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Guro Strøm Solli, Espen Tønnessen and Øyvind Sandbakk

Purpose: To investigate the factors associated with underperformance and the subsequent changes in training characteristics and supportive actions when returning to the world’s best cross-country skier. Methods: The participant is the most decorated winter Olympian, with 8 Olympic gold medals, 18 World Championship titles, and 114 World Cup victories. Training data were categorized by training form (endurance, strength, and speed); intensity (low, moderate, and high); and mode (running, cycling, and skiing/roller skiing). In addition, test data were retrospectively analyzed, and interviews were performed with the participant and her support team. Results: After the competitive season, the participant had 8 weeks without systematic training and an evaluation process aiming to detect the factors contributing to underperformance. Here physiological, technical, and psychological challenges were detected. As a consequence, the participant included less high-intensity training (1.2 vs 2.1 sessions/wk, P = .011); more moderate-intensity training (0.9 vs 0.4 sessions/wk, P = .016); and more low-intensity training (6.9 vs 5.9 sessions/wk, P = .036) during the general preparation phase but with similar total endurance training load as previous season. In addition, more strength training (1.6 vs 1.1 h/wk, P = .036) and new ski-specific strength exercises were included. Finally, the athlete’s autonomy when planning and adjusting training was increased, nontraining stressors were reduced, more frequent testing was included, systematic mental training was initiated, her nutritional strategy was adjusted, and her asthma treatment was optimized. Conclusions: Overall, the current case study could be used as a framework for the holistic approach to treating an overtraining condition and for generation of new hypothesis in this exiting area.

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José R. Alvero-Cruz, Robert A. Standley, Manuel Avelino Giráldez-García and Elvis A. Carnero

Background: Half-marathon races have become increasingly more popular with many recreational athletes all around the world. New and recreational runners are likely to have the greatest need for training advice to set running paces during long-distance races. Purpose: To develop a simple equation to estimate half-marathon time from the Cooper test and verify its validity. Methods: One hundred ninety-eight recreational runners (177 men and 21 women, 40 [6.8] years and 33.7 [8] years, respectively) participated in this study. All runners completed the Cooper test 7 to 10 days prior to races. A stepwise multiple regression analysis was performed to select the main predictors of half-marathon time. Results: Simple correlation analysis showed that Cooper test performance (distance) was a good construct to estimate half-marathon time (r = −.906; 95% confidence interval, −0.927 to −0.877; P < .0001). The authors also derived an equation with a high predictive validity (R 2 = .82; standard error of estimation = 5.19 min) and low systematic bias (mean differences between the predicted value and the criterion of 0.48 [5.2] min). Finally, the concordance coefficient of correlation (.9038) and proportional bias analysis (Kendall τ = −.0799; 95% confidence interval, −0.184 to 0.00453; P = .09) confirmed a good concurrent validity. Conclusion: In this study, the authors derived an equation from the Cooper test data with a high predictive and concurrent validity and low bias.

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Nattai R. Borges, Aaron T. Scanlan, Peter R. Reaburn and Thomas M. Doering

Purpose: Due to age-related changes in the psychobiological state of masters athletes, this brief report aimed to compare training load responses using heart rate (HR) and ratings of perceived exertion (RPE) during standardized training sessions between masters and young cyclists. Methods: Masters (n = 10; 55.6 [5.0] y) and young (n = 8; 25.9 [3.0] y) cyclists performed separate endurance and high-intensity interval training sessions. Endurance intensity was set at 95% of ventilatory threshold 2 for 1 hour. High-intensity interval training consisted of 6 × 30-second intervals at 175% peak power output with 4.5-minute rest between intervals. HR was monitored continuously and RPE collected at standardized time periods during each session. Banister training impulse and summated-HR-zones training loads were also calculated. Results: Despite a significantly lower mean HR in masters cyclists during endurance (P = .04; d = 1.06 [±0.8], moderate) and high-intensity interval training (P = .01; d = 1.34 [±0.8], large), no significant differences were noted (P > .05) when responses were determined relative to maximum HR or converted to training impulse and summated-HR-zone loads. Furthermore, no interaction or between-group differences were evident for RPE across either session (P > .05). Conclusions: HR and RPE values were comparable between masters and young cyclists when relative HR responses and HR training load models are used. This finding suggests HR and RPE methods used to monitor or prescribe training load can be used interchangeably between masters and young athletes irrespective of chronological age.

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Nick Dobbin, Jamie Highton, Samantha L. Moss and Craig Twist

Purpose: To determine the utility of running-only and rugby-specific, in-season sprint interval interventions in professional rugby league players. Methods: Thirty-one professional academy rugby players were assigned to a rugby-specific (SITr/s, n = 16) or running-only (SITr, n = 15) sprint interval training group. Measures of speed, power, change of direction ability, prone Yo-Yo Intermittent Recovery Test (Yo-Yo IR1) performance, and heart rate recovery were taken before and after the 2-week intervention as were submaximal responses to the prone Yo-Yo IR1. Internal, external, and perceptual responses were collected during SITr/s and SITr, with well-being and neuromuscular function assessed before each session. Results: Despite contrasting (possible to most likely) internal, external, and perceptual responses to the SIT interventions, possible to most likely within-group improvements in physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1 were observed after both interventions. Between-group analysis favored the SITr/s intervention (trivial to moderate) for changes in 10-m sprint time, countermovement jump, change of direction, and medicine ball throw as well as submaximal (280–440 m) high metabolic power, PlayerLoad, and acceleration distance during the prone Yo-Yo IR1. Overall changes in well-being or neuromuscular function were unclear. Conclusions: Two weeks of SITr/s and SITr were effective for improving physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1, with no clear change in well-being and neuromuscular function. Between-group analysis favored the SITr/s group, suggesting that the inclusion of sport-specific actions should be considered for in-season conditioning of rugby league players.

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Jorge Carlos-Vivas, Jorge Perez-Gomez, Ola Eriksrud, Tomás T. Freitas, Elena Marín-Cascales and Pedro E. Alcaraz

Purpose: To analyze and compare the effects of 4 different resisted sprint training (RST) modalities on youth soccer players’ performance after 8 weeks of training. Methods: Forty-eight youth soccer players were first randomly assigned to 4 groups and only then completed 8 weeks of RST: horizontal resisted sprint, vertical resisted sprint (VRS), combined resisted sprint, and unresisted sprint. Performance in horizontal and vertical jumps, sprint, and change of direction (COD) ability were assessed 1 week before and after the training intervention. Magnitude-based inference analysis was performed for calculating within-group pre–post differences. In addition, an analysis of covariance test was performed for between-group comparison, using the pretest values as covariates. After that, the analysis of covariance P values and the effect statistic were transformed to magnitude-based inference. Results: Within-group outcomes showed that all resisted training modalities experienced improvements in sprint (small to moderate) and COD (small to large) performance. Moreover, all groups, except unresisted sprint, enhanced the horizontal jump performance. However, only VRS improved on vertical jump. Between-group comparison outcomes revealed that only VRS improved the sprint time compared with horizontal resisted sprint (moderate) and COD performance compared with all groups (moderate to large). In addition, VRS enhanced the countermovement jump performance (small to large) compared with the other groups. Conclusions: Independent of the orientation of the resistance applied, RST is an effective training method for improving sprinting and COD performance. Nevertheless, VRS may promote greater improvements on sprint and COD ability and have a positive additional effect on countermovement jump performance and the reduction of COD deficit.

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Eva Piatrikova, Nicholas J. Willsmer, Ana C. Sousa, Javier T. Gonzalez and Sean Williams

Purpose: To monitor physiological, technical, and performance responses to individualized high-intensity interval training (HIIT) prescribed using the critical speed (CS) and critical stroke rate (CSR) concepts in swimmers completing a reduced training volume program (≤30 km·wk−1) for 15 weeks. Methods: Over the 15-week period, 12 highly trained swimmers (age 16 [1] y, height 179 [8] cm, weight 66 [8] kg) completed four 3-minute all-out tests to determine CS and the finite capacity to work above CS (D′), and four 200-m tests at CS to establish a CSR estimate. Combining CS and D′, 2 HIIT sessions designed as 5 × 3-minute intervals depleting 60% of D′ and 3 × 3.5-minute intervals depleting 80% of D′ were prescribed once per week, respectively. An additional HIIT session was prescribed using CS and CSR as 10 × 150 m or 200 m at CS with 2 cycles per minute lower stroke rate than the CSR estimate. Additional monitored variables included peak speed, average speed for 150 seconds (speed150s) and 180 seconds (speed180s), competition performance and stroke length (SL), stroke count (SC), and stroke index (SI) adopted at CS. Results: At the end of the intervention, swimmers demonstrated faster CS (mean change ± 90% confidence limits: +5.4 ± 1.6%), speed150s (+2.5 ± 0.9%), speed180s (+3.0 ± 0.9%), and higher stroke rate (+6.4 ± 3.0%) and stroke index (+4.2 ± 3.6%). D′ was reduced (−25.2 ± 7.5%), whereas peak speed, SL, and SC changed only trivially. The change in the swimmers’ personal best times in the first and second main event was −1.2 ± 1.3% and −1.6 ± 0.9%, respectively. Conclusion: HIIT prescribed based on the CS and CSR concepts was associated with improvements in several physiological, technical, and performance parameters in highly trained swimmers while utilizing time- and resource-efficient approach. This was achieved despite a ≥25% reduction in training volume.

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Mathias H. Kosack, Walter Staiano, Rasmus Folino, Mads B. Hansen and Simon Lønbro

Purpose: Several studies have examined the effect of MF on sport performance, but no studies have been conducted on badminton performance. The purpose of the present study was to examine the acute effect of mental fatigue (MF) on badminton performance in elite players. Methods: In total, 19 elite Danish badminton players completed 2 test days in randomized order, separated by 48 h. On day 1, to elicit MF, a 60-min incongruent Stroop task was performed. On day 2, 60 min of an emotionally neutral documentary was used for the control condition. After either condition, subjects performed a badminton-specific test (BST) where performance time was measured, as well as countermovement-jump height, heart rate, rating of perceived exertion, and lactate. Psychological questionnaires were answered under both conditions. Results: Subjects were significantly more mentally fatigued (P = .002) after the Stroop intervention than in the control. No differences between conditions were detected in the BST (control 32.43 [1.96] vs MF 32.43 [2.36] s; P = .99, Student t test). In addition, no effect of condition (P = .64), time (P = .14), or condition × time (P = .87) was found (2-way analysis of variance). Furthermore, no differences in heart rate, countermovement jump, or rating of perceived exertion were observed between conditions. Lactate showed no effect of condition (P = .46). Conclusion: Despite being more mentally fatigued after the Stroop test than in the control condition, performance was not negatively affected during a BST. In addition, no differences in physiological measures were observed.

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Anna E. Voskamp, Senna van den Bos, Carl Foster, Jos J. de Koning and Dionne A. Noordhof

Background: Gross efficiency (GE) declines during high-intensity exercise. Increasing extracellular buffer capacity might diminish the decline in GE and thereby improve performance. Purpose: To examine if sodium bicarbonate (NaHCO3) supplementation diminishes the decline in GE during a 2000-m cycling time trial. Methods: Sixteen male cyclists and 16 female cyclists completed 4 testing sessions including a maximal incremental test, a familiarization trial, and two 2000-m GE tests. The 2000-m GE tests were performed after ingestion of either NaHCO3 supplements (0.3 g/kg body mass) or placebo supplements (amylum solani, magnesium stearate, and sunflower oil capsules). The GE tests were conducted using a double-blind, randomized, crossover design. Power output, gas exchange, and time to complete the 2000-m time trials were recorded. Capillary blood samples were analyzed for blood bicarbonate, pH, and lactate concentration. Data were analyzed using magnitude-based inference. Results: The decrement in GE found after the 2000-m time trial was possibly smaller in the male and female groups after NaHCO3 than with placebo ingestion, with the effect in both groups combined being unclear. The effect on performance was likely trivial for males (placebo 164.2 [5.0] s, NaHCO3 164.3 [5.0] s; Δ0.1; ±0.6%), unclear for females (placebo 178.6 [4.8] s, NaHCO3 178.0 [4.3] s; Δ−0.3; ±0.5%), and very likely trivial when effects were combined. Blood bicarbonate, pH, and lactate concentration were substantially elevated from rest to pretest after NaHCO3 ingestion. Conclusions: NaHCO3 supplementation results in an unclear effect on the decrease in GE during high-intensity exercise and in a very likely trivial effect on performance.

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Gavriil G. Arsoniadis, Gregory C. Bogdanis, Gerasimos Terzis and Argyris G. Toubekis

Purpose: To examine the acute effect of dry-land strength training on physiological and biomechanical parameters in a subsequent swim training session. Methods: Twelve male swimmers (age: 19.0 [2.2] y, peak oxygen uptake: 65.5 [11.4] mL·kg−1·min−1) performed a 5 × 200-m test with progressively increasing intensity. Blood lactate (BL) concentration was measured after each 200-m bout, and the speed corresponding to 4 mmol·L−1 (V4) was calculated. In the experimental (EXP) and control (CON) conditions, swimmers participated in a swim training session consisting of 1000-m warm-up, a bout of 10-second tethered swimming sprint, and 5 × 400 m at V4. In EXP condition, swimmers completed a dry-land strength training session (load: 85% of 1-repetition maximum) 15 minutes before the swimming session. In CON condition, swimmers performed the swimming session only. Oxygen uptake, BL concentration, arm-stroke rate, arm-stroke length, and arm-stroke efficiency were measured during the 5 × 400 m. Results: Force in the 10-second sprint was not different between conditions (P = .61), but fatigue index was higher in the EXP condition (P = .03). BL concentration was higher in EXP condition and showed large effect size at the fifth 400-m repetition compared with CON condition (6.4 [2.7] vs 4.6 [2.8] mmol·L−1, d = 0.63). During the 5 × 400 m, arm-stroke efficiency remained unchanged, arm-stroke length was decreased from the third repetition onward (P = .01), and arm-stroke rate showed a medium increment in EXP condition (d = 0.23). Conclusions: Strength training completed 15 minutes before a swim training session caused moderate changes in biomechanical parameters and increased BL concentration during swimming. Despite these changes, swimmers were able to maintain force and submaximal speed during the endurance training session.

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Joel M. Garrett, Stuart R. Graham, Roger G. Eston, Darren J. Burgess, Lachlan J. Garrett, John Jakeman and Kevin Norton

Purpose: To determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football players. Methods: A total of 23 professional and semiprofessional Australian rules football players performed 6 CMJs and three 8-second 50-m runs every 30 seconds (SRT), 7 days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation, CV (±90% confidence intervals). Test–retest reliability was examined using the magnitude of the difference (effect size [±90% confidence interval]) from week 1 to week 2. The smallest worthwhile change was calculated as 0.25 × SD. Results: Good reliability (CVs = 6.6%–9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV less than smallest worthwhile change, indicating an ability to detect practically important changes in performance. Only peak velocity from the CMJ test possessed a CV less than smallest worthwhile change, exhibiting a limitation of this test in detecting practically meaningful changes within this environment. Conclusions: The results suggest that while all variables possess acceptable reliability, a SRT might offer to be a more sensitive monitoring tool than a CMJ test within high-performance Australian rules football, due to its greater ability for detecting practically important changes in performance.