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Tim Veneman, Wouter Schallig, Maaike Eken, Carl Foster, and Jos J. de Koning

Background: During self-paced (SP) time trials (TTs), cyclists show unconscious nonrandom variations in power output of up to 10% above and below average. It is unknown what the effects of variations in power output of this magnitude are on physiological, neuromuscular, and perceptual variables. Purpose: To describe physiological, neuromuscular, and perceptual responses of 10-km TTs with an imposed even-paced (EP) and variable-paced (VP) workload. Methods: Healthy male, trained, task-habituated cyclists (N = 9) completed three 10-km TTs. First, an SP TT was completed, the mean workload from which was used as the mean workload of the EP and VP TTs. The EP was performed with an imposed even workload, while VP was performed with imposed variations in workload of ±10% of the mean. In EP and VP, cardiorespiratory, neuromuscular, and perceptual variables were measured. Results: Mean rating of perceived exertion was significantly lower in VP (6.13 [1.16]) compared with EP (6.75 [1.24]), P = .014. No mean differences were found for cardiorespiratory and almost all neuromuscular variables. However, differences were found at individual kilometers corresponding to power-output differences between pacing strategies. Conclusion: Variations in power output during TTs of ±10%, simulating natural variations in power output that are present during SP TTs, evoke minor changes in cardiorespiratory and neuromuscular responses and mostly affect the perceptual response. Rating of perceived exertion is lower when simulating natural variations in power output, compared with EP cycling. The imposed variations in workload seem to provide a psychological rather than a physiological or neuromuscular advantage.

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Gerard E. McMahon, Lee-Ann Sharp, and Rodney A. Kennedy

Purpose: To compare the global positioning system– and accelerometry-derived running demands, creatine kinase (CK), and self-reported wellness during an Olympic Games in international hockey. Methods: Data were collected across 5 games during the 2016 Rio Olympic Games. Global positioning system units (10 Hz) were used to assess the running demands, accelerations, and decelerations of outfield players in a men’s hockey squad with matches 2 to 5 compared with match 1. CK was used as a marker of muscle damage, and self-reported psychometric questionnaires were used to assess wellness, with each of the 5 matches compared with precompetition assessments. Results: There were significant increases (P < .05) in either, or both, absolute and relative total distance, player load, high-speed running distance, sprint distance, and accelerations and decelerations, compared with baseline. There was a significant decrease (P < .05) in maximal velocity by match 5. CK significantly increased from match 1 to 5 and displayed significant correlations with total distance (r = .55) and player load (r = .41). Muscle soreness correlated with total distance and player load, with other wellness markers unchanged compared with baseline. Conclusions: International hockey athletes may maintain or increase running activities over the course of an Olympic tournament; however, this may be impacted by situational (match score/outcome) and environmental (ambient temperature) factors. Despite CK and muscle soreness displaying relationships with running variables, further work is needed to establish their individual value in monitoring international hockey athletes.

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James R. Mckee, Bradley A. Wall, and Jeremiah J. Peiffer

Purpose: To examine the influence of temporal location of high-intensity interval training (HIIT) within a cycling session on the time spent ≥90% of maximal oxygen consumption and physiological and perceptual responses. Methods: In a randomized, crossover design, 16 trained cyclists (male, n = 13 and female, n = 3) completed three 90-minute cycling sessions with HIIT placed at the beginning, middle, or end of the session (13, 36, and 69 min, respectively). Intervals consisted of three 3-minute efforts at 90% of the power output associated with maximal oxygen consumption interspersed with 3 minutes of recovery. Oxygen consumption, minute ventilation, respiratory rate, and heart rate were recorded continuously during work intervals. Rate of perceived exertion was recorded at the end of work intervals, and sessional rate of perceived exertion was collected 20 minutes after session completion. Results: No differences were observed for mean oxygen consumption (P = .479) or time spent ≥90% maximal oxygen consumption (P = .753) between condition. The mean rate of perceived exertion of all intervals were greater in the Middle (P < .01, effect size = 0.83) and End (P < .05, effect size = 0.75) compared with Beginning conditions. Mean minute ventilation was greater in the End compared with Beginning condition (P = .015, effect size = 0.63). However, no differences in mean respiratory rate were observed between conditions (P = .297). Conclusions: Temporal location of HIIT has no impact on oxygen consumption or cardiovascular stress within a cycling session. However, HIIT performed later in the session resulted in higher ventilation, which may indicate the need for greater anaerobic contribution to these intervals.

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Johanna K. Ihalainen, Oona Kettunen, Kerry McGawley, Guro Strøm Solli, Anthony C. Hackney, Antti A. Mero, and Heikki Kyröläinen

Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined. Methods: Altogether 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study. Results: ATH had significantly lower body mass (P < .008), fat percentage (P < .001), and body mass index (P < .027) compared with CON, while energy availability did not differ between ATH and CON. The Low Energy Availability in Females Questionnaire score was higher in ATH than in CON (P < .028), and 8 ATH (vs zero CON) were AME. The AME had significantly more injury days (P < .041) and ran less (P < .046) than EUM, while total annual running distance was positively related to changes in performance in ATH (r < .62, P < .043, n < 11). Conclusions: More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.

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Ryo Yamanaka, Shinya Wakasawa, Koya Yamashiro, Naoki Kodama, and Daisuke Sato

Purpose: The study determined whether the increase in the cross-sectional area (CSA) of psoas major, which is known as a hip-flexion muscle, by resistance training combined with running training improves the performance of long-distance runners. Methods: Subjects were 8 well-trained male long-distance runners. The personal best time in a 5000-m race was 15:10.0 (0:20.5) (mean [SD]). Each subject performed resistance training twice per week with running training for 12 weeks. The authors used 3 resistance training regimens that would train the hip flexor muscles. Training intensity was a maximum of 10 repetitions. The training amount was 3 sets × 10 times during the first 4 weeks followed by 4 sets × 10 times during the last 8 weeks. The authors measured the CSA of psoas major using magnetic resonance imaging and the performance of long-distance runners using a constant velocity running test before (pre) and after (post) the training term. Results: The combination training significantly (P < .01, d = 0.34) increased the CSA of psoas major (pre: 16.2 [1.5] cm2, post: 16.7 [1.4] cm2) and significantly (P < .01, d = 1.41) improved the duration of the constant velocity running test (pre: 500 [108] s, post: 715 [186] s). Moreover, multiple regression analysis showed that the pre to post change in the duration of the constant velocity exercise was significantly correlated with the change in CSA of the psoas major. Conclusion: The authors suggest that resistance training of psoas major with running training is correlated with an improvement in the performance of long-distance runners.

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Sebastien Racinais, Julien D. Périard, Julien Piscione, Pitre C. Bourdon, Scott Cocking, Mohammed Ihsan, Mathieu Lacome, David Nichols, Nathan Townsend, Gavin Travers, Mathew G. Wilson, and Olivier Girard

Purpose: To investigate whether including heat and altitude exposures during an elite team-sport training camp induces similar or greater performance benefits. Methods: The study assessed 56 elite male rugby players for maximal oxygen uptake, repeated-sprint cycling, and Yo-Yo intermittent recovery level 2 (Yo-Yo) before and after a 2-week training camp, which included 5 endurance and 5 repeated-sprint cycling sessions in addition to daily rugby training. Players were separated into 4 groups: (1) control (all sessions in temperate conditions at sea level), (2) heat training (endurance sessions in the heat), (3) altitude (repeated-sprint sessions and sleeping in hypoxia), and (4) combined heat and altitude (endurance in the heat, repeated sprints, and sleeping in hypoxia). Results: Training increased maximal oxygen uptake (4% [10%], P = .017), maximal aerobic power (9% [8%], P < .001), and repeated-sprint peak (5% [10%], P = .004) and average power (12% [14%], P < .001) independent of training conditions. Yo-Yo distance increased (16% [17%], P < .001) but not in the altitude group (P = .562). Training in heat lowered core temperature and increased sweat rate during a heat-response test (P < .05). Conclusion: A 2-week intensified training camp improved maximal oxygen uptake, repeated-sprint ability, and aerobic performance in elite rugby players. Adding heat and/or altitude did not further enhance physical performance, and altitude appears to have been detrimental to improving Yo-Yo.

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Patricia Rehder-Santos, Raphael M. Abreu, Étore De F. Signini, Claudio D. da Silva, Camila A. Sakaguchi, Carla C. Dato, and Aparecida M. Catai

Background and Objective: Inspiratory muscle training (IMT) produced outstanding results in the physical performance of active subjects; however, little is known about the best training intensity for this population. The objective was to investigate the impact of an IMT of high intensity, using the critical inspiratory pressure (CIP), on inspiratory muscle strength (IMS), inspiratory muscle endurance (IME), peak power, and oxygen uptake of recreational cyclists; and to compare these results with moderate-intensity IMT (60% of maximal inspiratory pressure [MIP]). Methods: Thirty apparently healthy male recreational cyclists, 20–40 years old, underwent 11 weeks of IMT (3 times per week; 55 min per session). Participants were randomized into 3 groups: sham group (6 cmH2O; n = 8); 60% MIP (MIP60; n = 10) and CIP (n = 12). All participants performed the IMS test and incremental IME test at the first, fifth, ninth, and 13th weeks of the experimental protocol. Cardiopulmonary exercise testing was performed on an electromagnetic braking cycle ergometer pre-IMT and post-IMT. Data were analyzed using a 2-way repeated measures ANOVA (group and period factors). Results: IMS increased in CIP and MIP60 groups at the ninth and 13th weeks compared with the sham group (P < .001; β = 0.99). Regarding IME, there was an interaction between the CIP and MIP60 groups in all periods, except in the initial evaluation (P < .001; β = 1.00). Peak power (in watts) increased after IMT in CIP and MIP60 groups (P = .01; β = 0.67). Absolute oxygen uptake did not increase after IMT (P = .49; β = 0.05). Relative oxygen uptake to lean mass values did not change significantly (P = .48; β = 0.05). Conclusion: High-intensity IMT is beneficial on IMS, IME, and peak power, but does not provide additional gain to moderate intensity in recreational cyclists.

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Adrien Vachon, Nicolas Berryman, Iñigo Mujika, Jean-Baptiste Paquet, and Laurent Bosquet

Purpose: To assess the effects of a short-term taper on the ability to perform repeated high-intensity efforts, depending on players’ fatigue level following an intensive training block. Method: After a 3-day off-season camp, 13 players followed the same 3-week preseason training block followed by a 7-day exponential taper. Performance was assessed by a repeated high-intensity effort test before and after the taper. Total sprint time, percentage of decrement, and the number of sprints equal to or higher than 90% of the best sprint were retained for analysis. Players were a posteriori classified in normal training or acute fatigue groups based on their readiness to perform prior to the taper, assessed through the magnitude of difference in psychological (Profile of Mood State Questionnaire), cardiovascular (submaximal constant-duration cycling), and neuromuscular (countermovement jump) tests between the preintensive and postintensive training blocks. Results: Training load declined by 55% (9%) during the taper (P = .001, g = −2.54). The overall group showed a small improvement in total sprint time (−3.40% [3.90%], P = .04, g = −0.39) following the taper. Relative changes tended to be higher in the acute fatigue compared with the normal training group (−5.07% [4.52%] vs −1.45% [1.88%], respectively; P = .08; d = 1.01). No taper-induced improvement was observed in percentage of decrement or number of sprints equal to or higher than 90% of the best sprint. Conclusion: A 7-day taper consisting of 55% training load reduction improved repeated high-intensity effort performance in young elite rugby union players. Pretaper level of fatigue seems to be a key determinant in the taper supercompensation process, as acutely fatigued players at the end of the intensive training block tended to benefit more from the taper.

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Maria Jose Arias-Tellez, Francisco M. Acosta, Jairo H. Migueles, Jose M. Pascual-Gamarra, Elisa Merchan-Ramirez, Clarice M. de Lucena Martins, Jose M. Llamas-Elvira, Borja Martinez-Tellez, and Jonatan R. Ruiz

The role of lifestyle behaviors on neck adipose tissue (NAT), a fat depot that appears to be involved in the pathogenesis of different cardiometabolic diseases and in inflammatory status, is unknown. In this cross-sectional and exploratory study, the authors examined the relationship between sedentary time and physical activity (PA) with neck adiposity in young adults. A total of 134 subjects (69% women, 23 ± 2 years) were enrolled. The time spent in sedentary behavior and PA of different intensity were objectively measured for 7 consecutive days (24 hr/day), using a wrist (nondominant)-worn accelerometer. The NAT volume was assessed using computed tomography, and the compartmental (subcutaneous, intermuscular, and perivertebral) and total NAT volumes were determined at the level of vertebra C5. Anthropometric indicators and body composition (by dual-energy X-ray absorptiometry) were determined. The time spent in light physical activity and moderate physical activity (MPA) and the overall PA were inversely associated with the intermuscular NAT volume in men, as were the MPA and overall PA with total NAT volume (all ps ≤ .04). Sedentary time was directly related to the total NAT volume (p = .04). An opposite trend was observed in women, finding a direct relationship of MPA with the subcutaneous NAT; of light physical activity, MPA, and overall PA with the perivertebral NAT; and of light physical activity with total NAT volumes (all ps ≤ .05). The observed associations were weak, and after adjusting for multiplicity, the results became nonsignificant (p > .05). These findings suggest that the specific characteristics of PA (time and intensity) might have sex-dependent implications in the accumulation of NAT.

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Jonne A. Kapteijns, Kevin Caen, Maarten Lievens, Jan G. Bourgois, and Jan Boone

Purpose: To determine if there is a link between the demands of competitive game activity and performance profiles of elite female field hockey players. Methods: Global positioning systems (GPS) were used to quantify running performance of elite female field hockey players (N = 20) during 26 competitive games. Performance profiles were assessed at 2 time points (preseason and midseason) for 2 competitive seasons. A battery of anthropometric and performance field-based tests (30–15 intermittent fitness test, incremental run test, 10–30-m speed test, T test, and vertical jump test) were used to determine the performance profiles of the players. Results: Players covered a mean total distance of 5384 (835) m, of which 19% was spent at high intensities (zone 5: 796 [221] m; zone 6: 274 [105] m). Forwards covered the lowest mean total distance (estimated marginal means 4586 m; 95% confidence interval, 4275–4897), whereas work rate was higher in forwards compared with midfielders (P = .006, d = 0.43) and central defenders (P = .001, d = 1.41). Players showed an improvement in body composition and anaerobic performance from preseason to midseason. Aerobic performance capacity (maximal oxygen uptake and speed at the 4-mM lactate threshold) was positively correlated with high-intensity activities. Conclusions: There is a clear relationship between running performance and aerobic performance profiles in elite female hockey players. These results highlight the importance of a well-developed aerobic performance capacity in order to maintain a high performance level during hockey games.