Short Multicomponent Group Exercise Intervention Promotes Long-Term Physical Activity Habits among Community-Dwelling Older Adults during COVID-19 Restrictions: A Cohort Study.

This study investigated whether strength, balance, body mass index, falls self-efficacy, activity levels, self-rated health, and participation in a multicomponent exercise intervention could predict physical activity levels after 5 months of self-quarantine due to the COVID-19 pandemic. This study included baseline data of 200 community-dwelling older adults (79% women, 21% men) with a mean age of 72 years who participated in a randomized controlled trial investigating a multicomponent exercise program, with 7-month follow-up survey data of their physical activity levels. The results showed significant associations with the activity levels at the 7-month follow-up. The activity levels (odds ratio (OR): 2.83, 95% CI: 1.20-6.71), the self-rated health score (2.80, 1.42-5.53), and being allocated to a specific multicomponent group-based exercise program (2.04, 1.04-4.00) showed a significant association with the activity habits at the 7-month follow-up. As this study suggests, besides the physical activity levels and the self-rated health score, participation in a high challenge multicomponent exercise program was significantly associated with physical activity levels at the 7-month follow-up. This study indicates that a relatively short multicomponent group exercise program (6-9 weeks) can motivate individuals to sustain their own training and activity levels even several months after the program has been paused or terminated. Identifying older adults' physical activity levels and self-rated health scores and prescribing multicomponent group-based exercise programs to promote sustained physical activity habits may be a successful alternative to provide for older adults in the future.

High Challenge Exercise and Learning Safe Landing Strategies among Community-Dwelling Older Adults: A Randomized Controlled Trial.

There is limited research on optimal exercise programs that effectively decrease falls and fall-related injuries in older populations. This randomized controlled trial (RCT) aimed to explore the effects of a 12-week Judo4Balance program on falling techniques, physical and psychological functions, health status, and physical activity levels among 200 community-dwelling older adults (79% women and 21% men) with a mean age of 72 years. The 200 participants were randomly allocated for the Judo4Balce program (n = 100) or control group (n = 100). The RCT intervention started in mid-January 2020 and was abruptly interrupted because of the COVID-19 pandemic. A restart of the RCT was initiated in September 2021, and the 12-week intervention was offered to two groups. This study reports the results from three points of assessment: baseline, 20-month follow-up, and 12-week postintervention. At 20 months follow-up, the control group had significantly decreased physical activity levels (summer p = 0.002 and winter p = 0.003); similar changes were not seen in the exercise group. In the exercise group, learning falling techniques in 6−9 weeks led to sustained fall competence at 20 months follow-up. Further, significant improvements in physical function (exercise group p = 0.009 and control group p < 0.001) and learning falling techniques (p < 0.001 for both groups) were noted in both groups after the 12-week intervention. This effective, supervised, group-based, high-challenge multicomponent exercise program needs to be further evaluated for possible impact on falls and fall-related injuries.

A 10-week judo-based exercise programme improves physical functions such as balance, strength and falling techniques in working age adults.

BACKGROUND: Falls and fall-related injuries are major threats not only for older adults but also for younger age groups such as working-age adults. It has been shown that it is possible to reduce the risk of falls and fall-related injuries, to some extent. However, interventions aiming at reducing both the risk of falls and mitigating fall-related injuries through teaching safe falling techniques are still sparsely investigated. The aim with this study was to investigate the effect of a 10-week workplace-based judo inspired exercise programme (Judo4Balance). The measures in the study include physical functions, fall-related self-efficacy and safe falling techniques. METHODS: A total of 142 working-age adults participated in this non-randomised controlled study. The participants were allocated to the Judo4Balance group (n = 79), or to a waiting list control group (n = 63). The mean age was 47 years (18-68). The recruitment period was from May 2018 to October 2019. A total of 128 participants were included in the analysis. Logistic Regression models were used to analyse the outcomes: physical function, balance and fall-related self-efficacy as well as falling techniques (backwards and forwards). RESULTS: At the 10-week follow-up, the results displayed significant differences between the two groups in all measurements, except for the fall-related self-efficacy with OR = 1.8. Techniques for falling forwards and backwards displayed the highest OR = 124.1 and OR = 98.9. Physical function and balance showed OR = 3.3 and OR = 6.4. CONCLUSIONS: This exercise programme under study displayed significant differences in strength, balance and safe falling techniques between the groups. It is suggested that these functions, which were studied here, can effectively be trained in working-age adults by using the Judo4Balace exercise programme. Thus, it may be beneficial to further investigate and include training in proper falling techniques when designing fall prevention exercise programmes. Furthermore, it may be a novel way of addressing fall-related injuries, which are of utmost importance to prevent in near future. TRIAL REGISTRATION: NCT04294342 . Registered 4 March 2020 - The Impact of Specifically Adapted Judo-based Training Program on Risk Factors for Falls Among Adults - Full Text View - ClinicalTrials.gov.

Differences in nitric oxide airway diffusion after maximum oxygen uptake test in asthmatic and nonasthmatic elite junior cross-country skiers.

Asthma is common in cross-country skiers and is often treated with ß2-agonists and inhaled corticosteroids (ICS). Exhaled nitric oxide (NO) is often used to guide ICS treatment in asthma. This study investigated the change in pulmonary NO dynamics before and after a maximum oxygen uptake (V'O2 max) test. An extended NO analysis was performed among Swedish elite junior cross-country skiers (n=25), with and without declared asthma, before and after a V'O2 max test using roller skis. Asthma was declared by six boys and two girls among whom five occasionally used ICSs. There were no differences in baseline NO parameters between those with and without declared asthma. The median (interquartile range) diffusion capacity over airway wall (D awNO) was 21 (17-25) mL·s-1, which is much increased for this age group. After the V'O2 max test, there were statistically significant differences from the baseline fraction of exhaled NO (F ENO50 ), NO flux from airways, D awNO and alveolar NO values; but not in the NO content in airway wall (C awNO) for all subjects together as one group. However, in the asthma group, differences were only seen in F ENO50 and C awNO. Interestingly, a majority of the subjects had an increase in the D awNO. An increase in D awNO has been found with allergic asthma together with elevated C awNO. The skiers did not have elevated C awNO, which indicates an absence of inflammation in the airway wall. Modelling of lung NO production clearly shows that the asthma among our skiers is distinct from the allergic asthma in nonathletes.

Older adults' experiences with mHealth for fall prevention exercise: usability and promotion of behavior change strategies.

Background: With the rapidly growing aging population, older adults need to stay healthy and active for a longer time. Mobile health (mHealth) solutions could help support, prevent, or delay functional decline and falls in old age.Purpose: The aim was to explore older persons' experiences of a mobile application for fall prevention exercise, and to identify what possible behavior change techniques to include in the further development of the application.Methods: Two focus groups were conducted with 12 older adults (seven women and five men) 70 to 83 years of age. A qualitative content analysis was performed.Results: Two main results emerged: 1) external facilitators for using the application; and 2) internal facilitators for using the application and perceived gains, in addition 10 behavior change techniques were identified.Conclusion: With support, an application could be adapted for older adults to manage, motivate, and adhere to fall prevention exercise. To achieve long-term adherence to health behavior changes, behavior change strategies and techniques are recommended to be included in further development of the fallprevention application.

Feasibility of a novel Judo4Balance - fall preventive exercise programme targeting community-dwelling older adults.

OBJECTIVES: It is of utmost importance to investigate risk factors for falls and learning techniques for falling safely. Therefore, the aim of this study was to assess the feasibility of a novel judo-inspired exercise intervention for community-dwelling older adults. METHODS: We included 28 participants, 60-88 years of age, in this study. In three different settings, the feasibility of carrying out a full-scale study was evaluated by the following: the study process, resource management and scientific aspects. The outcome measures evaluated were physical performance, fall related self-efficacy and fall techniques (backwards and forwards) among the older adults. RESULTS: The intervention was judged to be feasible in the different settings used in this study. Some changes regarding duration of the intervention were suggested as being important. Significant improvements were seen in the selected outcome measures, physical performance (p=.030) and fall techniques (p=<.001). A corresponding difference was not found for fall related self- efficacy (p=.113). CONCLUSIONS: This study confirms the judo inspired exercise programme, Judo4Balance, to be a feasible intervention for active older adults. This study will provide a safe and thoroughly planned protocol for the planned study and provides indication of appropriate setting depending on the target group.

Health promotion and prevention: The impact of specifically adapted judo-inspired training program on risk factors for falls among adults.

Globally, falls and fall-related injuries constitute a severe threat to public health at all ages. New approaches are warranted since existing knowledge and actions have failed to reduce the incidence of falls and fall-related injuries, both at work and during leisure time. The purpose of this quasi-experimental study was to investigate the impact of a 10-week supervised judo-inspired exercise program, Judo4Balance, provided in a workplace setting among men and women targeting: physical functions, activity level, fall-related self-efficacy, and techniques for safe landing when falling. A total of 79 adults from seven different workplaces in Sweden, mean age 45 years (18-68), participated in the program. The study was conducted from May 2018 to June 2019. The 10-week exercise program performed in a workplace setting improved physical and psychological functions, as well as techniques for falling safely, factors of great importance to prevent falls and fall-related injuries among men and women. Therefore, it is suggested that the judo-inspired exercise program may be an effective tool in the quest to promote health and prevention of risk factors for falls and fall-related injuries among those of working age.

Fall Prevention Exercises With or Without Behavior Change Support for Community-Dwelling Older Adults: A Two-Year Follow-Up of a Randomized Controlled Trial.

This study investigates the effectiveness of two fall prevention exercise interventions targeting physical performance, activity level, fall-related self-efficacy, health-related quality of life, and falls: the Otago Exercise Programme (OEP) with and the OEP without behavior change support. In this randomized controlled trial (RCT), 175 participants were randomised into two intervention groups and one control group. A total of 124 community-dwelling older adults over the age of 75 who needed walking aids or home support participated in the two-year follow-up. The OEP with and the OEP without support for behavior change displayed no long-term benefits on physical performance, fall-related self-efficacy, health-related quality of life, and falls compared to a control group. Although no significant differences were detected between the groups, the results implied the control group's physical activity level decreased compared to the intervention groups at two-year follow up.

Aerobic power and lean mass are indicators of competitive sprint performance among elite female cross-country skiers.

The purpose of this study was to establish the optimal allometric models to predict International Ski Federation's ski-ranking points for sprint competitions (FISsprint) among elite female cross-country skiers based on maximal oxygen uptake ( [Formula: see text]) and lean mass (LM). Ten elite female cross-country skiers (age: 24.5±2.8 years [mean ± SD]) completed a treadmill roller-skiing test to determine [Formula: see text] (ie, aerobic power) using the diagonal stride technique, whereas LM (ie, a surrogate indicator of anaerobic capacity) was determined by dual-emission X-ray anthropometry. The subjects' FISsprint were used as competitive performance measures. Power function modeling was used to predict the skiers' FISsprint based on [Formula: see text], LM, and body mass. The subjects' test and performance data were as follows: [Formula: see text], 4.0±0.3 L min-1; LM, 48.9±4.4 kg; body mass, 64.0±5.2 kg; and FISsprint, 116.4±59.6 points. The following power function models were established for the prediction of FISsprint: [Formula: see text] and 6.95 × 1010 · LM-5.25; these models explained 66% (P=0.0043) and 52% (P=0.019), respectively, of the variance in the FISsprint. Body mass failed to contribute to both models; hence, the models are based on [Formula: see text] and LM expressed absolutely. The results demonstrate that the physiological variables that reflect aerobic power and anaerobic capacity are important indicators of competitive sprint performance among elite female skiers. To accurately indicate performance capability among elite female skiers, the presented power function models should be used. Skiers whose [Formula: see text] differs by 1% will differ in their FISsprint by 5.8%, whereas the corresponding 1% difference in LM is related to an FISsprint difference of 5.1%, where both differences are in favor of the skier with higher [Formula: see text] or LM. It is recommended that coaches use the absolute expression of these variables to monitor skiers' performance-related training adaptations linked to changes in aerobic power and anaerobic capacity.

Physiological Demands of Competitive Sprint and Distance Performance in Elite Female Cross-Country Skiing.

Carlsson, M, Carlsson, T, Wedholm, L, Nilsson, M, Malm, C, and Tonkonogi, M. Physiological demands of competitive sprint and distance performance in elite female cross-country skiing. J Strength Cond Res 30(8): 2138-2144, 2016-The purpose was to investigate the relationship between elite females' competitive performance capability in sprint and distance cross-country skiing and the variables of gross efficiency (GE), work rate at the onset of blood-lactate accumulation (OBLA4mmol), maximal oxygen uptake (V[Combining Dot Above]O2max), maximal speed (Vmax), and peak upper-body oxygen uptake (V[Combining Dot Above]O2peak). Ten elite female cross-country skiers (age 24.5 ± 2.8 years) completed treadmill roller-skiing tests to determine GE, OBLA4mmol, and V[Combining Dot Above]O2max using the diagonal-stride technique as well as Vmax and V[Combining Dot Above]O2peak using the double-poling technique. International Ski Federations ranking points for sprint (FISsprint) and distance (FISdist) races were used as competitive performance data. There were correlations between the FISsprint and the V[Combining Dot Above]O2max expressed absolutely (p = 0.0040), Vmax (p = 0.012), and V[Combining Dot Above]O2peak expressed absolutely (p < 0.001) and as a simple ratio-standard (p = 0.049). The FISdist were correlated with OBLA4mmol (p = 0.048), V[Combining Dot Above]O2max expressed absolutely (L·min) (p = 0.015) and as a simple ratio-standard (p = 0.046), and V[Combining Dot Above]O2peak expressed absolutely (p = 0.036) and as a simple ratio-standard (ml·min·kg) (p = 0.040). The results demonstrate that the physiological abilities reflected by V[Combining Dot Above]O2max and V[Combining Dot Above]O2peak are indicators of competitive sprint and distance performance in elite female cross-country skiing. In addition, the ability to generate a high Vmax indicates the performance in sprint races, whereas the skier's OBLA4mmol reflects the performance capability in distance races. Based on the results, when evaluating the performance capacity of elite female cross-country skiers, it is recommended to use physiological variables that reflect competitive performance.

Motivation towards dual career of European student-athletes.

The present study aimed to investigate motivations for the dual career of European student-athletes living in countries providing different educational services for elite athletes: State-centric regulation-State as sponsor/facilitator (State), National Sporting Federations/Institutes as intermediary (Federation) and Laisser Faire, no formal structures (No Structure). Therefore, the European Student-athletes' Motivation towards Sports and Academics Questionnaire (SAMSAQ-EU) was administered to 524 European student-athletes. Exploratory Factor Analysis, and Confirmatory Factor Analysis were applied to test the factor structure, and the reliability and validity of the SAMSAQ-EU, respectively. A multivariate approach was applied to verify subgroup effects (P ≤ 0.05) according to gender (i.e., female and male), age (i.e., ≤ 24 years, > 24 years), type of sport (i.e., individual sport and team sport) and competition level (i.e., national and international). Insufficient confirmatory indexes were reported for the whole European student-athlete group, whereas distinct three factor models [i.e., Student Athletic Motivation (SAM); Academic Motivation (AM); Career Athletic Motivation (CAM)] emerged, with acceptable reliability estimates, for State (SAM = 0.82; AM = 0.75; and CAM = 0.75), Federation (SAM = 0.82; AM = 0.66; and CAM = 0.87) and No Structure (SAM = 0.78; AM = 0.74; and CAM = 0.79) subgroups. Differences between subgroups were found only for competition level (P < 0.001) in relation to SAM (P = 0.001) and CAM (P < 0.001). For SAM, the highest and lowest values emerged for Federation (national, 5.1 ± 0.5; international, 5.4 ± 0.5) and State (national, 4.5 ± 0.9; international, 4.8 ± 0.7). The opposite picture emerged for CAM (Federation: national, 3.3 ± 0.7; international, 3.5 ± 0.9; State: national, 5.0 ± 0.8; international, 5.0 ± 0.9). Therefore, despite SAMSAQ-EU demonstrated to be a useful tool, results showed that European student-athletes' motivation for dual career has to be specifically investigated according to social contexts.

Optimal [Formula: see text] ratio for predicting 15 km performance among elite male cross-country skiers.

The aim of this study was 1) to validate the 0.5 body-mass exponent for maximal. oxygen uptake [Formula: see text] as the optimal predictor of performance in a 15 km classical-technique skiing competition among elite male cross-country skiers and 2) to evaluate the influence of distance covered on the body-mass exponent for [Formula: see text] among elite male skiers. Twenty-four elite male skiers (age: 21.4±3.3 years [mean ± standard deviation]) completed an incremental treadmill roller-skiing test to determine their [Formula: see text]. Performance data were collected from a 15 km classical-technique cross-country skiing competition performed on a 5 km course. Power-function modeling (ie, an allometric scaling approach) was used to establish the optimal body-mass exponent for [Formula: see text] to predict the skiing performance. The optimal power-function models were found to be [Formula: see text] and [Formula: see text], which explained 69% and 81% of the variance in skiing speed, respectively. All the variables contributed to the models. Based on the validation results, it may be recommended that [Formula: see text] divided by the square root of body mass (mL · min(-1) · kg(-0.5)) should be used when elite male skiers' performance capability in 15 km classical-technique races is evaluated. Moreover, the body-mass exponent for [Formula: see text] was demonstrated to be influenced by the distance covered, indicating that heavier skiers have a more pronounced positive pacing profile (ie, race speed gradually decreasing throughout the race) compared to that of lighter skiers.

Oxygen uptake at different intensities and sub-techniques predicts sprint performance in elite male cross-country skiers.

PURPOSE: To investigate the relationship between sprint-prologue performance (using the classical technique) and the oxygen uptake at the lactate threshold (VO2obla), maximal oxygen uptake (VO2max), and mean oxygen uptake during double poling (VO2dp). METHODS: Eight elite male cross-country skiers [age 24.8 ± 4.8 years, (mean ± SD)] completed two treadmill roller-skiing tests using the diagonal-stride technique and a 60 s double-poling test on a ski-ergometer to determine their VO2obla, VO2max, and VO2dp. Performance data were generated from a 1.25 km sprint prologue. Power-function modelling was used to predict the skiers' race speeds based on the oxygen-uptake variables and body mass. RESULTS: There were correlations between the race speed and the absolute expression of the VO2obla (r = 0.79, P = 0.021), VO2max (r = 0.86, P = 0.0069), and VO2dp (r = 0.94, P = 0.00062). The following power-function models were established for race-speed prediction: 1.09 · VO2obla(0.21), 1.05 · VO2max(0.21), and 1.19 · VO2dp(0.20); these models explained 60% (P = 0.024), 73% (P = 0.0073), and 87% (P = 0.00073), respectively, of the variance in the race speed. However, body mass did not contribute to any of the models (P = 0.97, 0.88, and 0.21, respectively). CONCLUSIONS: Oxygen uptake at different intensities and sub-techniques is an indicator of elite male sprint-prologue performance. The absolute expression of the investigated oxygen-uptake variables should be used when evaluating elite male sprint-prologue performances; if skiers oxygen uptake differs by 1%, their performances will likely differ by 0.2% in favour of the skier with higher oxygen uptake.

Prediction of race performance of elite cross-country skiers by lean mass.

PURPOSE: To investigate the relationship between race performance and lean mass (LM) variables, as well as to examine sex differences in body composition in elite-standard cross-country skiers. METHODS: Thirty-four elite cross-country skiers (18 men and 16 women) underwent a dual-emission X-ray-absorptiometry body-composition test to determine LM, fat mass, and bone mineral content. For both sexes, performance data were collected from a sprint prologue and a distance race. RESULTS: The absolute expression of LM variables (whole-body [LMWB], upper body [LMUB], and lower body [LMLB]) was significantly correlated with finishing time in the sprint prologue independent of sex. Distance-race performance was significantly related to LMWB, LMUB, and LMLB in women; however, no correlation was found in men. Men had a significantly higher LM and lower fat mass, independent of expression (absolute or relative), for the whole body, arms, trunk, and legs, except for the absolute fat mass in the trunk. CONCLUSIONS: The absolute expressions of LMWB, LMUB, and LMLB were significant predictors of sprint-prologue performance in both sexes, as well as of distance-race performance in women only. Compared with women, male skiers have a higher LM in the body segments that are major contributors to propelling forces. These results suggest that muscle mass in the lower and upper body is equally important for race performance; thus, more focus of elite skiers' training should be directed to increasing whole-body muscle mass to improve their competitive performance capability.

Time trials predict the competitive performance capacity of junior cross-country skiers.

PURPOSE: This study investigated whether there is a correlation between time-trial performance and competitive performance capacity of male and female junior cross-country skiers and sought to explain sex-specific competitive performance capacity through multiple-regression modeling. METHODS: The International Ski Federation's (FIS) junior ranking points for distance (FISdist) and sprint (FISsprint) competitions were used as performance parameters. A total of 38 elite junior (age 18.5 ± 1.0 y) cross-country skiers (24 men and 14 women) completed 3 time-trial tests: a 3-km level-running time trial (TTRun), a 2-km moderate uphill (1.2° slope) roller-skiing time trial using the double-poling technique (TTDP), and a 2-km uphill (2.8° slope) roller-skiing time trial using the diagonal-stride technique (TTDiag). The correlations were investigated using Pearson correlation analysis, and regression models were created using multiple-linear-regression analysis. RESULTS: For men, FISsprint and FISdist were correlated with the times for TTRun, TTDP, and TTDiag (all P < .001). For women, FISsprint was correlated with the times for TTRun (P < .05), TTDP (P < .01), and TTDiag (P < .01), whereas FISdist was correlated only with the times for TTDP (P < .01) and TTDiag (P < .05). The models developed for FISdist and FISsprint explained 73.9-82.3% of the variance in the performance capacity of male junior cross-country skiers. No statistically valid regression model was found for the women. CONCLUSIONS: Running and roller-skiing time trials are useful tests for accurately predicting the performance capacity of junior cross-country skiers.

Scaling maximal oxygen uptake to predict performance in elite-standard men cross-country skiers.

The purpose of this study was to: 1) establish the optimal body-mass exponent for maximal oxygen uptake (VO(2)max) to indicate performance in elite-standard men cross-country skiers; and 2) evaluate the influence of course inclination on the body-mass exponent. Twelve elite-standard men skiers completed an incremental treadmill roller-skiing test to determine VO(2)max and performance data came from the 2008 Swedish National Championship 15-km classic-technique race. Log-transformation of power-function models was used to predict skiing speeds. The optimal models were found to be: Race speed = 7.86 · VO(2)max · m(-0.48) and Section speed = 5.96 · [VO(2)max · m(-(0.38 + 0.03 · α)) · e(-0.003 · Δ) (where m is body mass, α is the section's inclination and Δ is the altitude difference of the previous section), that explained 68% and 84% of the variance in skiing speed, respectively. A body-mass exponent of 0.48 (95% confidence interval: 0.19 to 0.77) best described VO(2)max as an indicator of performance in elite-standard men skiers. The confidence interval did not support the use of either "1" (simple ratio-standard scaled) or "0" (absolute expression) as body-mass exponents for expressing VO(2)max as an indicator of performance. Moreover, results suggest that course inclination increases the body-mass exponent for VO(2)max.

Scaling of upper-body power output to predict time-trial roller skiing performance.

The purpose of the present study was to establish the most appropriate allometric model to predict mean skiing speed during a double-poling roller skiing time-trial using scaling of upper-body power output. Forty-five Swedish junior cross-country skiers (27 men and 18 women) of national and international standard were examined. The skiers, who had a body mass (m) of 69.3 ± 8.0 kg (mean ± s), completed a 120-s double-poling test on a ski ergometer to determine their mean upper-body power output (W). Performance data were subsequently obtained from a 2-km time-trial, using the double-poling technique, to establish mean roller skiing speed. A proportional allometric model was used to predict skiing speed. The optimal model was found to be: Skiing speed = 1.057 · W (0.556) · m (-0.315), which explained 58.8% of the variance in mean skiing speed (P < 0.001). The 95% confidence intervals for the scaling factors ranged from 0.391 to 0.721 for W and from -0.626 to -0.004 for m. The results in this study suggest that allometric scaling of upper-body power output is preferable for the prediction of performance of junior cross-country skiers rather than absolute expression or simple ratio-standard scaling of upper-body power output.

Validation of physiological tests in relation to competitive performances in elite male distance cross-country skiing.

The purpose of the present study was to establish which physiological test parameters reflects the distance performances in the Swedish National Championships in cross-country skiing (SNC) and the International Ski Federation's ranking points for distance performances (FISdist). The present study also aimed to create multiple regression models to describe skiing performance for the SNC distance races and International Ski Federation's (FIS) ranking. Twelve male, Swedish, national elite, cross-country skiers (maximal oxygen consumption [·VO2max] = 5.34 ± 0.34 L·min⁻¹) volunteered to participate in the study. Their results in the 2008 SNC (15 km race [SNC15] and 30 km race [SNC30]) and FISdist points were used as performance data. On the week preceding the Championship, subjects completed a test battery consisting of 7 physiological tests: isokinetic knee extension peak torque (PT), vertical jumps (VJ), lactate threshold (LT), ·VO2max, and 3 double poling tests of different durations (DP20, DP60, and DP360). Correlations were established using Pearson's correlation analysis, and models to describe skiing performance were created using standard multiple linear regression analysis. Significant correlations were found between the performance parameters and test parameters derived from LT, ·VO2max, and DP60 tests. No correlations with any performance parameter were found for PT, VJ, DP20, and DP360 tests. For FISdist and SNC15, the models explain 81% and 78% of the variance in performance, respectively. No statistically valid regression model was found for SNC30. The results of this study imply that the physiological demands in male elite distance cross-country skiing performances are different in different events. To adequately evaluate a skier's performance ability in distance cross-country skiing, it is necessary to use test parameters and regression models that reflect the specific performance.

Mitochondrial gene expression in elite cyclists: effects of high-intensity interval exercise.

Little is known about the effect of training on genetic markers for mitochondrial biogenesis in elite athletes. We tested the hypothesis that low-volume sprint interval exercise (SIE) would be as effective as high-volume interval exercise (IE). Ten male cyclists competing on national elite level (W (max) 403 ± 13 W, VO(2peak) 68 ± 1 mL kg(-1) min(-1)) performed two interval exercise protocols: 7 × 30-s "all-out" bouts (SIE) and 3 × 20-min bouts at ~87% of VO(2peak) (IE). During IE, the work was eightfold larger (1,095 ± 43 vs. 135 ± 5 kJ) and the exercise duration 17 times longer (60 vs. 3.5 min) than during SIE. Muscle samples were taken before and 3 h after exercise. The mRNA of upstream markers of mitochondrial biogenesis [peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1α), PGC-1α-related coactivator (PRC) and peroxisome proliferator-activated receptor δ (PPARδ)] increased to the same extent after SIE and IE (6-, 1.5- and 1.5-fold increase, respectively). Of the downstream targets of PGC-1α, mitochondrial transcription factor A (Tfam) increased only after SIE and was significantly different from that after IE (P < 0.05), whereas others increased to the same extent (pyruvate dehydrogenase kinase, PDK4) or was unchanged (nuclear respiratory factor 2, NRF2). We conclude that upstream genetic markers of mitochondrial biogenesis increase in a similar way in elite athletes after one exercise session of SIE and IE. However, since the volume and duration of work was considerably lower during SIE and since Tfam, the downstream target of PGC-1α, increased only after SIE, we conclude that SIE might be a time-efficient training strategy for highly trained individuals.