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Margot Callewaert, Stefan Geerts, Evert Lataire, Jan Boone, Marc Vantorre and Jan Bourgois

Purpose:

To develop a sailing ergometer that accurately simulates upwind sailing exercise.

Methods:

A sailing ergometer that measures roll moment accompanied by a biofeedback system that allows imposing a certain quasi-isometric upwind sailing protocol (ie, 18 bouts of 90-s hiking at constantly varying hiking intensity interspersed with 10 s to tack) was developed. Ten male high-level Laser sailors performed an incremental cycling test (ICT; ie, step protocol at 80 W + 40 W/3 min) and an upwind sailing test (UST). During both, heart rate (HR), oxygen uptake (VO2), ventilation (VE), respiratory-exchange ratio, and rating of perceived exertion were measured. During UST, also the difference between the required and produced hiking moment (HM) was calculated as error score (ES). HR, VO2, and VE were calculated relative to their peak values determined during ICT. After UST, the subjects were questioned about their opinion on the resemblance between this UST and real-time upwind sailing.

Results:

An average HM of 89.0% ± 2.2% HMmax and an average ES of 4.1% ± 1.8% HMmax were found. Mean HR, VO2, and VE were, respectively, 80% ± 4% HRpeak, 39.5% ± 4.5% VO2peak, and 30.3% ± 3.7% VEpeak. Both HM and cardiorespiratory values appear to be largely comparable to literature reports during on-water upwind sailing. Moreover, the subjects gave the upwind sailing ergometer a positive resemblance score.

Conclusions:

Results suggest that this ergometer accurately simulates on-water upwind sailing exercise. As such, this ergometer could be a great help in performance diagnostics and training follow-up.

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Michael Wilkinson, Damon Leedale-Brown and Edward M. Winter

Purpose:

We examined the reproducibility of performance and physiological responses on a squash-specific incremental test.

Methods:

Eight trained squash players habituated to procedures with two prior visits performed an incremental squash test to volitional exhaustion on two occasions 7 days apart. Breath-by-breath oxygen uptake ( Vo2) and heart rate were determined continuously using a portable telemetric system. Blood lactate concentration at the end of 4-min stages was assessed to determine lactate threshold. Once threshold was determined, test speed was increased every minute until volitional exhaustion for assessment of maximal oxygen uptake (Vo2max), maximum heart rate (HRmax), and performance time. Economy was taken as the 60-s mean of Vo2 in the final minute of the fourth stage (below lactate threshold for all participants). Typical error of measurement (TEM) with associated 90% confidence intervals, limits of agreement, paired sample t tests, and least products regression were used to assess the reproducibility of scores.

Results:

Performance time (TEM 27 s, 4%, 90% CI 19 to 49 s) Vo2max (TEM 2.4 mL·kg−1·min−1, 4.7%, 90% CI 1.7 to 4.3 mL·kg−1·min−1), maximum heart rate (TEM 2 beats·min−1, 1.3%, 90% CI 2 to 4 beats·min−1), and economy (TEM 1.6 mL·kg−1·min−1, 4.1%, 90% CI 1.1 to 2.8 mL·kg−1·min−1) were reproducible.

Conclusions:

The results suggest that endurance performance and physiological responses to a squash-specific fitness test are reproducible.

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Moritz Schumann, Javier Botella, Laura Karavirta and Keijo Häkkinen

Purpose:

To compare the effects of a standardized endurance-training program with individualized endurance training modified based on the cumulative training load provided by the Polar training-load feature.

Methods:

After 12 wk of similar training, 24 recreationally endurance-trained men were matched to a training-load-guided (TL, n = 10) or standardized (ST, n = 14) group and continued training for 12 wk. In TL, training sessions were individually chosen daily based on an estimated cumulative training load, whereas in ST the training was standardized with 4–6 sessions/wk. Endurance performance (shortest 1000-m running time during an incremental field test of 6 × 1000 m) and heart-rate variability (HRV) were measured every 4 wk, and maximal oxygen consumption (VO2max) was measured during an incremental treadmill test every 12 wk.

Results:

During weeks 1–12, similar changes in VO2max and 1000-m time were observed in TL (+7% ± 4%, P = .004 and –6% ± 4%, P = .069) and ST (+5% ± 7%, P = .019 and –8% ± 5%, P < .001). During wk 13–24, VO2max statistically increased in ST only (3% ± 4%, P = .034). The 1000-m time decreased in TL during wk 13–24 (–9% ± 5%, P = .011), but in ST only during wk 13–20 (–3% ± 2%, P = .003). The overall changes in VO2max and 1000-m time during wk 0–24 were similar in TL (+7% ± 4%, P = .001 and –9% ± 5%, P = .011) and ST (+10% ± 7%, P < .001 and –13% ± 5%, P < .001). No between-groups differences in total training volume and frequency were observed. HRV remained statistically unaltered in both groups.

Conclusions:

The main finding was that training performed according to the cumulative training load led to improvements in endurance performance similar to those with standardized endurance training in recreational endurance runners.

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Andy Galbraith, James Hopker, Marco Cardinale, Brian Cunniffe and Louis Passfield

Purpose:

To examine the training and concomitant changes in laboratory- and field-test performance of highly trained endurance runners.

Methods:

Fourteen highly trained male endurance runners (mean ± SD maximal oxygen uptake [VO2max] 69.8 ± 6.3 mL · kg−1 · min−1) completed this 1-y training study commencing in April. During the study the runners undertook 5 laboratory tests of VO2max, lactate threshold (LT), and running economy and 9 field tests to determine critical speed (CS) and the modeled maximum distance performed above CS (D′). The data for different periods of the year were compared using repeated-measures ANOVA. The influence of training on laboratory- and field-test changes was analyzed by multiple regression.

Results:

Total training distance varied during the year and was lower in May–July (333 ± 206 km, P = .01) and July–August (339 ± 206 km, P = .02) than in the subsequent January–February period (474 ± 188 km). VO2max increased from the April baseline (4.7 ± 0.4 L/min) in October and January periods (5.0 ± 0.4 L/min, P ≤ .01). Other laboratory measures did not change. Runners’ CS was lowest in August (4.90 ± 0.32 m/s) and highest in February (4.99 ± 0.30 m/s, P = .02). Total training distance and the percentage of training time spent above LT velocity explained 33% of the variation in CS.

Conclusion:

Highly trained endurance runners achieve small but significant changes in VO2max and CS in a year. Increases in training distance and time above LT velocity were related to increases in CS.

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Maria Konstantaki, Edward Winter and Ian Swaine

Context:

Forward propulsion in freestyle swimming is predominantly achieved through arm action. Few studies have assessed the effects of arm training on arm power and swimming performance, yet there have not been any investigations on the effects of arms-only swimming training on swimming performance and physiological responses to arm exercise.

Purpose:

To investigate the changes in arms-only and full-stroke swimming performance, movement economy and aerobic power after an arms-only swimming training program.

Methods:

Fifteen male county level swimmers were assigned either to an experimental (ES, n = 8) or control group (CS, n = 7). For six weeks ES performed arms-only freestyle swimming exercises for 20% of their weekly training distance three times per week, whereas CS performed their usual swimming training. Before and after the training program, both groups performed a) two time trials, 186 m using arms-only (186ARMS) and 372 m using full-stroke (372FULL) freestyle swimming, and b) an incremental arm-pulling exercise test. The time to complete the trials was recorded. Peak oxygen uptake (VO2peak), peak exercise intensity (EIpeak) submaximal oxygen uptake at 60 W (VO2−60) and exercise intensity at ventilatory threshold (VTW) were determined from the exercise test.

Results:

After training, ES had improved in 186ARMS (−14.2 ± 3.6%, P = .03), VO2−60 (−22.5 ± 2.3%, P = .04), EIpeak (+17.8 ± 4.2%, P = .03), and VTW (+18.9 ± 2.3%, P = .02), but not in VO2peak (P = .09) or in 372FULL (P = .07). None of the measures changed in CS (P > .05).

Conclusion:

Arms-only swimming training at 20% of the weekly training distance is an effective method to improve arm conditioning during the preparatory phase of the annual training cycle.

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Judith Allgrove, Emily Farrell, Michael Gleeson, Gary Williamson and Karen Cooper

This study investigated the effects of regular consumption of dark chocolate (DC), rich in cocoa polyphenols, on plasma metabolites, hormones, and markers of oxidative stress after prolonged exhaustive exercise. Twenty active men cycled at 60% maximal oxygen uptake (VO2max) for 1.5 hr, with the intensity increased to 90% VO2max for a 30-s period every 10 min, followed by a ride to exhaustion at 90% VO2max. In the 2 wk before exercise participants consumed 40 g of DC or an isocarbohydrate-fat control cocoa liquor–free chocolate (CON) twice daily and once 2 hr before exercise in a randomized, counterbalanced, crossover design. Venous blood samples were taken immediately before exercise, postexercise (fixed duration), postexhaustion, and after 1 hr of recovery. F2-isoprostanes were significantly lower (post hoc tests: p < .001) at exhaustion and after 1 hr of recovery with DC. Oxidized low-density lipoproteins were significantly lower with DC (p < .001) both before and after exercise and at exhaustion. DC was also associated with ~21% greater rises in free fatty acids during exercise (main effect: p < .05). Changes in circulating glucose, insulin, glucagon, cortisol, and interleukin (IL)-6, IL-10, and IL-1ra were unaffected by treatment. Time to exhaustion at 90% VO2max was not significantly different between trials (398 ± 204 and 374 ± 194 s for DC and CON, respectively). These results suggest that regular DC intake is associated with reduced oxidative-stress markers and increased mobilization of free fatty acids after exercise but has no observed effect on exercise performance.

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Martin Buchheit, Bachar Haydar, Karim Hader, Pierre Ufland and Said Ahmaidi

Purpose:

To examine physiological responses to submaximal feld running with changes of direction (COD), and to compare two approaches to assess running economy (RE) with COD, ie, during square-wave (SW) and incremental (INC) exercises.

Methods:

Ten male team-sport athletes performed, in straight-line or over 20 m shuttles, one maximal INC and four submaximal SW (45, 60, 75 and 90% of the velocity associated with maximal pulmonary O2 uptake [vVO2pmax]). Pulmonary (VO2p) and gastrocnemius (VO2m) O2 uptake were computed for all tests. For both running mode, RE was estimated as the O2 cost per kilogram of bodyweight, per meter of running during all SW and INC.

Results:

Compared with straight-line runs, shuttle runs were associated with higher VO2p (eg, 33 ± 6 vs 37 ± 5 mL O2·min–1·kg–1 at 60%, P < .01) and VO2m (eg, 1.1 ± 0.5 vs 1.3 ± 0.8 mL O2·min–1·100 g–1 at 60%, P = .18, Cohen’s d = 0.32). With COD, RE was impaired during SW (0.26 ± 0.02 vs 0.24 ± 0.03 mL O2·kg–1·m–1, P < .01) and INC (0.23 ± 0.04 vs 0.16 ± 0.03 mL O2·kg–1·m–1, P < .001). For both SW and INC tests, the changes in RE with COD were related to height (eg, r = .56 [90%CL, 0.01;0.85] for SW) and weekly training/competitive volume (eg, r = –0.58 [–0.86;–0.04] for SW). For both running modes, RE calculated from INC was better than that from SW (both P < .001).

Conclusion:

Although RE is impaired during feld running with COD, team-sport players of shorter stature and/or presenting greater training/competitive volumes may present a lower RE deterioration with COD. Present results do not support the use of INC to assess RE in the feld, irrespective of running mode.

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Gianluca Vernillo, Alfredo Brighenti, Eloisa Limonta, Pietro Trabucchi, Davide Malatesta, Grégoire P. Millet and Federico Schena

Purpose:

To quantify changes in skeletal-muscle oxygenation and pulmonary O2 uptake (V̇O2) after an extreme ultratrail running bout.

Methods:

Before (PRE) and after (POST) the race (330-km, 24000 D±), profiles of vastus lateralis muscle oxygenation (ie, oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb], and tissue oxygenation index [TOI]) and V̇O2 were determined in 14 athletes (EXP) and 12 control adults (CON) during two 4-min constant-load cycling bouts at power outputs of 1 (p1) and 1.5 (p1.5) W/kg performed in randomized order.

Results:

At POST, normalized [HHb] values increased (p1, +38.0%; p1.5, +27.9%; P < .05), while normalized [O2Hb] (p1, –20.4%; p1.5, –14.4%; P < .05) and TOI (p1, –17.0%; p1.5, –17.7%; P < .05) decreased in EXP. V̇O2 values were similar (P > 0.05). An “overshoot“ in normalized [HHb]:V̇O2 was observed, although the increase was significant only during p1.5 (+58.7%, P = .003). No difference in the aforementioned variables was noted in CON (P > .05).

Conclusions:

The concentric and, particularly, the eccentric loads characterizing this extreme ultratrail-running bout may have led to variations in muscle structure and function, increasing the local muscle deoxygenation profile and the imbalance between O2 delivery to working muscles and muscle O2 consumption. This highlights the importance of incorporating graded training, particularly downhill bouts, to reduce the negative influence of concentric and severe eccentric loads to the microcirculatory function and to enhance the ability of runners to sustain such loading.

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Andrew D. Williams, Isaac Selva Raj, Kristie L. Stucas, James W. Fell, Diana Dickenson and John R. Gregory

Objectives:

Uncoupled cycling cranks are designed to remove the ability of one leg to assist the other during the cycling action. It has been suggested that training with this type of crank can increase mechanical efficiency. However, whether these improvements can confer performance enhancement in already well-trained cyclists has not been reported.

Method:

Fourteen well-trained cyclists (13 males, 1 female; 32.4 ± 8.8 y; 74.5 ± 10.3 kg; Vo2max 60.6 ± 5.5 mL·kg−1·min−1; mean ± SD) participated in this study. Participants were randomized to training on a stationary bicycle using either an uncoupled (n = 7) or traditional crank (n = 7) system. Training involved 1-h sessions, 3 days per week for 6 weeks, and at a heart rate equivalent to 70% of peak power output (PPO) substituted into the training schedule in place of other training. Vo2max, lactate threshold, gross efficiency, and cycling performance were measured before and following the training intervention. Pre- and post testing was conducted using traditional cranks.

Results:

No differences were observed between the groups for changes in Vo2max, lactate threshold, gross efficiency, or average power maintained during a 30-minute time trial.

Conclusion:

Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.

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Laura Lewis Frank, Janine T. Baer, Charles P. Lambert and Mark L. Anderson

The effect of fungal carbohydrases (Carbogen™ [C]) consumed with a meal replacement bar (MBR) on glucose metabolism and exercise performance was determined in 5 male competitive cyclists. After a 12-hour fast, subjects performed two 60-min cycling bouts at 80% V̇O2max followed by a time-to-exhaustion (TE) ride at 100% V̇O2max. One hour prior to each cycling bout, subjects ingested a MRB + 160-mg C or 160-mg CaCO3 placebo (PL) in a double-blind, counterbalanced fashion. Blood was drawn for determination of glucose, insulin, and lactate at: fasting, 1 hour post-feeding, minutes 30 and 60 of exercise, and after TE. Two-way ANOVA revealed a significant (p < .05) treatment and time effect for glucose, with C being higher than PL. Interaction effects were ob-· served for insulin and lactate. An increase in TE (min) at 100% V̇O2max was observed in the C versus PL trial (6.3 ± 3.4 vs. 4.4 ± 2.9, p < .001). A MRB+C may benefit cyclists due to increased BG and improved exercise performance.