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Ade B. Pratama and Tossaporn Yimlamai

Purpose: To compare the effectiveness of 3 recovery protocols on muscle oxygenation, blood lactate, and subsequent performance during a 200-m repeated swim session. Methods: Twelve collegte swimmers completed 3 sessions of 2 consecutive 200-m front-crawl trials separated by 1 of 3 recovery protocols: a 15-minute active recovery (AR), a 15-minute passive recovery (PR), and a combination of 5-minute AR and 10-minute PR (CR) in a counterbalanced design. Tissue saturation index at biceps femoris, blood lactate concentration, arterial oxygen saturation, and heart rate were measured at rest, immediately after the trial, and at 5, 10, and 15 minutes of recovery. Two-way analysis of variance (recovery × time) with repeated measures was used to determine measurement variables. A level of significance was set at P < .05. Results: No significant changes in swimming time were observed between trials (AR: 156.79 [4.09] vs 157.79 [4.23] s, CR: 156.50 [4.89] vs 155.55 [4.86] s, PR: 156.54 [4.70] vs 156.30 [4.52] s) across recovery conditions. Interestingly, tissue saturation index rapidly declined immediately after a 200-m swim and then gradually returned to baseline, with a greater value observed during CR compared with AR and PR after 15-minute recovery (P = .04). These changes were concomitant with significant reductions in blood lactate and heart rate during the recovery period (P = .00). Conclusion: The CR in the present study was more effective in enhancing muscle reoxygenation after a 200-m swim compared with AR and PR, albeit its beneficial effect on subsequent performance warrants further investigation.

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Milos R. Petrovic, Amador García-Ramos, Danica N. Janicijevic, Alejandro Pérez-Castilla, Olivera M. Knezevic and Dragan M. Mirkov

Purpose: To test whether the force–velocity (F–V) relationship obtained during a specific single-stroke kayak test (SSKT) and during nonspecific traditional resistance-training exercises (bench press and prone bench pull) could discriminate between 200-m specialists and longer-distance (500- and 1000-m) specialists in canoe sprint. Methods: A total of 21 experienced male kayakers (seven 200-m specialists and 14 longer-distance specialists) participated in this study. After a familiarization session, kayakers came to the laboratory on 2 occasions separated by 48 to 96 hours. In a randomized order, kayakers performed the SSKT in one session and the bench press and bench pull tests in another session. Force and velocity outputs were recorded against 5 loads in each exercise to determine the F–V relationship and related parameters (maximum force, maximum velocity, F–V slope, and maximum power). Results: The individual F–V relationships were highly linear for the SSKT (r = .990 [.908, .998]), bench press (r = .993 [.974, .999]), and prone bench pull (r = .998 [.992, 1.000]). The F–V relationship parameters (maximum force, maximum velocity, and maximum power) were significantly higher for 200-m specialists compared with longer-distance specialists (all Ps ≤ .047) with large effect sizes (≥0.94) revealing important practical differences. However, no significant differences were observed between 200-m specialists and longer-distance specialists in the F–V slope (P ≥ .477). Conclusions: The F–V relationship assessed during both specific (SSKT) and nonspecific upper-body tasks (bench press and bench pull) may distinguish between kayakers specialized in different distances.

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James A. Betts

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Erin L. McCleave, Katie M. Slattery, Rob Duffield, Stephen Crowcroft, Chris R. Abbiss, Lee K. Wallace and Aaron J. Coutts

Purpose: To examine whether concurrent heat and intermittent hypoxic training can improve endurance performance and physiological responses relative to independent heat or temperate interval training. Methods: Well-trained male cyclists (N = 29) completed 3 weeks of moderate- to high-intensity interval training (4 × 60 min·wk−1) in 1 of 3 conditions: (1) heat (HOT: 32°C, 50% relative humidity, 20.8% fraction of inspired oxygen, (2) heat + hypoxia (H+H: 32°C, 50% relative humidity, 16.2% fraction of inspired oxygen), or (3) temperate environment (CONT: 22°C, 50% relative humidity, 20.8% fraction of inspired oxygen). Performance 20-km time trials (TTs) were conducted in both temperate (TTtemperate) and assigned condition (TTenvironment) before (base), immediately after (mid), and after a 3-week taper (end). Measures of hemoglobin mass, plasma volume, and blood volume were also assessed. Results: There was improved 20-km TT performance to a similar extent across all groups in both TTtemperate (mean ±90% confidence interval HOT, −2.8% ±1.8%; H+H, −2.0% ±1.5%; CONT, −2.0% ±1.8%) and TTenvironment (HOT, −3.3% ±1.7%; H+H, −3.1% ±1.6%; CONT, −3.2% ±1.1%). Plasma volume (HOT, 3.8% ±4.7%; H+H, 3.3% ±4.7%) and blood volume (HOT, 3.0% ±4.1%; H+H, 4.6% ±3.9%) were both increased at mid in HOT and H+H over CONT. Increased hemoglobin mass was observed in H+H only (3.0% ±1.8%). Conclusion: Three weeks of interval training in heat, concurrent heat and hypoxia, or temperate environments improve 20-km TT performance to the same extent. Despite indications of physiological adaptations, the addition of independent heat or concurrent heat and hypoxia provided no greater performance benefits in a temperate environment than temperate training alone.

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Alejandro Pérez-Castilla and Amador García-Ramos

Objective: To compare the short-term effect of power- and strength-oriented resistance-training programs on the individualized load–velocity profiles obtained during the squat (SQ) and bench-press (BP) exercises. Methods: Thirty physically active men (age = 23.4 [3.5] y; SQ 1-repetition maximum [1RM] = 126.5 [26.7] kg; BP 1RM = 81.6 [16.7] kg) were randomly assigned to a power- (exercises: countermovement jump and BP throw; sets per exercise: 4–6; repetitions per set: 5–6; load: 40% 1RM) or strength-training group (exercises: SQ and BP; sets per exercise: 4–6; repetitions per set: 2–8; load: 70%–90% 1RM). The training program lasted 4 wk (2 sessions/wk). The individualized load–velocity profiles (ie, velocity associated with the 30%–60%–90% 1RM) were assessed before and after training through an incremental loading test during the SQ and BP exercises. Results: The power-training group moderately increased the velocity associated with the full spectrum of % 1RM for the SQ (effect size [ES] range: 0.70 to 0.93) and with the 30% 1RM for the BP (ES: 0.67), while the strength-training group reported trivial/small changes across the load–velocity spectrum for both the SQ (ES range: 0.00 to 0.35) and BP (ES range: −0.06 to −0.33). The power-training group showed a higher increase in the mean velocity associated with all % 1RM compared with the strength-training group for both the SQ (ES range: 0.54 to 0.63) and BP (ES range: 0.25 to 0.53). Conclusions: The individualized load–velocity profile (ie, velocity associated with different % 1RM) of lower-body and upper-body exercises can be modified after a 4-wk resistance-training program.

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Roland van den Tillaar, Erna von Heimburg and Guro Strøm Solli

Purpose: To compare the assessment of the maximal oxygen consumption (VO2max) in a traditional graded exercise test (GXT) with a 1-km self-paced running test on a nonmotorized treadmill in men and women. Methods: A total of 24 sport-science students (12 women: age 23.7 [7.7] y, body height 1.68 [0.02] m, body mass 66.6 [4.3] kg; 12 men: 22.1 [3.1] y, body height 1.82 [0.06] m, body mass 75.6 [11.0] kg) performed a traditional GXT on a motorized treadmill and a 1-km self-paced running test on a nonmotorized treadmill. VO2max, blood lactate, heart rate, and rating of perceived exertion, together with running velocity and duration at each test, were measured. Results: The main findings of the study were that the 1-km test produced significantly higher VO2max values (53.2 [9.9] vs 51.8 [8.8] mL/kg/min ) and blood lactate concentrations (11.9 [1.8] vs 11.1 [2.2] mmol/L) than the GXT (F ≥ 4.8, P ≤ .04, η 2 ≥ .18). However, after controlling for sex, these differences were only present in men (60.6 [8.1] vs 58.1 [8.0] mL/kg/min , P = .027). Peak running velocity was higher in the GXT than in the 1-km test (15.7 [2.7] vs 13.0 [2.8] km/h). Men had higher VO2max values and running velocities than women in both tests. However, men and women used approximately similar pacing strategies during the 1-km test. Conclusions: Higher VO2max values were observed in a 1-km self-paced test than in the GXT. This indicates that a 1-km running test performed on a nonmotorized treadmill could serve as a simple and sport-specific alternative for the assessment of VO2max.

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David C. Nieman, Francesca Ferrara, Alessandra Pecorelli, Brittany Woodby, Andrew T. Hoyle, Andrew Simonson and Giuseppe Valacchi

Inflammasomes are multiprotein signaling platforms of the innate immune system that detect markers of physiological stress and promote the maturation of caspase-1 and interleukin 1 beta (IL-1β), IL-18, and gasdermin D. This randomized, cross-over trial investigated the influence of 2-week mixed flavonoid (FLAV) versus placebo (PL) supplementation on inflammasome activation and IL-1β and IL-18 production after 75-km cycling in 22 cyclists (42 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr postexercise (176 ± 5.4 min, 73.4 ± 2.0 %VO2max). The supplement (678 mg FLAVs) included quercetin, green tea catechins, and bilberry anthocyanins. The pattern of change in the plasma levels of the inflammasome adaptor oligomer ASC (apoptosis-associated speck-like protein containing caspase recruitment domain) was different between the FLAV and PL trials, with the FLAV ASC levels 52% lower (Cohen’s d = 1.06) than PL immediately following 75-km cycling (interaction effect, p = .012). The plasma IL-1β levels in FLAV were significantly lower than PL (23–42%; Cohen’s d = 0.293–0.644) throughout 21 hr of recovery (interaction effect, p = .004). The change in plasma gasdermin D levels were lower immediately postexercise in FLAV versus PL (15% contrast, p = .023; Cohen’s d = 0.450). The patterns of change in plasma IL-18 and IL-37 did not differ between the FLAV and PL trials (interaction effects, p = .388, .716, respectively). These data indicate that 2-week FLAV ingestion mitigated inflammasome activation, with a corresponding decrease in IL-1β release in cyclists after a 75-km cycling time trial. The data from this study support the strategy of ingesting high amounts of FLAV to mitigate postexercise inflammation.

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Marco J. Konings and Florentina J. Hettinga

Purpose: The behavior of an opponent has been shown to alter pacing and performance. To advance our understanding of the impact of perceptual stimuli such as an opponent on pacing and performance, this study examined the effect of a preexercise cycling protocol on exercise regulation with and without an opponent. Methods: Twelve trained cyclists performed 4 experimental, self-paced 4-km time-trial conditions on an advanced cycle ergometer in a randomized, counterbalanced order. Participants started the time trial in rested state (RS) or performed a 10-min cycling protocol at 67% peak power output (CP) before the time trial. During the time trials, participants had to ride alone (NO) or against a virtual opponent (OP). The experimental conditions were (1) RS-NO, (2) RS-OP, (3) CP-NO, and (4) CP-OP. Repeated-measures analyses of variance (P < .05) were used to examine differences in pacing and performance in terms of power output. Results: A faster pace was adopted in the first kilometer during RS-OP (318 [72] W) compared with RS-NO (291 [81] W; P = .03), leading to an improved finishing time during RS-OP compared with RS-NO (P = .046). No differences in either pacing or performance were found between CP-NO and CP-OP. Conclusions: The evoked response by the opponent to adopt a faster initial pace in the 4-km time trial disappeared when cyclists had to perform a preceding cycling protocol. The outcomes of this study highlight that perceived exertion alters the responsiveness to perceptual stimuli of cyclists during competition.

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Danny Lum and Abdul Rashid Aziz

Force–time characteristics obtained during isometric strength tests are significantly correlated to various sporting movements. However, data on the relationship between isometric force–time characteristics and sprint kayaking performance are lacking in the literature. Purpose: The purpose of the study was, therefore, to investigate the relationship between sprint kayaking performance with ergometer performance and measures from 3 isometric strength tests: isometric squat, isometric bench press, and isometric prone bench pull. Methods: A total of 23 sprint kayaking athletes performed all 3 tests, at 90° and 120° knee angles for isometric squat and at elbow angles for isometric bench press and isometric prone bench pull, and a 200-m sprint on-water to attain the fastest time-to-completion (OWTT) possible and on a kayak ergometer to attain the highest mean power (LABTT) possible. Results: There was a significant inverse correlation between OWTT and LABTT (r = −.90, P < .001). The peak forces achieved from all isometric strength tests were significantly correlated with time-to-completion for OWTT and mean power for LABTT (r = −.44 to −.88, P < .05 and .47 to .80, P < .05, respectively). OWTT was significantly correlated with the peak rate of force development during all isometric tests except for the isometric squat at a 120° knee angle (r = −.47 to −.62, P < .05). LABTT was significantly correlated with peak rate of force development from the isometric bench press and isometric prone bench pull (r = .64–.86, P < .01). Conclusion: Based on the observed strong correlations, the mean power attained during LABTT is a good predictor of OWTT time-to-completion. Furthermore, upper- and lower-body maximum strength and peak rate of force development are equally important for on-water and ergometer sprint kayaking performance.

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Alex S. Ribeiro, Ademar Avelar, Witalo Kassiano, João Pedro Nunes, Brad J. Schoenfeld, Andreo F. Aguiar, Michele C.C. Trindade, Analiza M. Silva, Luís B. Sardinha and Edilson S. Cyrino

The authors aimed to compare the effects of creatine (Cr) supplementation combined with resistance training on skeletal muscle mass (SMM), total body water, intracellular water (ICW), and extracellular water (ECW) in resistance-trained men as well as to determine whether the SMM/ICW ratio changes in response to the use of this ergogenic aid. Twenty-seven resistance-trained men received either Cr (n = 14) or placebo (n = 13) over 8 weeks. During the same period, subjects performed two split resistance training routines four times per week. SMM was estimated from appendicular lean soft tissue assessed by dual-energy X-ray absorptiometry. Total body water, ICW, and ECW were determined by spectral bioelectrical impedance. Both groups showed improvements (p < .05) in SMM, total body water, and ICW, with greater values observed for the Cr group compared with placebo. ECW increased similarly in both groups (p < .05). The SMM/ICW ratio did not change in either group (p > .05), whereas the SMM/ECW ratio decreased only in the Cr group (p < .05). A positive correlation was observed (p < .05) between SMM and ICW changes (r = .71). The authors’ results suggest that the increase in muscle mass induced by Cr combined with resistance training occurs without alteration of the ratio of ICW to SMM in resistance-trained men.