Kerry McGawley

Mid Sweden University · Swedish Winter Sports Research Center (SWSRC)

Background Most sex comparisons in endurance sports have been derived from performance-matched groups of female and male athletes competing over similar distances within summer sports. Corresponding analyses of sex differences in winter endurance sports have not previously been conducted. In the Olympic Winter Games (OWG), the endurance sports incl...

The International Olympic Committee’s (IOC) consensus statement on ‘methods for recording and reporting of epidemiological data on injury and illness in sport’ recommended standardising methods to advance data collection and reporting consistency. However, additional aspects need to be considered when these methods are applied to specific sports se...

Background This study used metabolic phenotyping to explore the responses of highly-trained cross-country skiers to a standardized exercise test, which was part of the athletes’ routine testing, and determine whether metabolic phenotyping could discriminate specific physiological, performance, and illness characteristics. Methods Twenty-three high...

Background: In the last decade, a growing body of research has focused on the many aspects and challenges of combining parenthood with elite sport. Although the number of father-athletes is significantly higher than the number of mother-athletes, few studies to date have focused on male athletes’ experiences in a parenting context. Aim: The aims o...

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent...

Background Metabolomics has potential to highlight novel pathways and biomarkers of interest to provide early warning signs of health problems, such as opportunistic infection susceptibility among athletes. Objective To investigate differences in metabolites at rest and in response to exercise among athletes susceptible and not susceptible to oppo...

Challenges facing mother-athletes (MAs) have aroused research and media attention in recent years, with an increasing number of sportswomen attempting to successfully combine pregnancy and motherhood with an elite athletic career. The aims of this study were to explore how MA-specific challenges manifest in elite cross-country skiing in Scandinavia...

Aim To identify how riding rein direction (left and right) and rider asymmetry affect tölt performance in Icelandic horses. Methods Two horses were ridden in tölt by four riders on both left and right reins. Riders wore pressure insoles that measured the total absolute force (FAbs) and absolute force difference (FDiff) in their left and right feet...

Background: Elite sport is continuously evolving. World records keep falling and athletes from a longer list of countries are involved. Purpose: This commentary was designed to provide insights into present and future trends associated with world-class endurance training based on the perspectives, experience, and knowledge of an expert panel of...

Purpose: To determine whether competitive performance, as defined by International Biathlon Union (IBU) and International Ski Federation (FIS) points in biathlon and cross-country (XC) skiing, respectively, can be projected using a combination of anthropometric and physiological metrics. Shooting accuracy was also included in the biathlon models....

Menstrual health represents a state of complete physical, mental, and social well-being in relation to a woman's menstrual cycle. From a health literacy perspective, knowledge acquisition and expertise are dependent upon the degree to which an individual can find, access, understand, critically analyse, and apply health information. Therefore, mens...

The aim was to investigate whether rifle carriage affects gear distribution during on-snow skiing in highly-trained biathletes, and whether there were any associated sex differences. Twenty-eight biathletes (11 women, 17 men) skied a 2230-m lap at competition speed twice, one lap with the rifle (WR) and the other lap without the rifle (NR). The bia...

Frontal midline theta power (FMT) has been associated with superior rifle shooting performance. Our experiment examined whether electroencephalographic-based training could increase FMT, shooting performance, and attentional focus in highly trained/elite biathletes. Participants ( n = 28; age, M = 21.7, SD = 2.3) were assigned to a control group or...

Purpose: This study aimed to investigate how rifle carriage and skiing speed during biathlon roller-skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist ), as well as possible sex differences associated with rifle carriage. Methods: Fourteen biathletes...

Objective Few long-term prospective studies have investigated health problems in elite competitive cross-country (XC) skiers. Hence, our objective was to compare the prevalence of health problems in national team XC skiers over a competitive season. Methods Forty national team XC skiers participated in this prospective, observational study. Two gr...

Introduction Dietary inorganic nitrate is a popular nutritional supplement, which increases nitric oxide bioavailability and may improve exercise performance. Despite over a decade of research into the effects of dietary nitrate supplementation during exercise there is currently no expert consensus on how, when and for whom this compound could be r...

Objective: To monitor the daily variations and time course of changes in selected variables during a 17–21-day altitude training camp at 1,800 m in a group of elite cross-country skiers (9 women, 12 men) and biathletes (7 women, 4 men). Methods: Among other variables, resting peripheral oxygen saturation (SpO2rest), resting heart rate (HRrest) and...

Background Beetroot juice (BJ) and caffeine (CAF) are considered as ergogenic aids among athletes to enhance performance, however, the ergogenic effects of BJ and CAF co-ingestion are unclear during team-sport-specific performance. This study aimed to investigate the acute effects of BJ and CAF co-ingestion on team-sport-specific performance, compa...

This study examined the micro-pacing strategies during a distance freestyle cross-country (XC) skiing competition. Nine female and 10 male highly trained XC skiers wore a GNSS device during a FIS-sanctioned race. The course was ~4900 m; women completed two-laps; men completed three-laps. The course was divided into uphill (S1, S3, S5, S7), downhill...

Purpose: To examine the influence of menstrual cycle (MC) and hormonal contraceptive (HC) cycle phases on physiological variables monitored during incremental treadmill testing in physically active women (eumenorrheic, EUM = 16 and monophasic HC-users, CHC = 12). Methods: Four running tests to exhaustion were performed at bleeding, mid follicular (...

This study aimed to determine whether the recently developed Flow Motion Technology ® roller-ski prototype could improve indicators of performance during sub-maximal and maximal cross-country roller skiing. Thirteen national and international cross-country skiers completed 2 experimental trials: 1 with Flow Motion Technology ® activated, allowing a...

Background: In a sprint cross-country (XC) ski competition, the difference in recovery times separating the first and the second semi-final (SF) heats from the final (F) may affect performance. The aim of the current study was to compare the effects of longer vs. shorter recovery periods prescribed between the 3 knock-out races of a simulated sprin...

Competitive female athletes perceive their hormonal cycles to affect their training, competition performance and overall well-being. Despite this, athletes rarely discuss hormonal-cycle-related issues with others. The aim of this study was to gain an in-depth understanding of the perceptions and experiences of endurance athletes and their coaches i...

Background A limited number of long-term prospective studies have investigated health problems in competitive cross-country skiers. Moreover, limited information exists regarding differences in the prevalence and severity of health problems between senior and development female and male cross-country skiers. Objective To compare the prevalence and...

Objectives: To observe changes in sleep from baseline and during an altitude training camp in elite endurance athletes. Design: Prospective, observational. Setting: Baseline monitoring at <500 m for 2 weeks and altitude monitoring at 1800 m for 17-22 days. Participants: Thirty-three senior national-team endurance athletes (mean age 25.8 ± S....

Purpose: To provide a descriptive analysis of the warm-up (WU) strategies employed by cross-country skiers prior to distance and sprint competitions at a national championship and to compare the skiers' planned and executed WUs prior to the respective competitions. Methods: Twenty-one national- and international-level skiers (11 women and 10 men...

Introduction To date, no study has compared anaerobic capacity (AnC) estimates computed with the maximal accumulated oxygen deficit (MAOD) method and the gross energy cost (GEC) method applied to treadmill running exercise. Purpose Four different models for estimating anaerobic energy supply during treadmill running exercise were compared. Method...

Purpose: This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods: Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2...

Skeletal muscle fiber composition and capillary density influence physical performance and whole-body metabolic properties. ~45% of the variance in fiber type is heritable, which motivated us to perform a genome-wide association study of skeletal muscle histology from 656 Swedish men. Four independent variants were associated ( p < 5x10 − 8 ) with...

Purpose: To describe changes in laboratory-assessed anthropometric and physiological characteristics, training volumes and competitive performance in national development-team cross-country (XC) skiers over a 25-month period, and to analyze whether changes in competitive performance could be predicted by changes in laboratory-assessed qualities an...

Splenic contraction, which leads to ejection of stored erythrocytes, is greater in athletes involved in regular freediving or high-altitude activities. As this response facilitates oxygen carrying capacity, similar characteristics may be expected of elite endurance athletes. Therefore, our aims were to compare resting and apnea-induced splenic volu...

Purpose The purpose was to investigate whether an increased amount of training while carrying the rifle affects skiing in well-trained biathletes at submaximal and maximal workloads during a pre-season period lasting a minimum of 12 weeks. Methods Seventeen well-trained biathletes (9 females, 8 males) were assigned to an intervention (IG, n = 10)...

Objective This study aimed to describe the endurance training and incidence of illnesses reported by a group of well-trained cross-country (XC) skiers throughout their transition from junior to senior level. Methods Changes in self-reported training and performance, from 31 well-trained XC skiers, were analyzed from the start of the season they tu...

Purpose: To evaluate the effects of wearing upper- and lower-body compression garments on cross-country skiing performance in elite winter biathletes. Methods: A total of 7 senior biathletes (4 men and 3 women) from the Swedish national team performed 2 exercise trials in a randomized and counterbalanced order, wearing either commercially availa...

The associations between health problems and performance in elite cross-country skiers presented at the 2019 Nordic Winter Sports Conference.

Skiing in biathlon is a high-intensity, intermittent endurance discipline. This study aimed to evaluate the relationships between laboratory-derived physiological variables and skiing performance during a field-based biathlon competition (BC) for female and male biathletes. Fourteen female (23 ± 3 year, V˙O2max 56 ± 4 mL·kg−1·min−1) and 14 male (24...

The purpose of the present study was to analyze micro-pacing strategies in cross-country skiing, and their relation to section and total race times. Eleven competitive female cross-country skiers were tracked during a classic sprint time-trial race using a global navigation satellite system (GNSS) unit. A coordinate mapping procedure was applied to...

Balance as a skill and task-specific capacity is considered an essential physical quality in curling, required for executing effective stone delivery. However, no testing protocols have been developed to test curling-specific balance in the delivery position. Thus, the primary aim of this study was to investigate the reliability , validity and usef...

Context: Warming up in very cold climates and maintaining an elevated body temperature prior to a race is challenging for snow-sport athletes. Purpose: To investigate the effects of active (ACT), passive (PAS), and a combination of ACT and PAS (COM) warm-ups on maximal physical performance in a subzero environment among snow-sport athletes. Met...

Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and...

Purpose: This study aimed to investigate the physiological factors affected by rifle carriage during biathlon skiing performance, as well as the sex differences associated with rifle carriage. Methods: Seventeen national- and international-level biathletes (nine females and eight males; age 23.0 ± 3.3 years, V.O2max 59.4 ± 7.6 mL.kg–1.min–1) perfor...

Abstract Background Whilst the ergogenic effects of carbohydrate intake during prolonged exercise are well-documented, few investigations have studied the effects of carbohydrate ingestion during cross-country skiing, a mode of exercise that presents unique metabolic demands on athletes due to the combined use of large upper- and lower-body muscle...

Purpose: This study aimed to compare performance and pacing strategies between elite male and female cross-country skiers during a sprint competition on snow using the skating technique. Methods: Twenty male and 14 female skiers completed an individual time-trial prolog (TT) and three head-to-head races (quarter, semi, and final) on the same 1,572-...

This study investigated the energy, macronutrient and fluid intakes, as well as hydration status (urine specific gravity; USG), in elite cross-country skiers during a typical day of training (day one) and a sprint skiing competition the following day (day two). Thirty-one (18 male and 13 female) national team skiers recorded their food and fluid in...

This study investigated whether commercially available compression garments (COMP) exerting a moderate level of pressure and/or neuromuscular electrical stimulation (NMES) accelerate recovery following a cross-country sprint skiing competition compared with a control group (CON) consisting of active recovery only. Twenty-one senior (12 males, 9 fem...

Dietary supplements such as caffeine and beetroot juice are used by athletes in an attempt to optimize performance and therefore gain an advantage in competition. The aim of this study was to investigate the individual and combined effects of caffeine and beetroot-juice supplementation during submaximal and maximal treadmill running. Seven males (m...

Purpose: The present study aimed to compare four methods of estimating anaerobic energy production during supramaximal exercise. Methods: Twenty-one junior cross-country skiers competing at a national and/or international level were tested on a treadmill during uphill (7°) diagonal-stride (DS) roller-skiing. After a 4-minute warm-up, a 4 × 4-min co...

Exposure to altitude results in multiple physiological consequences. These include, but are not limited to, a reduced maximal oxygen consumption, drop in arterial oxygen saturation, and increase in muscle metabolic perturbations at a fixed sub-maximal work rate. Exercise capacity during fixed work rate or incremental exercise and time-trial perform...

The present study examined the effects of acute nitrate (NO3⁻) supplementation ingested in the form of concentrated beetroot juice on cross-country roller-ski performance in normoxia (N) and normobaric hypoxia (H). Eight competitive cross-country skiers (five males: age 22 ± 3 years, 71.5 ± 4.7 mL kg⁻¹·min⁻¹; three females: age 21 ± 1 years, 58.4 ±...

Introduction: The current study aimed to investigate the responses to block- versus evenly-distributed high-intensity interval training (HIT) within a polarized microcycle. Methods: Twenty well-trained junior cross-country skiers (10 males, age 17.6 ± 1.5 and 10 females, age 17.3 ± 1.5) completed two, 3-week periods of training (EVEN and BLOCK) in...

Introduction: Traditional graded-exercise tests to volitional exhaustion (GXTs) are limited by the need to establish starting workloads, stage durations, and step increments. Short-duration time-trials (TTs) may be easier to implement and more ecologically valid in terms of real-world athletic events. The purpose of the current study was to assess...

Habitual nutritional intakes in cross-country skiers have previously been reported (Fogelholm et al., 1992), however in elite cross-country skiers there is limited knowledge about racespecific nutritional practices, or the prevalence of dehydration and persistent low energy availability (EA). This study aimed to investigate, in the context of a sim...

Purpose: The aim of the current study was to investigate pacing strategies and the distribution of physiological resources in best versus worst performances during a series of 4-minute, self-paced running time-trials (RunTTs). Methods: Five male and five female recreational runners (age 32 ± 7 years) completed a sub-maximal ramp test and five Ru...

This study investigated carbohydrate ingestion of varied doses and frequencies during a simulated cross-country skiing time trial. Ten men and three women (age: 30 ± 7 years; V ˙ O 2 m a x : 59.6 ± 5.7 mL/kg/min) completed four, 30-km classic technique roller skiing time trials on a treadmill. A 1:1 maltodextrin-fructose carbohydrate solution was p...

Objectives Repeated-sprint ability appears to be influenced by oxidative metabolism, with reductions in fatigue and improved sprint times related to markers of aerobic fitness. The aim of the current study was to measure the oxygen uptake (V˙O2) during the first and last sprints during two, 5 x 6-s repeated-sprint bouts. Design Cross-sectional stu...

Cross-country ski races place complex demands on athletes, with events lasting between approximately 3 min and 2 h. The aim of the current study was to compare the aerobic and anaerobic measures derived from a short time-trial between male and female skiers using diagonal cross-country skiing. Twenty-four highly-trained cross-country skiers (12 mal...

Despite the wealth of evidence regarding physical training strategies in soccer, there is little information regarding soccer-specific concurrent training and the effects of training order. The current study aimed to: i) quantify the effects of concurrent high-intensity run-based training (HIT) and strength- and power-based training (STR) on soccer...

The well-established ergogenic benefit of ingesting carbohydrates during single-discipline endurance sports has only been tested once within an Olympic-distance (OD) triathlon. The aim of the present study was to compare the effect of ingesting a 2:1 maltodextrin/fructose solution with a placebo on simulated OD triathlon performance. Six male and 4...

The Wingate cycle test (WAnT) is a 30-s test commonly used to estimate anaerobic work capacity (AWC). However, the test may be too short to fully deplete anaerobic energy reserves. We hypothesized that a 90-s all-out isokinetic test (ISO_90) would be valid to assess both aerobic and anaerobic capacities in young females. Eight girls (11.9 ± 0.5 y)...

The purpose of this study was to establish whether critical power, as traditionally determined from the performance of three constant-load tests to exhaustion, is attained at the end of a 90-s all-out test in children. Sixteen healthy children (eight males and eight females; mean age 12.3 years, s(x) = 0.1; body mass 39.6 kg, s(x) = 1.8; peak VO(2)...

The purpose of the study was to identify critical power (CP) in boys and girls and to examine the physiological responses to exercise at and 10% above CP (CP+10%) in a sub-group of boys. Nine boys and 9 girls (mean age 12.3 (0.5)y performed 3 constant-load tests to derive CP. Eight of the boys then exercised, in random order, at CP and CP+10% until...

AimThe aim of this review was to state the use of critical power concept at different populations and to summarize studies reported data in order to highlight its interest for the aerobic abilities assessement.Conclusion The critical power determination is based on times to exhaustion at different exercise intensities. The synthesis of several stud...

The present study examined the reliability of work and power measures during a 5 × 6-s cycle ergometer test of repeated-sprint ability. Nine, well-trained, female soccer players performed five, 5 × 6-s repeated-sprint tests on a front-access cycle ergometer on separate days. Sprints were separated by 24 s of active recovery. Absolute measures of to...

Introduction: Increases in maximal oxygen uptake (VO2max), as a result of training, have been suggested to be linked with time spent at a high percentage of VO2max. The time spent between 90% and 100% of VO2max (tVO2max) depends upon the time to achieve VO2max and total exercise duration. During exercise in the severe exercise domain, VO2max is att...

Introduction Short sprints (< 6 s) have been identified as important components in team-sports, and may be critical to a team's success(1). Rather than being distributed at regular intervals throughout the course of a game, sprints are unpredictable and often occur in bouts(2). A bout of repeated-sprints has been characterised by a decline in sprin...