p = 0.031), the concentration of sodium (p = 0.004), and total calcium (p = 0.03). All these parameters negatively affected VO2 max. Biochemical and physiological monitoring of amateur athletes can help to protect their health and prepare them properly for their training. The growing popularity of long-distance competitions among middle-aged amateur athletes and the lack of guidance on how to assess their health indicate the need for further research.

Cardiovascular Adaptations to Four Months Training in Middle-Aged Amateur Long-Distance Skiers

Cross-country skiing has a positive effect on health. However, without an individual, thoughtful, and professional plan, it can cause irreversible health problems from overload and injury. The impact of exercise on results is well understood within the group of professional athletes. However, this remains unknown within the group of amateur cross-country skiers and marathon runners—in particular, the impact of the summer preparation period in which training loads performed in the oxygen zone combined with resistance training dominate. The aim of this study was to assess changes in the cardiovascular capacity and body mass composition of male cross-country skiers in the preparation period of their macrocycle. Variables were analyzed using basic descriptive statistics: mean and standard deviation (SD). To compare the results from both measurements (initial and final) the paired Wilcoxon test was used. A statistically significant increase was noted in maximum oxygen uptake and maximum minute ventilation, and a decrease in body fat content, maximum lactate concentration and lactate threshold, and heart rate on anaerobic threshold. Research indicated that in the amateur group increases similar to those in top competitors were achieved in the parameters tested, but the initial level was often significantly lower.

Biomechanical determinants of cross-country skiing performance: A systematic review

Cross-country skiing is a complex endurance sport requiring technical skills, in addition to considerable physiological and tactical abilities. This review aims to identify biomechanical factors that influence the performance of cross-country skiers. Four electronic databases were searched systematically for original articles in peer-reviewed journals addressing the relationship between biomechanical factors (including kinematics, kinetics, and muscle activation) and performance while skiing on snow or roller skiing. Of the 46 articles included, 22 focused exclusively on the classical technique, 18 on the skating technique, and six on both. The indicators of performance were: results from actual or simulated races (9 articles); speed on specific tracts (6 articles); maximal or peak speed (11 articles); skiing economy or efficiency (11 articles); and grouping on the basis of performance or level of skill (12 articles). The main findings were that i) cycle length, most often considered as a major determinant of skiing speed, is also related to skiing economy and level of performance; ii) higher cycle rate related with maximal speed capacity, while self-selected cycle rate improves skiing economy at sub-maximal speeds; iii) cross-country skiing performance appears to be improved by joint, whole-body, ski, and pole kinematics that promote forward propulsion while minimizing unnecessary movement.

Double poling kinematic changes during the course of a long-distance race: effect of performance level

We aimed to evaluate the changes in double poling (DP) kinematics due to a long-distance cross-country skiing race in athletes with different performance levels. A total of 100 cross-country skiers, belonging to 10 different performance groups, were filmed on flat terrain 7 and 55 km after the start line, during a 58-km classical race. Cycle velocity, frequency and length decreased from the best to the lower-ranked group, while duty cycle increased (all P <.001). Between track sections, cycle velocity and length decreased, duty cycles increased (all P <.001) while frequency was unaltered (P =.782). Group*section interactions resulted for cycle velocity (P =.005). Considering all the participants together, % change in cycle velocity between sections correlated with % change in length and duty cycle (all P <.001). Thus i) skiers in better groups showed longer and more frequent cycles as well as shorter duty cycles than skiers in slower groups; ii) throughout the race all the groups maintained the same cycle frequency while decreasing cycle velocity and length; iii) better groups showed a lower reduction in cycle velocity. Individually, a low reduction in cycle velocity during the race related to the capacity to maintain long cycles and short duty cycles.

Pacing, Exercise Intensity, and Technique by Performance Level in Long-Distance Cross-Country Skiing

Introduction

Long-distance cross-country skiing (XCS) has gained increased popularity within the past decades. However, research about long-distance XCS is limited; therefore, the aim of this study was to analyze the intensity distribution, technique application, and pacing strategies during long-distance XCS racing.

Methods

Heart rate (HR) and section skiing speeds of 9 elite (ranked 1–100) and 10 amateur skiers (ranked 101–1,500) during the 90-km Vasaloppet race were collected. In addition, during the first uphill, the first 1,000 skiers were video-recorded to analyze the applied skiing strategy (e.g. grip-waxed skis versus exclusive double poling).

Results

Mean race intensity was 82% of maximal HR and was not different between performance groups even though elite skiers skied ∼15% faster than amateurs. There was an interaction effect of section × group with a pronounced decrease in HR in amateurs compared with more even pacing in elite skiers (0.13 vs. 0.04% decrease/km) and skiing at higher percentage in the high-intensity zones in elite compared with amateurs (46 vs. 24%). Ninety-eight percent of the top 100 skiers and 59% of the first 1,000 skiers used exclusively double poling.

Conclusion

Elite and amateur skiers ski at comparable mean race exercise intensity, but they have clear differences in skiing speed. The difference in the pacing profiles between elite and amateur skiers (more even vs. distinct positive pacing) demonstrate the greater capacity of the former with respect to physiological capacity and highlights that amateurs seem to start too fast according to their capacities. The exclusive application of the double poling technique is no longer a phenomenon of elite skiers but is widely used among the top 1,000 ranked skiers.

Long distance ski racing is associated with lower long-term incidence of depression in a population based, large-scale study

Physical activity has been proposed to be beneficial for prevention of depression, although the importance of exercise intensity, sex-specific mechanisms, and duration of the effects need to be clarified. Using an observational study design, following 395,369 individuals up to 21 years we studied whether participation in an ultralong-distance cross-country ski race was associated with lower risk of developing depression. Skiers (participants in the race) and matched non-skiers from the general population (non-participants in the race) were studied after participation (same year for non-participation) in the race using the Swedish population and patient registries. The risk of depression in skiers (n = 197,685, median age 36 years, 38% women) was significantly lower, to nearly half of that in non-skiers (adjusted hazard ratio, HR 0.53) over the follow-up period. Further, a higher fitness level (measured as the finishing time to complete the race, a proxy for higher exercise dose) was associated with lower incidence of depression in men (adjusted HR 0.65), but not in women. Our results support the recommendations of engaging in physical activity as a preventive strategy decreasing the risk for depression in both men and women. Furthermore, the exercise could reduce risk for depression in a dose-dependent matter, in particular in males.

The Differences in Pacing Among Age Groups of Amateur Cross-Country Skiers Depend on Performance

Pacing strategies have mainly been investigated for runners, but little is known for cross-country skiers. The aim of the present study was to examine the effects of performance and age on pacing strategies in cross-country skiing. All finishers (women, n = 19,375; men, n = 86,190) in the 'Engadin Ski Marathon' (42 km) between 1998 and 2016 were analysed for the percentage change of speed at 10 km (Change A), 20 km (Change B) and 35 km (Change C). They were classified in performance groups according to quartiles of average race speed (Q1, Q2, Q3 and Q4) and in 5-year age groups (<20, 20-24, 25-29… 85-89 years). Men were faster than women by +14.3% (15.2 ± 4.0 vs. 13.3 ± 3.3 km/h; p < 0.001, η² = 0.215). A small impact of age group × performance group interaction on Change A was shown in women (p < 0.001, η² = 0.026) and men (p < 0.001, η² = 0.025), where Q1 augmented and Q4 attenuated the decrease in speed with aging. However, the impact of age group × performance group interaction on Change B and C was trivial (p = 0.002, η² ≤ 0.010). Based on these findings, it was concluded that the differences in pacing among age groups depended on the performance level. Thus, the coaches and fitness trainers working with cross-country skiers should advise their athletes to consider both age and performance.

Performance and Participation in the 'Vasaloppet' Cross-Country Skiing Race during a Century

This study investigated gender differences in performance and participation and the role of nationality during one century in one of the largest cross-country (XC) skiing events in the world, the 'Vasaloppet' in Sweden. The total number of female and male athletes who finished (n = 562,413) this race between 1922 and 2017 was considered. Most of the finishers were Swedish (81.03% of women and 88.39% of men), followed by Norwegians and Finnish. The overall men-to-women ratio was 17.5. A gender × nationality association was observed for participation (χ2 = 1,823.44, p < 0.001, φ = 0.057), with the men-to-women ratio ranging from 6.7 (USA) to 19.1 (Sweden). For both genders, the participation (%) of Swedish decreased, and that of all other nationalities (except Swiss) increased across years. Regarding the mean race time, men were faster than women by 14.5% (7 h 52 min 17 s versus 9 h 00 min 55 s, respectively). A trivial gender×nationality interaction regarding the race time was observed (p < 0.001, η2 < 0.001), with gender differences ranging from 4.4% (USA) to 22.0% (Iceland). The race time increased across calendar years for both women (r = 0.45, p = 0.006, moderate magnitude) and men (r = 0.25, p = 0.015, small magnitude). On the basis of these findings, we concluded that a relatively small number of women pariticipates in XC skiing. Therefore, the development of public health policies targeting the participation of women in XC skiing should be a concern in the countries with a tradition of this sport.

Pacing Decision Making in Sport and the Effects of Interpersonal Competition: A Critical Review

An athlete's pacing strategy is widely recognised as an essential determinant for performance during individual events. Previous research focussed on the importance of internal bodily state feedback, revealed optimal pacing strategies in time-trial exercise, and explored concepts such as teleoanticipation and template formation. Recently, human-environment interactions have additionally been emphasized as a crucial determinant for pacing, yet how they affect pacing is not well understood. Therefore, this literature review focussed on exploring one of the most important human-environment interactions in sport competitions: the interaction among competitors. The existing literature regarding the regulation of exercise intensity and the effect of competition on pacing and performance is critically reviewed in this paper. The PubMed, CINAHL and Web of Science electronic databases were searched for studies about pacing in sports and (interpersonal) competition between January 2000 to October 2017, using the following combination of terms: (1) Sports AND (2) Pacing, resulting in 75 included papers. The behaviour of opponents was shown to be an essential determinant in the regulation of exercise intensity, based on both observational (N = 59) and experimental (N = 16) studies. However, adjustment in the pacing response related to other competitors appears to depend on the competitive situation and the current internal state of the athlete. The findings of this review emphasize the importance of what is happening around the athlete for the outcome of the decision-making process involved in pacing, and highlight the necessity to incorporate human-environment interactions into models that attempt to explain the regulation of exercise intensity in sports and exercise.

The effect of sex and performance level on pacing in cross-country skiers: Vasaloppet 2004-2017

BACKGROUND

Pacing, defined as percentage changes of speed between successive splits, has been extensively studied in running and cycling endurance sports; however, less information about the trends in change of speed during cross-country (XC) ski racing is available. Therefore, the aim of the present study was to examine the effect of performance (quartiles of race time (Q), with Q1 the fastest and Q4 the slowest) level on pacing in the Vasaloppet ski race, the largest XC skiing race in the world.

METHODS

For this purpose, we analyzed female (n = 19,465) and male (n = 164,454) finishers in the Vasaloppet ski race from 2004 to 2017 using a one-way (2 sexes) analysis of variance with repeated measures to examine percentage changes of speed between 2 successive splits. Overall, the race consisted of 8 splits.

RESULTS

The race speeds of Q1, Q2, Q3, and Q4 were 13.6 ± 1.8, 10.6 ± 0.5, 9.2 ± 0.3, and 8.1 ± 0.4 km/h, respectively, among females and 16.7 ± 1.7, 13.1 ± 0.7, 10.9 ± 0.6, and 8.9 ± 0.7 km/h, respectively, among males. The overall pacing strategy of finishers was variable. A small sex × split interaction on speed was observed (η ² = 0.016, p < 0.001), with speed difference between sexes ranging from 14.9% (Split 7) to 27.0% (Split 1) and larger changes in speed between 2 successive splits being shown for females (p < 0.001, η ² = 0.004). A large performance × split interaction on speed, with Q1 presenting the smallest changes of speed between splits, was shown for females (η ² = 0.149, p < 0.001) and males (η ² = 0.169, p < 0.001).

CONCLUSION

Male and fast XC skiers are more even pacers. Coaches and athletes should develop tailored sex- and performance-level pacing strategies; for instance, they should advise fast XC skiers to start fast and maintain their speed, rather than starting slowly and trying to make up time by going faster at times during the race.

Pacing and predictors of performance during cross-country skiing races: A systematic review

BACKGROUND

Cross-country skiing (XCS) racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS racers.

METHODS

Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peer-reviewed journals and the English language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were reviewed.

RESULTS

All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions (e.g., weather, ski properties) were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling, less diagonal stride, and more V2 (double dance) than V1 (single dance) skating across a race.

CONCLUSION

We propose that skiers at all levels can improve their performance with more specific training in techniques (i.e., maintaining long cycles without compromising cycle rate and selecting appropriate techniques) in combination with training for endurance and more strength. Furthermore, we would advise less experienced skiers and/or those with lower levels of performance to apply a more even pacing strategy rather than a positive one (i.e., starting the race too fast).

Differences in pacing of cross-country skiers by nationality - The example of Vasaloppet 2004-2017

It has been previously observed that athletes of certain origin nationality dominate particular sports; however, this phenomenon has been less studied in cross-country (XC) skiing, especially with regards to performance-related aspects, such as pacing. The aim of the present study was to examine the effect of nationality on pacing strategies of XC skiers who finished the "Vasaloppet" from 2004 to 2017. We studied 183,919 finishers (19,465 women and 164,454 men), classified into 15 nationalities, i.e. nationalities with number of finishers larger than 0.25% of the total number of finishers. In women, athletes from Russia (7:47:46 h:min:s) were the fastest and athletes from Denmark (10:01:03 h:min:s) the slowest (p < 0.001, η² = 0.057). In men, athletes from Russia (6:33:03 h:min:s) were the fastest and athletes from Denmark (9:03:27 h:min:s) the slowest (p < 0.001, η² = 0.069). In women and men, a small nationality× split interaction on speed was observed (p < 0.001, η² = 0.016-0.019) with Russians presenting a more even pacing compared to their slower counterparts. It was concluded that fast nationalities present a more even pacing, which should be attributed to the general trend of fast athletes for a more even pacing.

Pacing strategies by age in marathon cross-country skiing

OBJECTIVES

Pacing strategies have mainly been investigated for runners, but little is known for cross-country skiers. The aim of the present study was to investigate whether differences in pacing strategies do exist between younger and older cross-country skiers competing in the 42 km 'Engadin Ski Marathon'.

METHODS

Pacing was studied in 105,565 cross-country skiers (classified in 5-year age groups) competing between 1998 and 2016 in this race by examining changes of mean section velocity in 10 km (Change A, i.e. 100×(velocity in the 10-20 km section - velocity in the 0-10 km section)/velocity in the 0-10 km section), 20 km (Change B) and 35 km (Change C).

RESULTS

A small sex×distance (i.e. Change A versus Change B versus Change C) interaction on change of velocity was shown (P < .001, η² = 0.016), with women showing a less even pacing than men. In women, there was a trivial main effect of age group on Change A (P < .001, η² = 0.008) with a smaller decrease in velocity in age group <20 (-7.4%) and larger decrease in velocity in age group 75-79 (-12.8%), and Change B (P = .006, η² = 0.004) with smaller increase in velocity in age group 75-79 (+30.6%) and larger increase in velocity in age group 40-44 (+37.7%), but not on Change C (P = .784, η² = 0.003). In men, a small main effect of age group on Change A was shown (P < .001, η² = 0.019), with a smaller decrease of velocity in age group <20 (-3.5%) and larger in age group 70-74 (-10.5%). Trivial main effects of age group on Change B (P < .001, η² = .002), with a smaller increase of velocity in age group 85-89 (+25.8%) and larger increase in age group 70-74 (+33.0%), and Change C (P < .001, η² = 0.003), with smaller decrease of velocity in age group 85-89 (-38.2%) and larger decrease in age group 80-84 (-41.0%), were found.

CONCLUSIONS

Based on these findings, it was concluded that men and young cross-country skiers had a more even pacing than women and older cross-country skiers, which was in contrast with previous findings in other endurance sports, suggesting that the sex- and age-related differences in pacing might be sport-dependent.

The Age of Peak Marathon Performance in Cross-Country Skiing-The "Engadin Ski Marathon"

Knechtle, B and Nikolaidis, PT. The age of peak marathon performance in cross-country skiing-the "Engadin Ski Marathon." J Strength Cond Res 32(4): 1131-1136, 2018-The age of the best endurance performance has been well investigated in flat city running marathons. However, we have no knowledge about the age of peak marathon performance in cross-country skiing, which would be of great practical value for athletes and coaches. Therefore, the aim of the present study was to examine the age of peak marathon performance in cross-country skiing. Participants were 162,991 men and 34,833 women competing between 1998 and 2016 in the "Engadin Ski Marathon." We considered the fastest for both women and men, and all finishers in 1-year age intervals. The men-to-women ratio increased across ages (r = 0.55, p < 0.0001). Men (44.27 ± 0.03 years, 15.73 ± 0.01 km·h) were 5.98 ± 0.07 years older and 2.14 ± 0.02 km·h faster (p < 0.0001) than women (38.29 ± 0.06 years, 13.58 ± 0.01 km·h). Considering the fastest participants in 1-year age intervals, the fastest speed for men (30.33 km·h) was achieved at the age of 29 years, and for women (28.76 km·h) at the age of 24 years. Considering all participants, the fastest speed for men (17.69 km·h) was observed at the age of 18 years, whereas for women (15.76 km·h) it was at the age of 17 years. In summary, for athletes and coaches, the age of peak performance in cross-country skiers competing in a marathon distance was much younger and closer to the peak of aerobic capacity than what was found by previous studies in marathon road runners.

Following a Long-Distance Classical Race the Whole-Body Kinematics of Double Poling by Elite Cross-Country Skiers Are Altered

Introduction: Although short-term (approximately 10-min) fatiguing DP has been reported not to alter the joint kinematics or displacement of the centre of mass (COM) of high-level skiers, we hypothesize that prolonged DP does change these kinematics, since muscular strength is impaired following endurance events lasting longer than 2 h.

Methods: During the 58-km Marcialonga race in 2017, the fastest 15 male skiers were videofilmed (100 fps, FHD resolution in the sagittal plane) on two 20-m sections (inclines: 0.7 ± 0.1°) 48 km apart (i.e., 7 and 55 km from the start), approximating 50- km Olympic races. The cameras were positioned perpendicular to and about 40 m from the middle of each section and spatial dimensions adjusted for each individual track skied. Pole and joint kinematics, as well as displacement of the COM during two DP cycles were assessed.

Results: The 10 skiers who fulfilled our inclusion criteria finished the race in 2 h 09 min 19 s ± 28 s. Displacements of the joints and COM were comparable to previous observations on skiers roller skiing on a flat treadmill at similar speeds in the laboratory. 55 km after the start, cycle velocity and length were lower (P < 0.001 and P = 0.002, respectively) and the angular range of elbow joint flexion during the initial part of the poling phase reduced, while shoulder angle was greater during the first 35% of the DP cycle (all P < 0.05). Moreover, the ankle angle was increased and forward displacement of the COM reduced during the first 80% of the cycle.

Conclusion: Prolonged DP reduced the forward displacement of the COM and altered arm kinematics during the early poling phase. The inefficient utilization of COM observed after 2 h of competition together with potential impairment of the stretch-shortening of arm extensor muscles probably attenuated generation of poling force. To minimize these effects of fatigue, elite skiers should focus on maintaining optimal elbow and ankle kinematics and an effective forward lean during the propulsive phase of DP.

The effect of aging on pacing strategies of cross-country skiers and the role of performance level

Background

The participation of master cross-country (XC) skiers in training and competition has increased during the last decades; however, little is known yet about whether these athletes differ from their younger counterparts in aspects of performance such as pacing. Therefore, the aim of the present study was to examine the combined effect of age and performance (race time) on pacing in cross-country (XC) skiing. We analyzed all finishers (n = 79,722) in ‘Vasaloppet’ from 2012 to 2017, the largest cross-country skiing race in the world, classified according to their race time into 10 groups: 3-4 h, 4-5 h, ..., 12-13 h.

Results

A trivial main effect of sex on total pace range was observed (p < 0.001, η² = 0.002), where women (44.1 ± 10.2%) had larger total pace range than men (40.9 ± 11.8%). A large main effect of performance group on total pace range was shown (p < 0.001, η² = 0.160), where the smallest total pace range was 21.8 ± 1.9% (3-4 h group) and the largest 50.1 ± 9.9% (10-11 h group). A trivial sex×performance group interaction on total pace range was found (p < 0.001, η² = 0.001) with the largest sex difference in pacing shown in 9-10 h group. A trivial and small main effect of age was found in women (p < 0.001, η² = 0.005) and men (p < 0.001, η² = 0.011), respectively, where the masters had smaller total pace range than their younger counterparts. A trivial age group×performance group interaction on total pace range was observed in both women (p < 0.001, η² = 0.008) and men (p < 0.001, η² = 0.006) with smaller differences among age groups in the faster performance groups.

Conclusions

In summary, master XC skiers adopted a relatively even pacing independently from their race time and the differences in pacing from the younger XC skiers were more pronounced in the slower masters. These findings suggest that exercise attenuates the decline of performance in master XC skiers as shown by the similar pacing strategies between fast master XC skiers and their younger counterparts.

Sex Differences in World-Record Performance: The Influence of Sport Discipline and Competition Duration

The current review summarizes scientific knowledge concerning sex differences in world-record performance and the influence of sport discipline and competition duration. In addition, the way that physiological factors relate to sex dimorphism is discussed. While cultural factors played a major role in the rapid improvement of performance of women relative to men up until the 1990s, sex differences between the world’s best athletes in most events have remained relatively stable at approximately 8–12%. The exceptions are events in which upper-body power is a major contributor, where this difference is more than 12%, and ultraendurance swimming, where the gap is now less than 5%. The physiological advantages in men include a larger body size with more skeletal-muscle mass, a lower percentage of body fat, and greater maximal delivery of anaerobic and aerobic energy. The greater strength and anaerobic capacity in men normally disappear when normalized for fat-free body mass, whereas the higher hemoglobin concentrations lead to 5–10% greater maximal oxygen uptake in men with such normalization. The higher percentage of muscle mass in the upper body of men results in a particularly large sex difference in power production during upper-body exercise. While the exercise efficiency of men and women is usually similar, women have a better capacity to metabolize fat and demonstrate better hydrodynamics and more even pacing, which may be advantageous, in particular during long-lasting swimming competitions.

The Russians Are the Fastest in Marathon Cross-Country Skiing: The "Engadin Ski Marathon"

It is well known that athletes from a specific region or country are dominating certain sports disciplines such as marathon running or Ironman triathlon; however, little relevant information exists on cross-country skiing. Therefore, the aim of the present study was to investigate the aspect of region and nationality in one of the largest cross-country skiing marathons in Europe, the “Engadin Ski Marathon.” All athletes (n = 197,125) who finished the “Engadin Ski Marathon” between 1998 and 2016 were considered. More than two-thirds of the finishers (72.5% in women and 69.6% in men) were Swiss skiers, followed by German, Italian, and French athletes in both sexes. Most of the Swiss finishers were from Canton of Zurich (20.5%), Grisons (19.2%), and Berne (10.3%). Regarding performance, the Russians were the fastest and the British the slowest. Considering local athletes, finishers from Canton of Uri and Glarus were the fastest and those from Canton of Geneva and Basel the slowest. Based on the findings of the present study, it was concluded that local athletes were not the fastest in the “Engadin Ski Marathon.” Future studies need to investigate other cross-country skiing races in order to find the nationalities and regions of the fastest cross-country skiers.