Mid Sweden University

Introduction: Biathlon combines cross country skiing and rifle marksmanship, and the athletes need to carry the rifle (mass >3.5 kg) on their back during skiing. Previous research in laboratory settings have shown that physiological variables, i.e. heart rate (HR), oxygen uptake (VO2), ventilation (VE), breathing frequency (BF), respiratory exchange ratio (RER) and blood lactate concentration (BLa) increases when roller-skiing with rifle (WR) at submaximal workloads compared to roller-skiing without rifle (NR) (1, 2). Roller-skiing performance is also shown to decrease for WR compared to NR during laboratory testing (1). Purpose: The aim was to investigate the effect of rifle carriage on performance and physiological variables during a simulated biathlon roller-skiing sprint in the field.Methods: 20 well-trained tier 3 (3) biathletes (10 women, 10 men; age 22±3 years) completed two biathlon roller-skiing sprints (women 3×2km; men 3×2.5km) in the field, one WR and one NR in a randomized order, separated by 30 minutes of active rest. After each lap, the athlete stopped for 30–45 s (normal shooting time) for measurement of BLa and rating of perceived exertion (RPE, 6–20). Respiratory variables and HR were measured throughout the sprints. A two-way repeated measurements ANOVA (two conditions (WR/NR) × three laps) was used to compare performance and physiological variables between conditions. During the stops, WR and NR was compared using paired samples t-test. Wilcoxon Signed Rank test was used if data was non-normally distributed. Data are presented as mean±SD, except for RPE (presented as median (IQR)).Results: Mean roller-skiing speed for the race was 0.20 m/s slower for WR compared to NR (5.5±0.5 vs. 5.7±0.5 m/s, p<0.001). The time loss during WR was 13.5±14.6, 12.2±8.7 and 16.9±9.6 s for laps 1, 2, and 3, respectively. No difference between WR and NR in mean HR, O2, VE, BF, RER or BLa was found for any of the skiing laps (all p>0.05). However, RPE, mean VO2, VE and BF during the second stop (simulating standing shooting) was higher for WR compared to NR (RPE 18 (1) vs 17 (1), p = 0.008; VO2 40±5 vs 37±4 ml/kg/min, p=0.006; VE 99±23 vs 92±18 L/min, p=0.031; BF 52±6 vs. 48±4 breaths/min, p=0.005) with no difference in the duration of the stop (p>0.05). Conclusion: Unlike previous laboratory studies, this field-based study demonstrates that respiratory variables, HR and BLa were similar for WR and NR during roller-skiing, despite the higher skiing speed for NR during all the three laps. However, respiratory variables and RPE were higher during the second stop for WR, which may impact shooting performance. To replicate competition demands, biathletes are advised to carry their rifle during high-intensity training sessions that include shooting.

1. Jonsson Kårström et. al (2019) doi: 10.3389/fphys.2019.015192. Stöggl et. al (2015) doi: 10.1249/mss.00000000000004383. McKay et. al (2022) doi: 10.1123/ijspp.2021-0451

Purpose To investigate the effect of exercise intensity on standing shooting performance and related technical variables in elite biathletes performing roller skiing and live shooting outdoors.

Methods Nineteen male biathletes performed two 5-shot series in the following order of exercise intensity: rest, low (%heart rate max 73 ± 4; blood lactate 1.5 ± 0.3 mmol·L-1), moderate (84 ± 3; 2.4 ± 0.6), ‘race-pace’ (90 ± 2; 4.5 ± 0.8), and ‘final-lap’ (i.e., near-maximal effort: 93 ± 3; 8.7 ± 1.4). Except for rest, each shooting series was preceded by 1 km roller ski skating on a competition track. Rifle movements and triggering were determined from marker-based motion capture and accelerometer data. The primary variables were shooting outcome (hit/miss) and distance from center (dC), determined from an electronic target, and barrel velocity. Mediation analyses for shooting outcome and dC were conducted with barrel velocity (mean over last 0.25 s before triggering) as mediator and intensity as predictor.

Results Exercise intensity increased the likelihood of miss at ‘race’ (odds ratio (OR) 2.2, 95% CI 1.0-4.7) and ‘final-lap’ (OR 2.8, 95% CI 1.4-5.8) intensities compared to rest, with no meaningful differences between rest, low, and moderate intensities. Further, intensity affected dC (~32 ± 15 mm at rest, low, and moderate, 36 ± 20 mm at ‘race’, and 40 ± 23 mm at ‘final-lap’; p < 0.001). Barrel velocity was a partial mediator of both shooting outcome and dC, explaining some, but not all, of the effect of intensity.

Conclusions Exercise intensity seems to have a clear negative effect on standing shooting performance in biathlon, which is partially explained by an increase in barrel velocity. Deteriorating effects were mainly seen at the two highest (race-like) intensities. Accordingly, for specificity reasons, more shooting practice should perhaps be performed at higher, competition-like exercise intensities than what is currently the norm.

Purpose: This study introduces two-dimensional (2D) Kernel Density Estimation (KDE) plots as a novel tool for visualising Training Intensity Distribution (TID) in biathlon. The goal was to assess how KDE plots, alongside traditional training metrics, might provide a more detailed understanding of heart rate (HR) intensity patterns, aiding in the evaluation of training quality and compliance.

Methods: Fifteen elite-level youth biathletes from two national academy programmes were monitored over 5–6 weeks using HR monitors. Training sessions were measured via time-in-zone (TIZ) within a five-zone HR model with any time accumulated below the threshold for Zone 1, considered Zone 0. Sessions were dichotomised into those planned as low-intensity training (LIT) or those planned with high-intensity training (HIT). KDE analyses were conducted in MATLAB (Version R2020b) using the “ksdensity” function to create 2D KDE plots that visualise HR intensity accumulation across each programme, session type (e.g., Low-intensity training: LIT; High-intensity training: HIT), and individual athlete responses. Traditional histogram plots and grouped bar charts were also used for comparison.

Results: For LIT sessions, athletes performed less time in Zone 1 than planned, while performed time exceeded planned time in Zone 2. For HIT sessions, performed time in Zone 5 was lower than planned. All sessions contained unplanned time in Zone 0. The 2D KDE plots provided a continuous and detailed representation of HR intensity accumulation throughout training sessions, revealing patterns and intensity fluctuations that complement traditional TIZ analyses.

Conclusions: 2D KDE plots might serve as a valuable complementary tool for assessing TID in biathlon, offering a more nuanced and continuous view of HR intensity. By identifying discrepancies between planned and performed training intensity, coaches can refine strategies and provide individualised feedback. Incorporating KDE plots into training monitoring could improve training alignment, helping reduce overtraining or undertraining risks and optimising athlete development.

This study aimed to investigate how different legs as well as cross-country skiing and shooting performances, associate to final rankings in biathlon relay competitions for both women and men. Data including rank, finish/leg time (LT), course (CT), range (RT) and penalty (PT) times, as well as number of shots (NS) and penalty loops (NPL), were collected from the International Biathlon Union’s database over two seasons, comprising 12 competitions for all teams ranked 1–20. Teams were categorized as G3 (rank 1–3), G10 (rank 4–10) and G20 (rank 11–20). Kruskal-Wallis’ test was used to compare the variables between the groups in total for an entire relay competition, and for each leg. For women, LT was longer for G20 across all four legs due to longer CT, and for G10 during legs 2 and 4 due to longer RT compared to G3 (p < 0.05). For men, LT was longer for G20 during all legs due to longer CT and RT (legs 2–4), and for G10 during legs 3 and 4 due to longer CT compared to G3 (p < 0.05). The present results suggest therefore that the shooting performance for women (especially shorter RT) during legs 2 and 4, and skiing performance for men during legs 3 and 4, are most decisive for final performance during a biathlon relay.

This study investigated stability of hold and postural control in a static holding task and a biathlon standing shooting task, and shooting performance, examining the associations between these tasks and potential differences between biathletes employing a hold-based (HBS) or timing-based (TBS) aiming strategy. Twenty-two biathletes completed a static holding test in the standing shooting posture (Holding) and a biathlon standing shooting test (Shooting) using dry shots. Postural control was evaluated using force platforms, and stability of hold was assessed using a Vicon motion capture system (Holding) and a Noptel training device (Shooting). Of the stability of hold measures, links between the tasks were observed in aiming point vertical standard deviation (R = 0.78) and vertical mean velocity (R = 0.74) in HBS and in vertical mean velocity (R = 0.62) in TBS (all P < 0.05). Regardless of aiming strategy, most postural control measures in Holding correlated with their counterparts in Shooting (R = 0.48 to 0.94 and P < 0.05) and shooting performance (hit point distance from the centre of the target) correlated with stability of hold measured during Holding (R = 0.74 and P < 0.001). Among the postural control measures, shooting performance was only clearly linked to front leg postural control measured during Holding in TBS (R = 0.87 and P < 0.003). These findings suggest that static holding ability and postural control are important in biathlon standing shooting regardless of aiming strategy but aiming dynamics during Holding align more closely with the practices of HBS during their shooting.

Aim: To retrospectively describe the annual training characteristics of elite biathletes across different age groups over 2 decades. Methods: Self-documented training-diary data from 18 elite biathletes (tier 4/5, 7 ♀, 11 ♂) between 1994 and 2014 were included in the study and classified by age group (junior: 16–18 y, U23: 19–23 y, senior: >23 y). Linear mixed models were used to analyze the effect of age group on training characteristics (intensity, distance, time, and modality shooting training) for each sex. Results: Male biathletes increased their total training volume (TV) by 34% across age groups, while female biathletes did not show increasing TV with age. Endurance TV increased from junior to senior level by 35% and 23% in both men and women. The proportional distribution of low-intensity training, moderate-intensity training,, and high-intensity training was significantly different for both sexes between age groups. Senior male biathletes shot 4% and 15% more annual shots than Under-23s and juniors due to greater number of technical and in-competition shots, while females only increased in-competition shots at senior level. Conclusion: This study provides further insights into the biathlon training puzzle, suggesting sex-specific differences in training strategies from junior to senior level. Our data may emphasize the importance of increasing endurance TV from junior to senior level by increasing the proportion of low-intensity training, with a reduction in moderate-intensity training and maintenance of high-intensity training when transitioning between age groups. Increasing the number of technical shots, as well as in-competition shots, while maintaining precision-shooting volumes may also be important for biathletes’ long-term development.

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 an intervention group (with 3 hr of neurofeedback training). FMT increased from baseline during the neurofeedback training sessions (p <= .05). However, there were no Group x Pre-post training (test) interactions for FMT or shooting performance (p > .05). There was a small Group x Test effect for attentional focus (p = .07, eta 2p = .12), indicating a potential benefit of neurofeedback training. Superior shooters were more proficient at increasing FMT during neurofeedback training, but this did not translate to greater improvements in shooting performance. Our findings suggest that the effects of neurofeedback training are transient and do not necessarily benefit performance.

Purpose To examine the micro-pacing (within-lap) strategies during biathlon skiing with and without the biathlon rifle. Methods Twenty biathletes (7 women, 13 men) performed two crosscountry skiing time-trials on a ≈2300 m course, once with and once without the biathlon rifle. During time-trials, biathletes wore a sensor that recorded position, distance and skiing-speed. A trajectory correction and statistical parametric mapping procedure determined the course positions (clusters) where instantaneous skiing-speed was significantly related to time-trial performance. The time differences between the fastest and slowest skier in these clusters were calculated. Results The fastest biathletes skied with greater instantaneous speeds in specific clusters, which included both uphill and downhill sections. The clusters represented time gains for the fastest skier over the slowest skier of between 16.1 and 25.8 s for the women and between 18.9 and 21.9 s for the men. The largest time gains between the fastest and slowest biathletes were observed in a downhill section that was preceded by a 180° turn, where time gains were between 2.9 and 4.1 s in clusters of between just 12 to 62 m. In biathlon skiing with-rifle, there were more clusters that were not present during without-rifle. When skiing with-rifle, there were additional clusters in the uphill sections that represented time gains of 5.2 s and 2.3 s for the women and men, respectively. Conclusions Statistical parametric mapping can be used in biathlon to provide pacing and performance feedback to athletes and coaches.