Performance and micro-pacing strategies in sit para-biathlon.

This study investigated micro-pacing strategies during sit para-biathlon. Six elite sit para-biathletes wore a positioning system device during the world-championships in three different competition formats (Sprint, Middle-distance, and Long-distance). Total Skiing Time (TST), penalty-time, shooting-time, and Total Race Time (TRT) were analysed. One-way analyses of variance were used to compare the relative contributions of TST, penalty-time, and shooting-time to TRT across the three race formats. Statistical parametric mapping (SPM) was used to determine the course positions (clusters) where instantaneous skiing speed was significantly associated with TST. The contribution of TST to TRT was lower for the Long-distance (80 ± 6%) compared to the Sprint (86 ± 5%) and Middle-distance (86 ± 3%) races, however this difference was not statistically significant (p > 0.05). The proportional contribution of penalty-time to TRT was significantly greater (p < 0.05) for the Long-distance (13 ± 6%) compared to the Sprint (5 ± 4%) and Middle-distance (4 ± 3%) races. Statistical parametric mapping (SPM) revealed specific clusters where instantaneous skiing speed was significantly associated with TST. For example, over all laps during the Long-distance race, the fastest athlete gained 6.5 s over the slowest athlete in the section with the steepest uphill. Overall, these findings can provide insights into pacing strategies and help para-biathlon coaches and athletes optimise training programmes to improve performance.

Effects of different increments in workload and duration on peak physiological responses during seated upper-body poling.

PURPOSE: To compare the effects of test protocols with different increments in workload and duration on peak oxygen uptake ([Formula: see text]O2peak), and related physiological parameters during seated upper-body poling (UBP). METHODS: Thirteen upper-body trained, male individuals completed four UBP test protocols with increments in workload until volitional exhaustion in a counterbalanced order: 20 W increase/every 30 s, 20 W/60 s, 10 W/30 s and 10 W/60 s. Cardio-respiratory parameters and power output were measured throughout the duration of each test. Peak blood lactate concentration (bLapeak) was measured after each test. RESULTS: The mixed model analysis revealed no overall effect of test protocol on [Formula: see text]O2peak, peak minute ventilation (VEpeak), peak heart rate (HRpeak), bLapeak (all p ≥ 0.350), whereas an overall effect of test protocol was found on peak power output (POpeak) (p = 0.0001), respiratory exchange ratio (RER) (p = 0.024) and test duration (p < 0.001). There was no difference in POpeak between the 20 W/60 s (175 ± 25 W) and 10 W/30 s test (169 ± 27 W; p = 0.092), whereas POpeak was lower in the 10 W/60 s test (152 ± 21 W) and higher in the 20 W/30 s test (189 ± 30 W) compared to the other tests (all p = 0.001). In addition, RER was 9.9% higher in the 20 W/30 s compared to the 10 W/60 s test protocol (p = 0.003). CONCLUSIONS: The UBP test protocols with different increments in workload and duration did not influence [Formula: see text]O2peak, and can therefore be used interchangeably when [Formula: see text]O2peak is the primary outcome. However, POpeak and RER depend upon the test protocol applied and the UBP test protocols can, therefore, not be used interchangeably when the latter is the primary outcome parameter.

Comparison of peak oxygen uptake and exercise efficiency between upper-body poling and arm crank ergometry in trained paraplegic and able-bodied participants.

PURPOSE: To compare peak oxygen uptake (VO2peak) and exercise efficiency between upper-body poling (UBP) and arm crank ergometry (ACE) in able-bodied (AB) and paraplegic participants (PARA). METHODS: Seven PARA and eleven AB upper-body trained participants performed four 5-min submaximal stages, and an incremental test to exhaustion in UBP and ACE. VO2peak was the highest 30-s average during the incremental test. Metabolic rate (joule/second = watt) at fixed power outputs of 40, 60, and 80 W was estimated using linear regression analysis on the original power-output-metabolic-rate data and used to compare exercise efficiency between exercise modes and groups. RESULTS: VO2peak did not significantly differ between UBP and ACE (p = 0.101), although peak power output was 19% lower in UBP (p < 0.001). Metabolic rate at fixed power outputs was 24% higher in UBP compared to ACE (p < 0.001), i.e., exercise efficiency was lower in UBP. PARA had 24% lower VO2peak compared to AB (p = 0.010), although there were no significant differences in peak power output between PARA and AB (p = 0.209). CONCLUSIONS: In upper-body-trained PARA and AB participants, VO2peak did not differ between UBP and ACE, indicating that these two test modes tax the cardiovascular system similarly when the upper body is restricted. As such, the 19% lower peak power output in UBP compared to ACE may be explained by the coinciding lower efficiency.

The effect of the athletes' origin and type of impairment on participation and the likelihood of winning a medal in the Paralympic Games.

OBJECTIVE: This study investigated whether the origin (acquired or congenital) and type of impairment affect the participation and likelihood of winning a medal in different sports at the Paralympic Games. DESIGN: We analyzed competition data and athlete biographies web scraped from the International Paralympic Committee's website (www.Paralympic.org). RESULTS: In some sports, athletes with one origin or type of impairment were overrepresented. E.g., 76% of Para-snowboarders had an acquired impairment. Further, mixed-effects logistic regression analyses showed that the origin of impairment had no effect on the likelihood of winning a medal in most sports. However, athletes with a congenital impairment had a significantly higher likelihood of winning a medal compared to those with an acquired impairment in Para-athletics, Para-alpine skiing, and Para-biathlon (OR: 1.71, p < 0.01, OR: 3.69, p = 0.002, and OR: 3.70, p = 0.016, respectively). Athletes with a given origin-type of impairment combination also may have an advantage or disadvantage in some sports. E.g., athletes with an acquired spinal cord injury win proportionally fewer medals in Para-powerlifting. CONCLUSION: Understanding potential effects of the origin and type of impairment on participation and medaling chances in Paralympic sports can help shape the development of Para-sports, and support talent identification.

Accuracy of the Apple Watch Series 4 and Fitbit Versa for Assessing Energy Expenditure and Heart Rate of Wheelchair Users During Treadmill Wheelchair Propulsion: Cross-sectional Study.

BACKGROUND: The Apple Watch (AW) Series 1 provides energy expenditure (EE) for wheelchair users but was found to be inaccurate with an error of approximately 30%, and the corresponding error for heart rate (HR) provided by the Fitbit Charge 2 was approximately 10% to 20%. Improved accuracy of estimated EE and HR is expected with newer editions of these smart watches (SWs). OBJECTIVE: This study aims to assess the accuracy of the AW Series 4 (wheelchair-specific setting) and the Fitbit Versa (treadmill running mode) for estimating EE and HR during wheelchair propulsion at different intensities. METHODS: Data from 20 manual wheelchair users (male: n=11, female: n=9; body mass: mean 75, SD 19 kg) and 20 people without a disability (male: n=11, female: n=9; body mass: mean 75, SD 11 kg) were included. Three 4-minute wheelchair propulsion stages at increasing speed were performed on 3 separate test days (0.5%, 2.5%, or 5% incline), while EE and HR were collected by criterion devices and the AW or Fitbit. The mean absolute percentage error (MAPE) was used to indicate the absolute agreement between the criterion device and SWs for EE and HR. Additionally, linear mixed model analyses assessed the effect of exercise intensity, sex, and group on the SW error. Interclass correlation coefficients were used to assess relative agreement between criterion devices and SWs. RESULTS: The AW underestimated EE with MAPEs of 29.2% (SD 22%) in wheelchair users and 30% (SD 12%) in people without a disability. The Fitbit overestimated EE with MAPEs of 73.9% (SD 7%) in wheelchair users and 44.7% (SD 38%) in people without a disability. Both SWs underestimated HR. The device error for EE and HR increased with intensity for both SWs (all comparisons: P<.001), and the only significant difference between groups was found for HR in the AW (-5.27 beats/min for wheelchair users; P=.02). There was a significant effect of sex on the estimation error in EE, with worse accuracy for the AW (-0.69 kcal/min; P<.001) and better accuracy for the Fitbit (-2.08 kcal/min; P<.001) in female participants. For HR, sex differences were found only for the AW, with a smaller error in female participants (5.23 beats/min; P=.02). Interclass correlation coefficients showed poor to moderate relative agreement for both SWs apart from 2 stage-incline combinations (AW: 0.12-0.57 for EE and 0.11-0.86 for HR; Fitbit: 0.06-0.85 for EE and 0.03-0.29 for HR). CONCLUSIONS: Neither the AW nor Fitbit were sufficiently accurate for estimating EE or HR during wheelchair propulsion. The AW underestimated EE and the Fitbit overestimated EE, and both SWs underestimated HR. Caution is hence required when using SWs as a tool for training intensity regulation and energy balance or imbalance in wheelchair users.

Peak Age and Performance Trajectories in Para Powerlifters.

OBJECTIVE: This study established the age-related performance trajectories in Para powerlifters, thereby presenting valuable information for athlete development. DESIGN: Data on athlete date of birth, body mass, and weight lifted in competition were analyzed for 2079 athletes between 1994 and 2019. RESULTS: Age-related performance trajectories showed that men and women lift their heaviest weights in competition at 36 and 41 yrs of age, respectively. This correspond to the mean age of competitors in the heaviest bodyweight categories at elite competitions (men 36 yrs, women 43 yrs), who were older than competitors in lighter bodyweight categories. It is possible that para powerlifters "move up" bodyweight categories as they get older and before lifting their heaviest weights in competition. High-performing athletes lifted their heaviest weight in competition 2.6 yrs earlier than lower performing peers, and the best performances in most bodyweight categories were achieved by athletes between 31 and 35 yrs of age. CONCLUSIONS: These results suggest that para powerlifters should reach their peak performance in their early to mid-30s and before age-related changes to neural and hormonal processes impact muscular strength. This information can help coaches and athletes evaluate their strategies for achieving success in para powerlifting.

Test-Retest Reliability of Physiological Variables During Submaximal Seated Upper-Body Poling in Able-Bodied Participants.

Purpose: To investigate the test-retest reliability of physiological variables across four different test days and four different submaximal exercise intensities during seated upper-body poling (UBP). Methods: Thirteen abled-bodied, upper-body trained men (age 29±3years; body mass 84±12kg; height 183±5cm) performed four submaximal 4-min stages of seated UBP on four separate test days. The four submaximal stages were set at individual power outputs corresponding to a rating of perceived exertion of 9, 11, 13, and 15. The absolute reliability for pairwise test-day comparisons of the physiological variables was investigated with the smallest detectable change percentage (%SDC) and the relative reliability with the interclass correlation coefficient (ICC). Results: Absolute and relative reliability across test-day comparisons and submaximal stages were moderate to excellent for all variables investigated (V̇O2 - %SDC range: 5-13%, ICC range: 0.93-0.99; HR - %SDC range: 6-9%, ICC range: 0.91-0.97) other than blood lactate, for which absolute reliability was poor and relative reliability highly variable (%SDC range: 26-69%, ICC range: 0.44-0.92). Furthermore, absolute and relative reliability were consistent across the low-to-moderate exercise intensity spectrum and across test days. Conclusion: Absolute and relative test-retest reliability were acceptable for all investigated physiological variables but blood lactate. The consistent test-retest reliability across the exercise intensity spectrum and across test days indicates that a familiarization period to the specific exercise modality may not be necessary. For generalizability, these findings need to be confirmed in athletes with a disability by future large-scale studies.

Training Distribution During a Paralympic Cycle for a Multiple Swimming Champion With Paraplegia: A Case Report.

PURPOSE: To describe the training volume, intensity distribution, and use of swimming styles during a Paralympic cycle in a multiple swimming champion with paraplegia. METHODS: The female Paralympic swimmer was 23-26 years of age and had a body mass of 60 to 62 kg and a body height of 174 cm. She has a spinal cord injury at the Th6 level, competed in the S5/SB4 Para swimming classes, and uses a wheelchair for mobility. Training time, as well as distance in the different intensity zones and swimming styles, was registered with the "workouts for swim coaches" software throughout a full Paralympic cycle. RESULTS: The Para swimmer performed a total of 388, 524, 471, and 656 annual hours of swimming, corresponding to 1126, 1504, 1463, and 1993 km, in the 2012-13, 2013-14, 2014-15, and 2015-16 seasons, respectively. In addition, she performed 1 to 3 weekly dry-land strength sessions and 4 to 6 weekly dry-land basic skill sessions. She conducted 91% to 94% of the swimming distance in each macrocycle at low intensity, 2% to 4% at moderate intensity, and 3% to 6% at high intensity. She performed 78% to 84% of the swimming distance in each macrocycle in the freestyle swimming technique and the remaining 16% to 22% in the backstroke, breaststroke, and butterfly techniques. CONCLUSION: This case study exemplifies how a female Paralympic swimmer with paraplegia progressed her training in the seasons leading up to the Paralympic Games, reaching an annual training distance of 2000 km, which is similar to that of able-bodied swimmers.

Changes in the Number of Medal Events, Sport Events, and Classes During the Paralympic Games: A Historical Overview.

PURPOSE: To chart how changes in the number of medal events relate to changes in the number of sport events and classes during the Paralympic Games (PG) between 1960 and 2018. METHODS: Web-scraping was used to extract information from the website of the International Paralympic Committee (IPC) on all unique medal events, sport events, and classes per PG, which were then accumulated per sport to descriptively identify and further explore changes. RESULTS: The increased number of medal events during the early Summer Games (SG) (1960-1984: 113-975) and Winter Games (WG) (1976-1994: 55-113) was primarily due to an increased number of classes and sport events. While this suggested an increased sports participation among athletes with disabilities, it made the PG difficult to organize. A decrease in the number of medal events subsequently occurred during the SG (1984-1992: 975-489) and WG (1994-2006: 133-58). This was mainly achieved by reducing the number of sport events in the larger sports. Following this decline phase, the number of medal events and sport events has remained relatively stable for both editions of the PG, though this was achieved through different strategies. The WG employed the time-factor system for all individual sports, which enabled competitions across classes within sport events and thus, award a single gold medal (one medal event) for several classes. The SG have maintained the number of medal events despite a slight increase in classes (112-181). This was due to some sports combining classes in the same event, while others excluded certain classes from certain sport events. CONCLUSIONS: The number of medal events during each PG appear to be closely related to the number of sport events and, partially, to the number of classes. The stability in the number of medal events may indicate that a balance has been achieved, where there currently are enough classes and sport events to ensure fairness, while also maintaining a level of prestigiousness for winning a medal. However, it remains to be seen whether this stability will last or if the continued growth of the PG with more athletes and countries will warrant changes in the number of medal events.

Upper- vs. Lower-Body Exercise Performance in Female and Male Cross-Country Skiers.

Purpose: To investigate the interaction between exercise modality (i.e., upper- and lower-body exercise) and sex in physiological responses and power output (PO) across the entire intensity spectrum (i.e., from low to maximal intensity). Methods: Ten male and 10 female cross-country (XC) skiers performed a stepwise incremental test to exhaustion consisting of 5 min stages with increasing workload employing upper-body poling (UP) and running (RUN) on two separate days. Mixed measures ANOVA were performed to investigate the interactions between exercise modalities (i.e., UP and RUN) and sex in physiological responses and PO across the entire exercise intensity spectrum. Results: The difference between UP and RUN (ΔUP-RUN), was not different in the female compared with the male XC skiers for peak oxygen uptake (18 ± 6 vs. 18 ± 6 mL·kg-1·min-1, p = 0.843) and peak PO (84 ± 18 vs. 91 ± 22 W, p = 0.207). At most given blood lactate and rating of perceived exertion values, ΔUP-RUN was larger in the male compared with the female skiers for oxygen uptake and PO, but these differences disappeared when the responses were expressed as % of the modality-specific peak. Conclusion: Modality-differences (i.e., ΔUP-RUN) in peak physiological responses and PO did not differ between the female and male XC skiers. This indicates that increased focus on upper-body strength and endurance training in female skiers in recent years may have closed the gap between upper- and lower-body endurance capacity compared with male XC skiers. In addition, no sex-related considerations need to be made when using relative physiological responses for intensity regulation within a specific exercise modality.

A Reappraisal of Ventilatory Thresholds in Wheelchair Athletes With a Spinal Cord Injury: Do They Really Exist?

The ventilatory threshold (VT) separates low- from moderate-intensity exercise, the respiratory compensation point (RCP) moderate- from high-intensity exercise. Both concepts assume breakpoints in respiratory data. However, the objective determination of the VT and RCP using breakpoint models during upper-body modality exercise in wheelchair athletes with spinal cord injury (SCI) has received little attention. Therefore, the aim of this study was to compare the fit of breakpoint models (i.e., two linear regression lines) with continuous no-breakpoint models (i.e., exponential curve/second-order polynomial) to respiratory data obtained during a graded wheelchair exercise test to exhaustion. These fits were compared employing adjusted R2, and blocked bootstrapping was used to derive estimates of a median and 95% confidence intervals (CI). V̇O2-V̇CO2 and V̇E/V̇O2-time data were assessed for the determination of the VT, and V̇CO2-V̇E and V̇E/V̇CO2-time data for the determination of the RCP. Data of 9 wheelchair athletes with tetraplegia and 8 with paraplegia were evaluated. On an overall group-level, there was an overlap in the adjusted R2 median ± 95% CI between the breakpoint and the no-breakpoint models for determining the VT (V̇O2-V̇CO2: 0.991 ± 0.003 vs. 0.990 ± 0.003; V̇E/V̇O2-time: 0.792 ± 0.101 vs. 0.782 ± 0.104, respectively) and RCP (V̇E-V̇CO2: 0.984 ± 0.004 vs. 0.984 ± 0.004; V̇E/V̇CO2-time: 0.729 ± 0.064 vs. 0.691 ± 0.063, respectively), indicating similar model fit. We offer two lines of reasoning: (1) breakpoints in these respiratory data exist but are too subtle to result in a significant difference in adjusted R2 between the investigated breakpoint and no-breakpoint models; (2) breakpoints do not exist, as has been argued previously.

Case Report: Adjusting Seat and Backrest Angle Improves Performance in an Elite Paralympic Rower.

Paralympic rowers with functional impairments of the legs and trunk rely on appropriate seat configurations for performance. We compared performance, physiology, and biomechanics of an elite Paralympic rower competing in the PR1 class during ergometer rowing in a seat with three different seat and backrest inclination configurations. Unlike able-bodied rowers, PR1 rowers are required to use a seat with a backrest. For this study, we examined the following seat/backrest configurations: conA: 7.5°/25°, conB: 0°/25°, and conC: 0°/5° (usually used by the participant). All data was collected on a single day, i.e., in each configuration, one 4-min submaximal (100 W) and one maximal (all-out) stage was performed. The rowing ergometer provided the average power and (virtual) distance of each stage, while motion capture provided kinematic data, a load cell measured the force exerted on the ergometer chain, and an ergospirometer measured oxygen uptake ( V ˙ O 2 ). Where appropriate, a Friedman's test with post-hoc comparisons performed with Wilcoxon signed-ranked tests identified differences between the configurations. Despite similar distances covered during the submaximal intensity (conA: 793, conB: 793, conC: 787 m), the peak force was lower in conC (conA: 509, conB: 458, conC: 312 N) while the stroke rate (conA: 27 conB: 31, conC: 49 strokes·min-1) and V ˙ O 2 (conA: 34.4, conB: 35.4, conC: 39.6 mL·kg-1·min-1) were higher. During the maximal stage, the virtual distances were 7-9% longer in conA and conB, with higher peak forces (conA: 934 m, 408 N, conB: 918 m, 418 N, conC: 856 m, 331 N), and lower stroke rates (conA: 51, conB: 54, conC: 56 strokes·min-1), though there was no difference in V ˙ O 2 peak (~47 ml-1·kg-1·min-1). At both intensities, trunk range of motion was significantly larger in configurations conA and conB. Although fatigue may have accumulated during the test day, this study showed that a more inclined seat and backrest during ergometer rowing improved the performance of a successful Paralympic PR1 rower. The considerable increase in ergometer rowing performance in one of the top Paralympic rowers in the world is astonishing and highlights the importance of designing equipment that can be adjusted to match the individual needs of Paralympic athletes.

Changes in physical activity and basic psychological needs related to mental health among people with physical disability during the COVID-19 pandemic in Norway.

BACKGROUND: People with a physical disability are more inactive than the general population. Due to the positive effects of physical activity (PA) on physical and mental health, maintaining a physically active lifestyle is important especially during challenging periods of life. OBJECTIVE: Explore whether people with a physical disability experienced changes in PA, health status, and psychological need satisfaction (autonomy, competence and relatedness) during the first wave of the COVID-19 pandemic in Norway. Further, explore whether changes in psychological need satisfaction were associated with changes in PA level and mental health. METHODS: Cross-sectional retrospective study using an online self-reported questionnaire after the first wave during the COVID-19 pandemic. RESULTS: Of the 298 participants with physical disabilities (AgeM = 49yr; 62% females; 66% using mobility aids), 66% reported decreased PA compared to the same period in the previous year, 45% reported declined health status due to increased pain and reduced physical functioning. Regarding psychological need satisfaction, it was primarily the change in need for autonomy and competence for PA that were associated with change in PA and mental health. CONCLUSIONS: Most of the participants indicated decreased PA and about half decreased Health status during the COVID-19 pandemic. Further, the results indicated that it is important to nurture the basic psychological needs of autonomy and competence for PA when aiming to maintain or increase PA levels and mental health for this population living under restrictions of a pandemic.

Comparison of Peak Oxygen Uptake Between Upper-Body Exercise Modes: A Systematic Literature Review and Meta-Analysis.

Purpose: To compare peak oxygen uptake (VO2peak) between the asynchronous arm crank ergometry (ACE), and synchronous wheelchair ergometry (WERG), wheelchair treadmill (WTR), and upper-body poling (UBP) mode. Methods: PubMed, Scopus, CINAHL, and SPORTDiscus™ were systematically searched, and identified studies screened based on title, abstract, and thereafter full-text. Studies comparing VO2peak between ≥2 of the modes were included. A meta-analysis was performed by pooling the differences in VO2peak between upper-body exercise modes. The quality of the included studies was assessed and the level of evidence (LoE) established for each mode comparison. Meta-regression analyses investigated the effect of total body mass and participant-related characteristics (% of able-bodied participants, % of participants with tetraplegia and % of participants who are wheelchair athletes) on differences in VO2peak between modes. Results: Of the 19 studies included in this review, 14 studies investigated the difference in absolute and body-mass normalized VO2peak between ACE and WERG, and 5 studies examined the differences between ACE and WTR. No significant difference in absolute or body-mass normalized VO2peak was found between ACE and WERG (overall effect ±95% CI: 0.01 ± 0.06 L·min-1 and 0.06 ± 1.2 ml·kg-1·min-1, both p > 0.75; LoE: strong). No significant difference in absolute or body-mass normalized VO2peak was found between ACE and WTR (overall effect ±95% CI: -0.10 ± 0.18 L·min-1 and -1.8 ± 2.5 ml·kg-1·min-1, both p > 0.14; LoE: moderate). Absolute and/or body-mass normalized VO2peak did not differ between WERG and WTR in one study with 13 participants (LoE: limited) and between ACE and UBP in one study with 18 participants (LoE: moderate). In the meta-regression analyses, there was no significant effect of the investigated factors on differences in VO2peak. Conclusions: The differences between the asynchronous ACE and synchronous WERG propulsion, including possible differences in trunk involvement, do not seem to influence VO2peak. Therefore, ACE and WERG can be used interchangeably to test VO2peak. Possible differences in VO2peak in all other mode comparisons remain unclear due to the wide CIs and limited to moderate LoE.

Development of a Framework for the Investigation of Speed, Power, and Kinematic Patterns in Para Cross-Country Sit-Skiing: A Case Study of an LW12 Athlete.

Objective: To develop a framework for the investigation of speed, power, and kinematic patterns across varying terrain in cross-country (XC) sit-skiing, and to test this framework in a XC sit-skier of the LW12 class during high- (HIT) and low-intensity (LIT) endurance training. Methods: One XC sit-skiing athlete of the LW12 class with a single above-the-knee amputation was equipped with a GNSS enabled sports watch with integrated barometry and heart rate monitoring (peak heart rate: 195 beats·min-1), and an inertial measurement unit. After a warm-up, he performed two 20-m maximal speed tests on a flat and an uphill section to determine maximal speed and power, followed by skiing 5.75 km at both LIT and HIT in varying terrain. Results: 51, 28, and 21% of the time during HIT and 53, 28, and 19% of the time during LIT were spent in uphill, flat and downhill terrain, respectively. Maximal speed in the uphill and flat section was 4.0 and 6.2 m·s-1, respectively, and the corresponding maximal power output 342 and 252 W. The % of maximal speed did not differ between the uphill and the flat section (HIT: 66 vs. 67%, LIT: 47 vs. 50%), whereas the % of maximal power output was lower in the uphill than flat section (HIT: 65 and 80%, LIT: 46 and 58%). Still, the absolute power output was slightly higher in the uphill than the flat section (HIT: 222 vs. 201 W, LIT: 156 vs. 145 W). Furthermore, cycle rate was significantly higher during HIT than LIT (60-61 vs. 45-55 cycles·min-1, across all terrains, all p < 0.03), while cycle length was longer in the uphill terrain (3.0 vs. 2.6 m, p < 0.001). Furthermore, the % of peak heart rate was significantly higher in HIT than LIT (90 vs. 78, 85 vs. 67, and 88 vs. 66%, respectively, in the uphill, flat and downhill terrain, all p < 0.001). Conclusions: Here, we present a new integrative framework for future investigations of performance, technical and physical demands in XC sit-skiing. In this case study, the increase in speed from LIT to HIT was due to increases in cycle rate in all terrains, while cycle length was less affected. Although the absolute power output was slightly higher in the uphill compared to the flat section both for HIT and LIT, the athlete worked closer to his maximum power output in the flat section.

Peak oxygen uptake in Paralympic sitting sports: A systematic literature review, meta- and pooled-data analysis.

BACKGROUND: Peak oxygen uptake (VO2peak) in Paralympic sitting sports athletes represents their maximal ability to deliver energy aerobically in an upper-body mode, with values being influenced by sex, disability-related physiological limitations, sport-specific demands, training status and how they are tested. OBJECTIVES: To identify VO2peak values in Paralympic sitting sports, examine between-sports differences and within-sports variations in VO2peak and determine the influence of sex, age, body-mass, disability and test-mode on VO2peak. DESIGN: Systematic literature review and meta-analysis. DATA SOURCES: PubMed, CINAHL, SPORTDiscusTM and EMBASE were systematically searched in October 2016 using relevant medical subject headings, keywords and a Boolean. ELIGIBILITY CRITERIA: Studies that assessed VO2peak values in sitting sports athletes with a disability in a laboratory setting were included. DATA SYNTHESIS: Data was extracted and pooled in the different sports disciplines, weighted by the Dersimonian and Laird random effects approach. Quality of the included studies was assessed with a modified version of the Downs and Black checklist by two independent reviewers. Meta-regression and pooled-data multiple regression analyses were performed to assess the influence of sex, age, body-mass, disability, test mode and study quality on VO2peak. RESULTS: Of 6542 retrieved articles, 57 studies reporting VO2peak values in 14 different sitting sports were included in this review. VO2peak values from 771 athletes were used in the data analysis, of which 30% participated in wheelchair basketball, 27% in wheelchair racing, 15% in wheelchair rugby and the remaining 28% in the 11 other disciplines. Fifty-six percent of the athletes had a spinal cord injury and 87% were men. Sports-discipline-averaged VO2peak values ranged from 2.9 L∙min-1 and 45.6 mL∙kg-1∙min-1 in Nordic sit skiing to 1.4 L∙min-1 and 17.3 mL∙kg-1∙min-1 in shooting and 1.3 L∙min-1 and 18.9 mL∙kg-1∙min-1 in wheelchair rugby. Large within-sports variation was found in sports with few included studies and corresponding low sample sizes. The meta-regression and pooled-data multiple regression analyses showed that being a man, having an amputation, not being tetraplegic, testing in a wheelchair ergometer and treadmill mode, were found to be favorable for high absolute and body-mass normalized VO2peak values. Furthermore, high body mass was favourable for high absolute VO2peak values and low body mass for high body-mass normalized VO2peak values. CONCLUSION: The highest VO2peak values were found in Nordic sit skiing, an endurance sport with continuously high physical efforts, and the lowest values in shooting, a sport with low levels of displacement, and in wheelchair rugby where mainly athletes with tetraplegia compete. However, VO2peak values need to be interpreted carefully in sports-disciplines with few included studies and large within-sports variation. Future studies should include detailed information on training status, sex, age, test mode, as well as the type and extent of disability in order to more precisely evaluate the effect of these factors on VO2peak.

Examination of gas exchange and blood lactate thresholds in Paralympic athletes during upper-body poling.

OBJECTIVES: The primary aim was to compare physiological and perceptual outcome parameters identified at common gas exchange and blood lactate (BLa) thresholds in Paralympic athletes while upper-body poling. The secondary aim was to compare the fit of the breakpoint models used to identify thresholds in the gas exchange thresholds data versus continuous linear and curvilinear (no-breakpoint) models. METHODS: Fifteen elite Para ice hockey players performed seven to eight 5-min stages at increasing workload until exhaustion during upper-body poling. Two regression lines were fitted to the oxygen uptake (VO2)-carbon dioxide (VCO2) and minute ventilation (VE)/VO2 data to determine the ventilatory threshold (VT), and to the VCO2-VE and VE/VCO2 data to determine the respiratory compensation threshold (RCT). The first lactate threshold (LT1) was determined by the first rise in BLa (+0.4mmol·L-1 and +1.0mmol·L-1) and a breakpoint in the log-log transformed VO2-BLa data, and the second lactate threshold (LT2) by a fixed rise in BLa above 4mmol·L-1 and by employing the modified Dmax method. Paired-samples t-tests were used to compare the outcome parameters within and between the different threshold methods. The fit of the two regression lines (breakpoint model) used to identify thresholds in the gas exchange data was compared to that of a single regression line, an exponential and a 3rd order polynomial curve (no-breakpoint models) by Akaike weights. RESULTS: All outcome parameters identified with the VT (i.e., breakpoints in the VO2-VCO2 or VE/VO2 data) were significantly higher than the ones identified with a fixed rise in BLa (+0.4 or +1.0mmol·L-1) at the LT1 (e.g. BLa: 5.1±2.2 or 4.9±1.8 vs 1.9±0.6 or 2.3±0.5mmol·L-1,p<0.001), but were not significantly different from the log-log transformed VO2-BLa data (4.3±1.6mmol·L-1,p>0.06). The outcome parameters identified with breakpoints in the VCO2-VE data to determine the RCT (e.g. BLa: 5.5±1.4mmol·L-1) were not different from the ones identified with the modified Dmax method at the LT2 (5.5±1.1mmol·L-1) (all p>0.53), but were higher compared to parameters identified with VE/VCO2 method (4.9±1.5mmol·L-1) and a fixed BLa value of 4mmol·L-1 (all p<0.03). Although we were able to determine the VT and RCT via different gas exchange threshold methods with good fit in all 15 participants (mean R2>0.931), the continuous no-breakpoint models had the highest probability (>68%) of being the best models for the VO2-VCO2 and the VCO2-VE data. CONCLUSIONS: In Paralympic athletes who exercise in the upper-body poling mode, the outcome parameters identified at the VT and the ones identified with fixed methods at the LT1 showed large differences, demonstrating that these cannot be used interchangeably to estimate the aerobic threshold. In addition, the close location of the VT, RCT and LT2 does not allow us to distinguish the aerobic and anaerobic threshold, indicating the presence of only one threshold in athletes with a disability exercising in an upper-body mode. Furthermore, the better fit of continuous no-breakpoint models indicates no presence of clear breakpoints in the gas exchange data for most participants. This makes us question if breakpoints in the gas exchange data really exist in an upper-body exercise mode in athletes with disabilities.

Laboratory Determinants of Repeated-Sprint and Sport-Specific-Technique Ability in World-Class Ice Sledge Hockey Players.

PURPOSE: To investigate on-ice repeated-sprint and sports-specific-technique abilities and the relationships to aerobic and anaerobic off-ice capacities in world-class ice sledge hockey players. METHODS: Twelve Norwegian national team players performed 8 repeated maximal 30-m sprints and a sports-specific-technique test while upper-body poling on ice, followed by 4 maximal upper-body strength tests and 8-s peak power and 3-min peak aerobic-capacity (VO2peak) tests while ergometer poling. RESULTS: The fastest 30-m sprint time was 6.5 ± 0.4 s, the fastest initial 10-m split-time 2.9 ± 0.2 s, and the corresponding power output 212 ± 37 W. Average 30-m time during the 8 repeated sprints was 6.7 ± 0.4 s, and the sprint-time decrement was 4.3% ± 1.8%. Time to execute the sport-specific-technique test was 25.6 ± 2.7 s. Averaged 1-repetition-maximum strength of the 4 exercises correlated with the fastest 30-m sprint time (r = -.77), the fastest initial 10-m split time (r = -.72), the corresponding power output (r = .67), and the average 30-m sprint time (r = -.84) (all P < .05). Peak power of the 8-s ergometer sprint test correlated with the highest initial 10-m power (r = .83, P < .01) and the average 30-m sprint time (r = -.68, P < .05). Average 3-min ergometer power (r = -.86, P < .01) and VO2peak (r = -.67, P < .05) correlated with the sprint-time decrement. All off-ice variables except VO2peak correlated with technique-test time (r = -.58 to .73, all P < .05). CONCLUSION: Maximal strength and power are associated with the ability to sprint fast and rapid execution of a technically complex test, whereas mode-specific endurance capacity is particularly important for maintenance of sprint ability in ice sledge hockey.