Psychological Determinants in Biathlon Performance: A U23 National Team Case Study

BACKGROUND

The present investigation examined what psychological factors athletes perceived to impact their competition performance and what training strategies and focus the athletes considered to be the most important.

METHODS

We recruited six participants (three females, three males) from the Norwegian Biathlon Federation's national U23 and junior teams, and all participated. We used semi-structured interviews to gather the data and used thematic analyses to examine our findings.

RESULTS

The findings centered around the intricate relationship between psychological factors, particularly self-efficacy, anxiety, attention control, and performance, in biathlon shooting.

CONCLUSIONS

Implementing a holistic approach to biathlon training entails harmonizing physical and psychological elements with personalized psychological training regimens.

Test-retest reliability of ski-specific aerobic, sprint, and neuromuscular performance tests in highly trained cross-country skiers

PURPOSE

Laboratory tests are commonly performed by cross-country (XC) skiers due to the challenges of obtaining reliable performance indicators on snow. However, only a few studies have reported reliability data for ski-specific test protocols. Therefore, this study examined the test-retest reliability of ski-specific aerobic, sprint, and neuromuscular performance tests.

METHODS

Thirty-nine highly trained XC skiers (26 men and 13 women, age: 22 ± 4 years, V̇O2max : 70.1 ± 4.5 and 58.8 ± 4.4 mL·kg-1 ·min-1 , respectively) performed two test trials within 6 days of a diagonal V̇O2max test, n = 27; skating graded exercise test to assess the second lactate threshold (LT2 ), n = 27; 24-min double poling time trial (24-min DP, n = 25), double poling sprint test (SprintDP1 , n = 27), and 1-min self-paced skating sprint test (Sprint1-min , n = 26) using roller skis on a treadmill, and an upper-body strength test (UB-ST, n = 27) to assess peak power (Ppeak ) with light, medium, and heavy loads. For each test, the coefficient of variation (CV), intraclass correlation coefficient (ICC), and minimal detectable change (MDC) were calculated.

RESULTS

V̇O2max demonstrated good-to-excellent reliability (CV = 1.4%; ICC = 0.99; MDC = 112 mL·min-1 ), whereas moderate-to-excellent reliability was found for LT2 (CV = 3.1%; ICC = 0.95). Performance during 24-min DP, SprintDP1 , and Sprint1-min showed good-to-excellent reliability (CV = 1.0%-2.3%; ICC = 0.96-0.99). Absolute reliability for UB-ST Ppeak was poor (CV = 4.9%-7.8%), while relative reliability was excellent (ICC = 0.93-0.97) across the loads.

CONCLUSION

In highly trained XC skiers, sport-specific aerobic and sprint performance tests demonstrated high test-retest reliability, while neuromuscular performance for the upper body was less reliable. Using the presented protocols, practitioners can assess within- and between-season changes in relevant performance indicators.

International biathlon season during the COVID-19 pandemic was based on frequent on-site PCR-testing protocol with rapid result management

The resumption of professional sports during the COVID-19 pandemic has been described in team sports but less in individual sports. The International Biathlon Union implemented a COVID-19 concept for the 2020-2021 season aimed to mitigate the risks of transmission by rules designated for the professional biathlon environment. The "bubble" model was based on regular reverse transcript polymerase chain reaction (PCR) testing with rapid results and efficient result management protocol. The objective of this study was report incidence and transmission of SARS-CoV-2 among professional biathletes and staff undergoing frequent PCR testing and risk reduction measures during the international season 2020-2021. The efficiency of risk mitigation measures was also evaluated based on the incidence data. During the 4-month season, altogether 22,182 SARS-CoV-2 PCR tests were conducted on all individuals participating in international biathlon season (athletes, team staff and organizing committee). Ninety-six (0.4%) PCR tests were positive and 30% of the positive PCR tests were considered "persistent positive" following recovery from a recent COVID-19 infection. No transmission events were detected following contact with "persistent positive" cases during the season. A great majority of the positive PCR tests were recorded during the first days after arrival in the "bubble", often in the first entry test taken by the on-site laboratory. In conclusion, a "bubble model" based on frequent PCR testing and hygiene rules was efficient in keeping the infection rate low. The competition activity including international travel was safe, and most of the infections seemed to originate from outside of the "bubble".

Heart Rate-Blood Lactate Profiling in World-Class Biathletes During Cross-Country Skiing: The Difference Between Laboratory and Field Tests

PURPOSE

To identify differences in heart rate (HR) and concentration of blood lactate ([La]) relationships between laboratory- and field-based skate-roller-skiing tests.

METHODS

Fourteen world-class biathletes (8 women, 6 men) completed a laboratory- and field-based roller-skiing test using the skate technique. The laboratory-based test comprised 5 to 7 submaximal steps at a fixed incline and speed on a roller-skiing treadmill. The field-based test comprised 5 steps on a course where the final hill was designed to mimic the conditions of the laboratory test. HR and [La] were measured for each step. The HR associated with 2 mmol·L-1 (HR@2 mmol) and 4 mmol·L-1 (HR@4 mmol) of [La] was calculated using an interpolation method. A 1-way analysis of variance and Bland-Altman analyses with 95% limits of agreement (LoA) were used to determine if test type influenced HR@2 mmol or HR@4 mmol. A second-order polynomial was fitted to group-level data to highlight the HR-[La] relationships for laboratory- and field-based tests.

RESULTS

HR@2 mmol was lower for field tests than for laboratory tests (mean bias: 1.9%HRmax; 95% LoA: -4.5 to +8.3%HRmax; P < .001). HR@4 mmol was also lower for field tests compared to laboratory tests (mean bias: 2.4%HRmax; 95% LoA: -1.2 to +6.0%HRmax; P < .001). On the group level, the lactate threshold occurred at a lower HR during roller skiing in the field compared to the laboratory.

CONCLUSIONS

The findings from this study confirm that for a given HR, [La] was greater in field- compared with laboratory-based conditions. These results might have implications for how coaches define training-intensity "zones" during skate roller skiing based on laboratory tests.

Physiological Aspects of World Elite Competitive German Winter Sport Athletes

Nine Ski mountaineering (Ski-Mo), ten Nordic-Cross Country (NCC) and twelve world elite biathlon (Bia) athletes were evaluated for cardiopulmonary exercise test (CPET) performance as the primary aim of our descriptive preliminary report. A multicenter retrospective analysis of CPET data was performed in 31 elite winter sports athletes, which were obtained in 2021 during the annual medical examination. The matched data of the elite winter sports athletes (14 women, 17 male athletes, age: 18–32 years) were compared for different CPET parameters, and athlete’s physique data and sport-specific training schedules. All athletes showed, as estimated in elite winter sport athletes, excellent performance data in the CPET analyses. Significant differences were revealed for VE _VT2 (respiratory minute volume at the second ventilatory threshold (VT2)), highest maximum respiratory minute volume (VE_maximum), the indexed ventilatory oxygen uptake (VO₂) at VT2 (VO₂/kg _VT2), the oxygen pulse at VT2, and the maximum oxygen pulse level between the three professional winter sports disciplines. This report provides new evidence that in different world elite winter sport professionals, significant differences in CPET parameters can be demonstrated, against the background of athlete’s physique as well as training control and frequency.

Orofacial conditions and oral health behavior of young athletes - a comparison of amateur and competitive sports

PURPOSE

This retrospective cross-sectional study aimed to evaluate oral health status (dental, periodontal and functional) and oral health behavior in young German athletes including the comparison of competitive (CA) and amateur sports (AA).

METHODS

Data of CA (German national teams, perspective and youth squads) and AA aged between 18 and 30 years with an available oral examination in 2019 were included. Clinical examination: caries experience (DMF-T), non-carious wear (erosion, BEWE), partially erupted wisdom teeth, gingival inflammation (PBI), plaque index, periodontal screening (PSI), and temporomandibular dysfunction (TMD) screening. Questionnaires: oral health behavior, periodontal symptoms.

RESULTS

88 CA (w = 51 %, 20.6 ± 3.5 years) of endurance sports and 57 AA (w = 51%, 22.2 ± 2.1 years) were included. DMF-T was comparable (CA: 2.7 ± 2.2, AA: 2.3 ± 2.2; p = 0.275) with more D-T in CA (0.6 ± 1.0) than AA (0.3 ± 0.7; p = 0.046; caries prevalence: CA: 34 %, AA: 19 %; p = 0.06). Both groups had low severity of erosion (BEWE about 3.5). CA had more positive TMD screenings (43 % vs. 25 %; p = 0.014). In both groups, all athletes showed signs of gingival inflammation, but on average of low severity (PBI < 1). More CA needed complex periodontal treatment than AA (maximum PSI = 3 in 40% vs. 12%; p < 0.001). Oral health behavior was comparable (daily tooth brushing, regular dental check-ups in > 70%).

CONCLUSIONS

Young German athletes (CA and AA) generally showed signs of gingival inflammation and needed to improve their oral health behavior. CA showed slightly increased oral findings (more D-T, periodontal and TMD screening findings) than AA, but similar oral health behavior. This may imply an increased dental care need in competitive sports.

Performance-determining factors in biathlon prone shooting without physical stress

This study investigated the most important factors determining biathlon prone shooting performance. Ten female and 16 male biathletes (age 19.9 ± 2.9 years) from the national teams of Finland and Vuokatti-Ruka Sports Academy performed 6 × 5 biathlon prone shooting shots without physical stress under laboratory conditions. Shooting performance and multiple aiming point trajectory variables were measured together with an analysis of triggering force. Based on the aiming point trajectory data principal component analysis, we identified four technical components in biathlon prone shooting: stability of hold, aiming accuracy, cleanness of triggering, and timing of triggering. Multiple regression analysis (MRA) further determined that cleanness of triggering, aiming accuracy, and timing of triggering accounted for 80% of mean shooting performance (p < 0.001). Better stability of hold, aiming accuracy and cleanness of triggering were directly associated with better shooting performance (0.62 ≤ |r| ≥0.79, all p < 0.001). Better stability of hold measures were also associated with better cleanness of triggering, and higher pre-shot trigger force levels were associated with better stability of hold and cleanness of triggering. These results indicate that with both direct and indirect effects on performance, stability of hold seems to be a general prerequisite for successful biathlon shooting. The results also highlight the importance of aiming accuracy, cleanness and timing of triggering, along with a high pre-shot trigger force level. The variables identified in this study could be used to assess biathletes' performance in the most relevant shooting technical aspects to guide the emphasis of their shooting training.

An observational study of sleep characteristics in elite endurance athletes during an altitude training camp at 1800 m

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.D. 2.8 years, 16 women).

MEASUREMENTS

Daily measurements of sleep (using a microwave Doppler radar at baseline and altitude), oxygen saturation (SpO₂), training load and subjective recovery (at altitude).

RESULTS

At altitude vs. baseline, sleep duration (P = .036) and light sleep (P < .001) decreased, while deep sleep (P < .001) and respiration rate (P = .020) increased. During the first altitude week vs. baseline, deep sleep increased (P = .001). During the first vs. the second and third altitude weeks, time in bed (P = .005), sleep duration (P = .001), and light sleep (P < .001) decreased. Generally, increased SpO₂ was associated with increased deep sleep while increased training load was associated with increased respiration rate.

CONCLUSION

This is the first study to document changes in sleep from near-sea-level baseline and during a training camp at 1800 m in elite endurance athletes. Ascending to altitude reduced total sleep time and light sleep, while deep sleep and respiration rate increased. SpO₂ and training load at altitude were associated with these responses. This research informs our understanding of the changes in sleep occurring in elite endurance athletes attending training camps at competition altitudes.

Effects of Increased Load of Low- Versus High-Intensity Endurance Training on Performance and Physiological Adaptations in Endurance Athletes

PURPOSE

To compare the effects of increased load of low- versus high-intensity endurance training on performance and physiological adaptations in well-trained endurance athletes.

METHODS

Following an 8-week preintervention period, 51 (36 men and 15 women) junior cross-country skiers and biathletes were randomly allocated into a low-intensity (LIG, n = 26) or high-intensity training group (HIG, n = 25) for an 8-week intervention period, load balanced using the overall training impulse score. Both groups performed an uphill running time trial and were assessed for laboratory performance and physiological profiling in treadmill running and roller-ski skating preintervention and postintervention.

RESULTS

Preintervention to postintervention changes in running time trial did not differ between groups (P = .44), with significant improvements in HIG (-2.3% [3.2%], P = .01) but not in LIG (-1.5% [2.9%], P = .20). There were no differences between groups in peak speed changes when incremental running and roller-ski skating to exhaustion (P = .30 and P = .20, respectively), with both modes being significantly improved in HIG (2.2% [3.1%] and 2.5% [3.4%], both P < .01) and in roller-ski skating for LIG (1.5% [2.4%], P < .01). There was a between-group difference in running maximal oxygen uptake changes (P = .04), tending to improve in HIG (3.0% [6.4%], P = .09) but not in LIG (-0.7% [4.6%], P = .25). Changes in roller-ski skating peak oxygen uptake differed between groups (P = .02), with significant improvements in HIG (3.6% [5.4%], P = .01) but not in LIG (-0.1% [0.17%], P = .62).

CONCLUSION

There was no significant difference in performance adaptations between increased load of low- versus high-intensity training in well-trained endurance athletes, although both methods improved performance. However, increased load of high-intensity training elicited better maximal oxygen uptake adaptations compared to increased load of low-intensity training.

Prevalence and Incidence of Injury during Olympic-style Shooting Events: A Systematic Review

BACKGROUND

Shooting sports are included in collegiate and Olympic events. However, there is minimal evidence examining injury prevalence and incidence for these athletes.

HYPOTHESIS/PURPOSE

The purpose of this study was to systematically review the literature to examine the available evidence regarding the incidence, prevalence, and types of injuries that affect athletes in Olympic-style shooting events.

STUDY DESIGN

Systematic review.

METHODS

The electronic databases PubMed, Cochrane Library, Cinahl, MEDLINE, and SPORTDiscus were searched utilizing terms related to shooting and injuries. Studies were included if they reported prevalence or incidence of injury in collegiate or Olympic shooting events, and were excluded if inclusion criteria were not met, full text was unavailable, or not in English. Two reviewers independently screened articles in two phases: 1) screening of titles/abstracts 2) full text review. A third reviewer resolved conflicts.

RESULTS

Nineteen studies were ultimately included. The sports identified were biathlon, rifle, pistol, and shotgun. Shooting events in both winter and summer Olympics had low percentages of injuries compared to other sports. Winter shooting events had a higher percentage of injuries (6.9%) compared to summer (2.3%). In summer, females demonstrated a higher percentage of injuries (6.9%) compared to males (1.7%). In winter, males had a higher percentage of injuries (8.6%) versus females (5.1%).

CONCLUSION

Injury incidence and prevalence was low for athletes in shooting sports in the Olympics. Injury rate was higher in the winter Olympic shooting events likely from increased physiological demand. With injury surveillance focusing on acute injuries rather than chronic, the number of injuries may be underestimated. Females had higher injury rates than males in the summer Olympics while the opposite was observed in the winter Olympics, likely from sex differences and differences in physiological demand for each event.

LEVEL OF EVIDENCE

Level 3.

Enhanced splenic volume and contraction in elite endurance athletes

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 volume in endurance athletes and untrained individuals, and to assess the athletes' exercise-induced splenic volume. Twelve elite biathletes (7 women) and 12 controls (6 women) performed a maximal effort apnea in a seated position. In addition, the biathletes completed a maximal roller-skiing time trial. Splenic dimensions were measured by ultrasonic imaging for subsequent volume calculations, whereas Hb was analyzed from capillary blood samples and cardiorespiratory variables were monitored continuously. Baseline splenic volume was larger in the biathletes (214 ± 56 mL) compared with controls (157 ± 39 mL, P = 0.008) and apnea-induced splenic contraction was also greater in the biathletes (46 ± 20 mL vs. 30 ± 16 mL, P = 0.035). Hb increased immediately after apnea in the biathletes (4.5 ± 4.8%, P = 0.029) but not in the controls (-0.7 ± 3.1%, P = 0.999). Increases in exercise-induced splenic contraction (P = 0.008) and Hb (P = 0.001) were greater compared with the apnea-induced responses among the athletes. Baseline splenic volume tended to be correlated with V̇o_2max (r = 0.584, P = 0.059). We conclude that elite biathletes have greater splenic volume with a greater ability to contract and elevate Hb compared with untrained individuals. These characteristics may transiently enhance O₂-carrying capacity and possibly increase O₂ uptake, thereby helping biathletes to cope with high intermittent O₂ demands and severe O₂ deficits that occur during biathlon training and competition.NEW & NOTEWORTHY This study demonstrates that elite biathletes have larger splenic volume, apnea-induced splenic contraction, and Hb elevation compared with untrained individuals, which is likely functional to cope with high O₂ demands and substantial O₂ deficits. We believe that enhanced splenic contraction may be of importance during competitions involving cross-country skiing, to regulate circulating Hb and enhance O₂-carrying capacity, which may protect [Formula: see text] and increase O₂ uptake.

"When I Sleep Poorly, It Impacts Everything": An Exploratory Qualitative Investigation of Stress and Sleep in Junior Endurance Athletes

On their journeys toward senior athletic status, junior endurance athletes are faced with a multitude of stressors. How athletes react to stressors plays a vital part in effective adaptation to the demanding, ever-changing athletic environment. Sleep, the most valued recovery strategy available to athletes, has the potential to influence and balance athletic stress, and enable optimal functioning. However, sleep is sensitive to disturbances by stress, which is described by the concept of sleep reactivity. Among athletes, poor sleep quality is frequently reported, but our understanding of the associations between stress and sleep in junior athletes is currently incomplete. The present study therefore investigated the themes of stress and sleep, and the associations between these variables with the use of in-depth semi-structured interviews in six junior endurance athletes (three men and three women, mean age 17.7 ± 0.5 years). Data was analyzed qualitatively based on the Grounded Theory. The qualitative material was supplemented with quantitative data on subjective sleep quality (Pittsburg Sleep Quality Index), sleep reactivity (Ford Insomnia Response to Stress Test), and mental strain (visual analog scale). The main results showed that stress could be differentiated into relevant stressors (encompassing poor performance, uncertainty in relation to training, school, daily hassles, and sleep) and reactions to stress (with sub-categories facilitative and maladaptive). Sleep could be differentiated into sleep benefits (encompassing energy levels and athletic functioning) and sleep quality (with sub-categories satisfactory and inadequate). All athletes identified relevant stressors, and all athletes were aware of the benefits of sleep for athletic functioning. However, athletes formed two distinctive categories based on the interactions between stress and sleep: three exhibited facilitative reactions to stress and good sleep quality, as well as low sleep reactivity, and low mental strain. The remaining participants exhibited maladaptive reactions to stress and poor sleep quality, as well as high sleep reactivity and high mental strain. Conceptualizing sleep quality based on the evaluation of stressors, reactions to stress, degree of mental strain, and the propensity to stress-related sleep disturbance may offer a plausible explanation for why the occurrence of stressors leads to poor sleep quality in some athletes, but not others.

Aiming strategy affects performance-related factors in biathlon standing shooting

This study focused on investigating differences in shooting performance and performance-related factors between two different aiming strategies (HOLD, low radial velocity during the approach 0.4-0.2 seconds before triggering, and TIMING, high radial velocity) in biathlon standing shooting. A total of 23 biathletes fired 8 × 5 standing shots at rest (REST) and 2 × 5 shots during a race simulation (RACE). Shooting performance (hit point distance from the center of the target), aiming point trajectory and postural balance were measured from each shot. Shooting performance was similar both at REST (HOLD 33 ± 5 mm vs TIMING 38 ± 8 mm, P = .111) and in RACE (40 ± 11 mm vs 47 ± 12 mm, P = .194). Better shooting performance was related to smaller distance of the aiming point mean location (REST r = 0.93, P < .001, RACE r = 0.72, P = .018) and higher time spent within ⅔ of the distance of the hit area edge from the center 0.6-0.0 seconds before triggering (REST r=-0.88, P = .001, RACE r=-0.73, P = .016) in HOLD, and to lower aiming point total velocity 0.6-0.0 seconds before triggering (REST r = 0.77, P = .009, RACE r = 0.88, P = .001) and less aiming point movement 0.2-0.0 seconds before triggering (REST r = 0.82, P = .003, RACE r = 0.72, P = .012) in TIMING. Postural balance was related to shooting performance at REST in both groups and in RACE in TIMING. Biathletes using the hold strategy should focus on stabilizing the aiming point before triggering and aiming at the center, whereas biathletes using the timing strategy benefit of decreasing the total velocity during the final approach as well as minimizing the aiming point movement right before triggering.

The Effect of Compression Garments on Performance in Elite Winter Biathletes

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 available upper- and lower-body compression garments (COMP) or a standard winter-biathlon racing suit (CON). In each trial, the athletes roller-skied on a customized treadmill, completing a time trial simulating the skiing duration of a biathlon sprint race, followed by a time-to-exhaustion test designed to elicit exhaustion within ∼60 to 90 seconds. Heart rate, blood lactate concentration, rating of perceived exertion, thermal sensation, and thermal comfort were monitored throughout each trial, while muscle soreness was measured up to 48 hours after each trial.

RESULTS

Pressure exerted by the clothing was significantly higher at all anatomical sites for COMP compared with CON (P ≤ .002). Wearing COMP led to small positive effects on time-trial (d = 0.31) and time-to-exhaustion test (d = 0.31) performances compared with CON, but these differences were not statistically significant (P > .05). No significant differences were found for any physiological (heart rate or blood lactate concentration) or subjective (rating of perceived exertion, thermal sensation, thermal comfort, or muscle soreness) responses between COMP and CON (P > .05).

CONCLUSION

Wearing COMP during maximal cross-country skiing may have small but worthwhile beneficial effects on performance for some individuals. Due to individual variation, athletes are advised to test COMP prior to competition.

Eleven Years' Monitoring of the World's Most Successful Male Biathlete of the Last Decade

PURPOSE

To report the changes in the training characteristics, performance, and heart-rate variability (HRV) of the world's most successful male biathlete of the last decade.

METHOD

During the analyzed 11-year (2009-2019) period, the participant won 7 big crystal globes, corresponding to the winner of the International Biathlon Union World Cup. The training characteristics are reported as yearly volume (in hours) of low-intensity training (LIT), moderate- and high-intensity training, and speed and strength training. Performance was quantified by the number of World Cup top-3 positions per season. HRV was expressed as low- and high-frequency spectral power (in milliseconds squared), root-mean-square difference of successive R-R interval (in milliseconds), and heart rate (in beats per minute).

RESULTS

The training volume increased from 530 to ∼700 hours per year in 2009-2019, with a large polarization in training intensity distribution (ie, LIT 86.3% [2.9%]; moderate-intensity training 3.4% [1.5%]; high-intensity training 4.0% [0.7%]; strength 6.3% [1.6%]). The number of top-3 positions increased from 2 to 24-26 in 2009-2018 but decreased to 6 in 2019. The mean supine values in the root-mean-square difference of successive R-R interval and high-frequency spectral power divided by heart rate increased until 2015, which were stable over 2016-2018 but decreased in 2019. The number of top-3 positions was related to the total (r = .66, P = .02) and LIT (r = .92, P < .001) volume and to several markers of supine parasympathetic activity.

CONCLUSION

The improvement in performance of the participant was mainly determined by the progressive increase in training volume, especially performed at low intensity, and was correlated to parasympathetic activity markers. This case study confirms the effectiveness of the training method, with a large amount of LIT in an elite endurance athlete, and of regular HRV monitoring.

The Annual Periodization of Training Volumes of International-Level Cross-Country Skiers and Biathletes

PURPOSE

To compare the training-volume (TrV) distribution of Russian international-level male biathletes, female biathletes, and cross-country skiers (XC) during an annual cycle.

METHODS

Day-to-day TrVs were recorded and averaged for a 5-year period for male biathletes (n = 6), female biathletes (n = 8), and XC (n = 14) with VO2max values of 77.7 (3.8), 64.6 (1.9), and 79.4 (3.5) mL·min-1·kg-1, respectively.

RESULTS

The volumes of low- and moderate-intensity endurance training and all types of nonspecific endurance and strength training gradually decreased toward the competition period. However, the volumes and proportions of high-intensity endurance training and specific exercises (roller skiing, skiing, and shooting during high-intensity endurance training) increased by the time of the competition period. The total volume of training, volumes of low- and moderate-intensity endurance training, moderate- and high-load strength training (70%-95% 1RM), and power/speed loads did not increase gradually but reached their maximum immediately after a short stage of initial training. All teams employed the "pyramid" model of intensity distribution. Compared with the biathletes, XC demonstrated a larger (P < .01) annual volume of endurance training (~190 h), low-intensity endurance training (~183 h), and strength training (~818 sets). They also engaged in more upper-body and core-strength exercises (~769 sets), and they reached their maximum aerobic TrVs in June, while the biathletes reached theirs in July.

CONCLUSIONS

In recent decades, the traditional model of periodization has been altered. The Russian XC and biathletes had significant differences in TrVs.

Laboratory-Based Factors Predicting Skiing Performance in Female and Male Biathletes

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˙O_2max 56 ± 4 mL·kg⁻¹·min⁻¹) and 14 male (24 ± 4 year, V˙O_2max 66 ± 3 mL·kg⁻¹·min⁻¹) biathletes performed a submaximal incremental test and a maximal time-trial (TT) using treadmill roller-skiing for the assessment of oxygen uptake at a lactate threshold of 4 mmol·L⁻¹ (V˙O_2@4mmol), gross efficiency (GE), aerobic (MR_ae) and anaerobic (MR_an) metabolic rates, peak oxygen consumption (V˙O_2peak), anaerobic capacity and TT performance. Field-based skiing performance was assessed during a BC. The TT and BC skiing performances were significantly correlated in both sexes (r = 0.68–0.69, p < 0.01). V˙O_2peak (31/21%), anaerobic capacity (1/0%), and GE (35/32%) explained 67 and 52% of the variance in BC skiing performance for the females (p < 0.01) and males (p = 0.051), respectively. A second model showed that V˙O_2@4mmol (30/35%), anaerobic capacity (0/0%) and GE (37/13%) explained 67 and 48% of the variance in BC skiing performance for the females (p < 0.01) and males (p = 0.077), respectively. Results of this study suggest that a high V˙O_2@4mmol and GE, but not anaerobic capacity, are important for BC skiing performance, especially for females. In addition, a laboratory-based TT could be useful for regular laboratory testing of biathletes due to its relationship with field-based skiing performance in biathlon.

Biathlon Injury and Illness Surveillance project (BIIS): development of biathlon-specific surveillance forms in English, Russian, French and German

Objective

The aim of this project was to adapt the English, French, German and Russian versions of the International Olympic Committee (IOC) injury and illness surveillance form to be sport-specific for use in biathlon.

Methods

23 medical representatives from 16 of the 55 biathlon federations participated in this project to adapt the form and create disease coding relevant to biathlon. The English version of the IOC injury and illness surveillance form was used as the primary template. Four review rounds were used to develop electronic fillable PDF forms. The changes were then forward translated onto the Russian, French and German forms.

Results

Changes were made to event type to biathlon-specific events. A weekly reporting format was adopted in line with the race week format of World Cup events. Wherever possible, coding replaced free-text format to avoid translation issues. New codes were created to describe the time of injury/illness. A new symptom code was added to reflect the prevalence of respiratory infection: sore throat/cold symptoms. As the number of athletes in a team differs between weeks in the season, an additional question was added to ask for the ‘number of athletes in the team for the week’ and for the season.

Conclusion

This project provides a biathlon-specific injury and illness surveillance form in English, French, German and Russian. This forms the basis for surveillance that will contribute to a greater understanding of the illness and injury rate in elite biathletes and ultimately to enhanced athlete well-being and success in biathlon, and winter sports more generally.

High incidence rate of asthma among elite endurance athletes: a prospective 4-year survey

Objective: The prevalence of asthma among elite endurance athletes is high, but less is known about the incidence of asthma among athletes. The aim of this study was to examine the incidence rate of physician-diagnosed asthma among elite endurance athletes.Method: An annual postal questionnaire was sent to an open prospective cohort of elite endurance athletes between 2011 and 2015. Athletes from Swedish National teams, students at universities with elite sport partnership, and pupils at Swedish National elite sport schools, competing in cross-country skiing, biathlon, ski orienteering, or orienteering were invited (n = 666). Incidence rate of physician-diagnosed asthma was calculated among those without asthma at baseline (n = 449). Risk factors for incident physician-diagnosed asthma were identified using a multivariate logistic regression analysis.Results: Response rate was 88.7% (n = 591) at baseline. The median age of participants was 17 (range 15-36) years at inclusion. The study population included 407 (69%) skiers and 184 (31%) orienteers. The prevalence of asthma at baseline was 23.9% (n = 141). Incidence rate (95% confidence interval [CI]) of physician-diagnosed asthma was 61.2 (45.7-80.3) per 1,000 person-years. Risk factors (odds ratio [OR (95% CI)]) for incident physician-diagnosed asthma were family history of asthma (1.97 [1.04-3.68]), being a skier (3.01 [1.42-7.21]), and wheezing without having a cold (4.15 [1.81-9.26]).Conclusion: The incidence rate of physician-diagnosed asthma is high among Swedish elite endurance athletes.

Physiological Responses to Rifle Carriage During Roller-Skiing in Elite Biathletes

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.O_2max 59.4 ± 7.6 mL.kg^–1.min^–1) performed a submaximal incremental test and a maximal time-trial (TT) using treadmill roller-skiing (gear 3, skating technique) on two occasions separated by at least 48 h. One condition involved carrying the rifle on the back (WR) and the other condition no rifle (NR) and the tests were randomized. Submaximal V.O₂, skiing speed at 4 mmol.L^–1 of blood lactate (speed_@4mmol), gross efficiency (GE), aerobic (MR_ae), and anaerobic (MR_an) metabolic rates, and V.O_2max were determined.

Results: Submaximal V.O₂ (at all intensities) and GE (16.7 ± 0.9 vs. 16.5 ± 1.1%) were higher for WR compared to NR (p < 0.05), while speed_@4mmol was lower (3.1 ± 0.4 vs. 3.3 ± 0.5 m.s^–1, p = 0.040). TT performance was improved (4.6 ± 0.4 vs. 4.3 ± 0.4 m.s^–1, p < 0.001) and MR_an was higher (31.3 ± 8.0 vs. 27.5 ± 6.5 kJ.min^–1, p < 0.01) for NR compared to WR, with no difference in V.O_2max or MR_ae. For skiing WR, TT performance was correlated to speed_@4mmol (r = 0.81, p < 0.001), MR_an (r = 0.65, p < 0.01), V.O_2max (r = 0.51, p < 0.05), and relative muscle (r = 0.67, p < 0.01) and fat (r = −0.67, p < 0.01) masses. Speed_@4mmol together with MR_an explained more than 80% of the variation in TT performance (WR 84%, NR 81%). Despite a higher relative mass of the rifle in females compared with males (5.6 ± 0.4 vs. 5.0 ± 0.4% of body mass, p = 0.012), there were no sex differences associated with rifle carriage measured as absolute or relative differences.

Conclusion: Rifle carriage in biathlon skiing led to significantly higher physiological demands during submaximal exercise and reduced performance during maximal treadmill roller-skiing compared to NR for both sexes. The most important variables for performance in biathlon treadmill skiing seem to be speed_@4mmol combined with MR_an, both of which were lower for WR compared to NR. To improve skiing performance in biathlon, improving speed at 4 mmol.L^–1 of blood lactate and anaerobic energy delivery while carrying the rifle are recommended.

Influence of Altitude on Elite Biathlon Performances

Biathlon is a complex sport subjected to large performance variability. Among the environmental conditions (e.g., temperature, wind, snow conditions) susceptible to influence performance, altitude is likely a detrimental factor for skiing (i.e., due to decreased aerobic capacity) as well as for prone and/or-to a larger extent-standing shooting (i.e., due to altered postural control and increased ventilation) performances. The aim of the present study was therefore to analyze the influence of altitude on elite biathlon performance. The analysis comprised data extracted from the International Biathlon Union (IBU) website and included IBU World Cup, IBU Cup, IBU World Championships, and Olympic Winter Games events over 8 years from season 2009-2010 to 2016-2017. The research included sprint, individual, mass start, and pursuit competitions for both men and women (no relays). The event sites were divided into three different altitude ranges: <700, 700-1400, and >1400 m. Only the Top-30 of each race were recorded for both men and women, separately, and analyzed for skiing speed, prone, and standing shooting performances. The results show a detrimental effect of altitude (i.e., ∼3.0% between <700 and >1400 m) on shooting performance that was similar for men and women but without any statistical difference between prone and standing positions. Due to many other confounding factors not analyzed here (snow quality, course profile), the effect of altitude on skiing speed was unclear. Overall, as expected, elite biathlon performances are altered, even within the range of moderate altitudes of the IBU competitions (<1800 m).

The effects of hypobaric hypoxia on erythropoiesis, maximal oxygen uptake and energy cost of exercise under normoxia in elite biathletes

The aim of the present study was to evaluate the effects of 3 weeks altitude training according to the HiHiLo (live high-base train high-interval train low) procedure as described by Chapman et al. (1998), on erythropoiesis, maximal oxygen uptake and energy cost of exercise under normoxia in elite biathletes. Fifteen male elite biathletes randomly divided into an experimental (H) group (n = 7; age 27.1 ± 4.6 years; maximal oxygen uptake (VO2max) 66.9 ± 3.3 ml·kg(-1)·min(-1); body height (BH) 1.81 ± 0.06 m; body mass (BM) 73.1 ± 5.4kg), and a control (C) group (n = 8; age 23.2 ± 0.9 years; VO2max 68.2 ± 4.1 ml·kg(-1)·min(-1); BH 1.75 ± 0.03 m; BM 63.1 ± 1.5 kg) took part in the study. The H group stayed for 3 weeks at an altitude of 2015 m and performed endurance training on skis four times per week at 3000 m. Additionally, the training protocol included three high-intensity interval sessions at an altitude of 1000 m. The C group followed the same training protocol with skirollers in normoxia at an altitude of 600 m. The HiHiLo protocol applied in our study did not change VO2max or maximal workload (WRmax) significantly during the incremental treadmill test in group H. However, the energy cost for selected submaximal workloads in group H was significantly (p < 0.01) reduced compared to group C (-5.7%, -4.4%, -6% vs. -3.5%, -2.1%, -2.4%). Also a significant (p < 0.001) increase in serum EPO levels during the first two weeks of HiHiLo training at 2015 m was observed, associated with a significant (p < 0.05) increase in hemoglobin mass, number of erythrocytes, hematocrit value and percent of reticulocytes compared with initial values (by 6.4%, 5%, 4.6% and 16,6%, respectively). In group C, changes in these variables were not observed. These positive changes observed in our study led to a conclusion that the HiHiLo training method could improve endurance in normoxia, since most of the biathlon competitions are performed at submaximal intensities. Key pointsThe observed results suggests that the 3-weeks HiHiLo protocol is an effective training means for improving energy cost during submaximal exercise at sea level.The 3-weeks HiHiLo protocol increased the rate of erythropoiesis and improved most haematological variables.However, the positive changes in the athletes haematological variables after the HiHiLo protocol did not contribute to the improvement of VO2max values.