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Julia Kathrin Baumgart and Øyvind Sandbakk

Purpose:

To investigate on-ice repeated-sprint and sports-specific-technique abilities and the relationships to aerobic and anaerobic off-ice capacities in world-class ice sledge hockey players.

Methods:

Twelve Norwegian national team players performed 8 repeated maximal 30-m sprints and a sports-specific-technique test while upper-body poling on ice, followed by 4 maximal upper-body strength tests and 8-s peak power and 3-min peak aerobic-capacity (VO2peak) tests while ergometer poling.

Results:

The fastest 30-m sprint time was 6.5 ± 0.4 s, the fastest initial 10-m split-time 2.9 ± 0.2 s, and the corresponding power output 212 ± 37 W. Average 30-m time during the 8 repeated sprints was 6.7 ± 0.4 s, and the sprint-time decrement was 4.3% ± 1.8%. Time to execute the sport-specific-technique test was 25.6 ± 2.7 s. Averaged 1-repetition-maximum strength of the 4 exercises correlated with the fastest 30-m sprint time (r = –.77), the fastest initial 10-m split time (r = –.72), the corresponding power output (r = .67), and the average 30-m sprint time (r = –.84) (all P < .05). Peak power of the 8-s ergometer sprint test correlated with the highest initial 10-m power (r = .83, P < .01) and the average 30-m sprint time (r = –.68, P < .05). Average 3-min ergometer power (r = –.86, P < .01) and VO2peak (r = –.67, P < .05) correlated with the sprint-time decrement. All off-ice variables except VO2peak correlated with technique-test time (r = –.58 to .73, all P < .05).

Conclusion:

Maximal strength and power are associated with the ability to sprint fast and rapid execution of a technically complex test, whereas mode-specific endurance capacity is particularly important for maintenance of sprint ability in ice sledge hockey.

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Manfred Lamprecht, Peter Hofmann, Joachim F. Greilberger and Guenther Schwaberger

Purpose:

To assess the effects of an encapsulated antioxidant concentrate (EAC) and exercise on lipid peroxidation (LIPOX) and the plasma antioxidant enzyme glutathione peroxidase (Pl-GPx).

Methods:

Eight trained male cyclists (VO2max > 55 ml · kg−1 · min−1) participated in this randomized, placebo-controlled, double-blinded, crossover study and undertook 4 cycle-ergometer bouts: 2 moderate exercise bouts over 90 min at 45% of individual VO2max and 2 strenuous exercise bouts at 75% of individual VO2max for 30 min. The first 2 exercise tests—1 moderate and 1 strenuous—were conducted after 4 weeks wash-out and after 12 and 14 days of EAC (107 IU vitamin E, 450 mg vitamin C, 36 mg β-carotene, 100 μg selenium) or placebo treatment. After another 4 weeks wash-out, participants were given the opposite capsule treatment and repeated the 2 exercise tests. Physical exercise training was equal across the whole study period, and nutrition was standardized by a menu plan the week before the tests. Blood was collected before exercise, immediately postexercise, and 30 min and 60 min after each test. Plasma samples were analyzed for LIPOX marker malondialdehyde (MDA) and the antioxidant enzyme pl-GPx.

Results:

MDA concentrations were significantly increased after EAC supplementation at rest before exercise and after moderate exercise (p < .05). MDA concentrations showed no differences between treatments after strenuous exercise (p > .1). Pl-GPx concentrations decreased at all time points of measurement after EAC treatment (p < .05).

Conclusions:

The EAC induced an increase of LIPOX as indicated by MDA and decreased pl-GPx concentrations pre- and postexercise.

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Brian J. Martin, Rachel B. Tan, Jenna B. Gillen, Michael E. Percival and Martin J. Gibala

Supplementation with green tea extract (GTE) in animals has been reported to induce numerous metabolic adaptations including increased fat oxidation during exercise and improved performance. However, data regarding the metabolic and physiological effects of GTE during exercise in humans are limited and equivocal.

Purpose:

To examine the effects of short-term GTE treatment on resting energy expenditure (REE), wholebody substrate utilization during exercise and time trial performance.

Methods:

Fifteen active men (24 ± 3 y; VO2peak = 48 ± 7 ml·kg·min−1; BMI = 26 ± 3 kg·m2(–1)) ingested GTE (3x per day = 1,000 mg/d) or placebo (PLA) for 2 day in a double-blind, crossover design (each separated by a 1 week wash-out period). REE was assessed in the fasted state. Subjects then ingested a standardized breakfast (~5.0 kcal·kg-1) and 90 min later performed a 60 min cycling bout at an intensity corresponding to individual maximal fat oxidation (44 ± 11% VO2peak), followed by a 250 kJ TT.

Results:

REE, whole-body oxygen consumption (VO2) and substrate oxidation rates during steady-state exercise were not different between treatments. However, mean heart rate (HR) was lower in GTE vs. PLA (115 ± 16 vs. 118 ± 17 beats·min−1; main effect, p = .049). Mixed venous blood [glycerol] was higher during rest and exercise after GTE vs. PLA (p = .006, main effect for treatment) but glucose, insulin and free-fatty acids were not different. Subsequent time trial performance was not different between treatments (GTE = 25:38 ± 5:32 vs. PLA = 26:08 ± 8:13 min; p = .75).

Conclusion:

GTE had minimal effects on whole-body substrate metabolism but significantly increased plasma glycerol and lowered heart rate during steady-state exercise, suggesting a potential increase in lipolysis and a cardiovascular effect that warrants further investigation.

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Joelle Leonie Flueck, Martina Lienert, Fabienne Schaufelberger, Jörg Krebs and Claudio Perret

The aim of our study was to investigate the effect of caffeine supplementation on 3-min all-out arm crank exercise performance in paraplegic (P) and tetraplegic (T) compared with able-bodied (AB) participants. A placebo-controlled, randomized, crossover, and double-blind study design was chosen to investigate the differences between caffeine (CAF) and placebo (PLC). In total, 34 healthy, trained participants were tested. Seventeen were AB (median [minimum; maximum] VO2peak: 33.9 mL/min/kg [23.6; 57.6]), 10 were P (VO2peak: 34.4 mL/min/kg [19.5; 48.8]), and 7 were T (VO2peak: 13.6 mL/min/kg [8.6; 16.3]). All participants performed two 3-min all-out tests on an arm crank ergometer following the ingestion of either PLC or CAF. Power output parameters, plasma caffeine (PC), epinephrine (EPI), and norepinephrine (NOR) concentrations were assessed. CAF significantly increased average power over the first 30 s (p = .028) and 60 s (p = .005) in P, but not in T (p = .61; p = .87) nor in AB (p = .25; p = .44). Peak power was increased in the CAF trial in AB (+46 W) as well as in P (+21 W) but was not significantly different from PLC (AB: p = .10; P: p = .17). PC significantly increased in all groups (AB: p = .002; P: p = .005; T: p = .018) whereas EPI showed a significant increase only in AB (p = .002) and in P (p = .018). NOR increased significantly in AB (p = .018) but did not increase in the other groups. Caffeine seems to enhance short-duration exercise performance in P. In contrast, T showed a high interindividual variability and overall no ergogenic effect was detected in this group.

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Charles R. Pedlar, Gregory P. Whyte, Richard Burden, Brian Moore, Gill Horgan and Noel Pollock

This case study examines the impact of low serum ferritin (sFe) on physiological assessment measures and performance in a young female 1500-m runner undertaking approximately 95–130 km/wk training. The study spans 4 race seasons and an Olympic Games. During this period, 25 venous blood samples were analyzed for sFe and hemoglobin (Hb); running economy, VO2max, and lactate threshold were measured on 6 occasions separated by 8–10 mo. Training was carefully monitored including 65 monitored treadmill training runs (targeting an intensity associated with the onset of blood lactate accumulation) using blood lactate and heart rate. Performances at competitive track events were recorded. All data were compared longitudinally. Mean sFe was 24.5 ± 7.6 μg/L (range 10–47), appearing to be in gradual decline with the exception of 2 data points (37 and 47 μg/L) after parenteral iron injections before championships, when the lowest values tended to occur, coinciding with peak training volumes. Each season, 1500-m performance improved, from 4:12.8 in year 1 to 4:03.5 in year 4. VO2max (69.8 ± 2.0 mL · kg−1 · min−1) and running economy (%VO2max at a fixed speed of 16 km/h; max 87.8%, min 80.3%) were stable across time and lactate threshold improved (from 14 to 15.5 km/h). Evidence of anemia (Hb <12 g/dL) was absent. These unique data demonstrate that in 1 endurance athlete, performance can continue to improve despite an apparent iron deficiency. Raising training volume may have caused increased iron utilization; however, the effect of this on performance is unknown. Iron injections were effective in raising sFe in the short term but did not appear to affect the long-term pattern.

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Thomas Losnegard and Jostein Hallén

Purpose:

Sprint- (≤1.8 km) and distance-skiing (≥15 km) performance rely heavily on aerobic capacity. However, in sprint skiing, due to the ~20% higher speed, anaerobic capacity contributes significantly. This study aimed to identify the possible anthropometric and physiological differences between elite male sprint and distance skiers.

Methods:

Six sprint and 7 distance international-level cross-country skiers completed testing using the V2 skating technique on a roller-ski treadmill. Measurements included submaximal O2 cost (5°, 3 m/s) and a 1000-m time trial (6°, >3.25 m/s) to assess VO2peak and accumulated oxygen (ΣO2) deficit.

Results:

The groups displayed similar O2 cost during the submaximal load. The sprint skiers had a higher ΣO2 deficit (79.0 ± 11.3 vs 65.7 ± 7.5 mL/kg, P = .03, ES = 1.27) and VO2peak in absolute values (6.6 ± 0.5 vs 6.0 ± 0.5 L/min, P = .04, ES =1.23), while VO2peak relative to body mass was lower than in the distance skiers (76.4 ± 4.4 vs 83.0 ± 3.2 mL · kg−1 · min−1, P = .009, ES = 1.59). The sprint skiers were heavier than the distance skiers (86.6 ± 6.1 vs 71.8 ± 7.2 kg, P = .002, ES = 2.07), taller (186 ± 5 vs 178 ± 7 cm, P = .04, ES = 1.25), and had a higher body-mass index (24.9 ± 0.8 vs 22.5 ± 1.3 kg/m2, P = .003, ES = 2.05).

Conclusion:

The elite male sprint skiers showed different anthropometric and physiological qualities than the distance skiers, with these differences being directly related to body mass.

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Paolo Menaspà, Ermanno Rampinini, Lara Tonetti and Andrea Bosio

Purpose:

To describe the physical fitness of a top-level lower limb amputee (LLA) cyclist and paracycling time-trial (TT) race demands.

Methods:

The 40-y-old male unilateral transfemoral amputee TT World Champion was tested in a laboratory for peak oxygen uptake (VO2peak), ventilatory threshold (VT2), power output (PO), and hemoglobin mass (Hb-mass). Moreover, several measures (eg, PO, heart rate [HR], cadence) were collected during 4 international TT competitions in the same season. The races’ intensity was evaluated as time spent below, at, or above VT2.

Results:

The cyclist (1.73 m, 55.0 kg) had a VO2peak of 3.372 L/min (61.3 mL · kg−1 · min−1). The laboratory peak PO was 315 W (5.7 W/kg). The maximal HR was 208 beats/min, and his Hb-mass was 744 g (13.5 g/kg). The TTs were meanly 18 ± 4.5 km in length, and the mean PO was 248 ± 8 W with a cadence of 92 ± 1 rpm. During the TTs, the cyclist spent 23% ± 9% of total time at VT2, 59% ± 10% below, and 18% ± 5% above this intensity.

Conclusions:

The subject’s relative VO2peak is higher than previously published data on LLA, and surprisingly it is even higher than “good” ACSM normative data for nondisabled people. The intensity of the races was found to be similar to cycling TTs of the same duration in elite female cyclists. These results might be useful to develop specific training schedules and enhance performance of LLA cyclists.

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Lars R. McNaughton, Steve Kenney, Jason Siegler, Adrian W. Midgley, Ric J. Lovell and David J. Bentley

Context:

Recently, superoxygenated-water beverages have emerged as a new purported ergogenic substance.

Purpose:

This study aimed to determine the effects of superoxygenated water on submaximal endurance performance.

Methods:

Eleven active male subjects, VO2max 52.6 ± 4.8 mL · kg−1 · min−1, height 180.0 ± 2.0 cm, weight 76.0 ± 7.0 kg, age 24 ± 1.0 y (mean ± SD), completed a 45-min cycle-ergometry exercise test at 70% of their previously predicted maximal power output with a 10-min rest period, followed by a 15-min time trial (TT). Thirty minutes before the exercise test subjects consumed 15 mL of either superoxygenated water (E) or placebo (P; water mixed with low-chlorine solution). Subjects then completed the test again a week later for the other condition (double-blind, randomized). The physiological variables measured during exercise were VO2, VCO2, respiratory-exchange ratio (RER), VE, PO2, PCO2, blood lactate (bLa–), and heart rate (HR). Mean distance covered and the average power output for the 15-min TT were also measured as performance indicators.

Results:

There were no significant differences in VO2, VCO2, RER, VE, bLa, PO2, and HR (P > .05) during the exercise tests. Neither were there any significant improvements in the total distance covered (P 9.01 ± 0.74 km vs E 8.96 ± 0.68 km, P > .05) or the average power output (P 186.7 ± 35.8 W vs E 179.0 ± 25.9 W, P > .05) during the 15-min TT.

Conclusion:

Based on these results the authors conclude that consuming 15 mL of superoxygenated water does not enhance submaximal or maximal TT cycling performance.

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Martin J. Barwood, Jo Corbett, Christopher R.D. Wagstaff, Dan McVeigh and Richard C. Thelwell

Purpose:

Unpleasant physical sensations during maximal exercise may manifest themselves as negative cognitions that impair performance, alter pacing, and are linked to increased rating of perceived exertion (RPE). This study examined whether motivational self-talk (M-ST) could reduce RPE and change pacing strategy, thereby enhancing 10-km time-trial (TT) cycling performance in contrast to neutral self-talk (N-ST).

Methods:

Fourteen men undertook 4 TTs, TT1–TT4. After TT2, participants were matched into groups based on TT2 completion time and underwent M-ST (n = 7) or N-ST (n = 7) after TT3. Performance, power output, RPE, and oxygen uptake (VO2) were compared across 1-km segments using ANOVA. Confidence intervals (95%CI) were calculated for performance data.

Results:

After TT3 (ie, before intervention), completion times were not different between groups (M-ST, 1120 ± 113 s; N-ST, 1150 ± 110 s). After M-ST, TT4 completion time was faster (1078 ± 96 s); the N-ST remained similar (1165 ± 111 s). The M-ST group achieved this through a higher power output and VO2 in TT4 (6th–10th km). RPE was unchanged. CI data indicated the likely true performance effect lay between 13- and 71-s improvement (TT4 vs TT3).

Conclusion:

M-ST improved endurance performance and enabled a higher power output, whereas N-ST induced no change. The VO2 response matched the increase in power output, yet RPE was unchanged, thereby inferring a perceptual benefit through M-ST. The valence and content of self-talk are important determinants of the efficacy of this intervention. These findings are primarily discussed in the context of the psychobiological model of pacing.

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Dean G. Higham, David B. Pyne, Judith M. Anson and Anthony Eddy

Although the characteristics of 15-a-side rugby union players have been well defined, there is little information on rugby sevens players.

Purpose:

The authors profiled the anthropometric, physiological, and performance qualities of elite-level rugby sevens players and quantified relationships between these characteristics.

Methods:

Eighteen male international rugby sevens players undertook anthropometric (body mass, height, sum of 7 skinfolds, lean-mass index), acceleration and speed (40-m sprint), muscle-power (vertical jump), repeatedsprint- ability (6 × 30-m sprint), and endurance (Yo-Yo Intermittent Recovery test and treadmill VO2max) testing. Associations between measurements were assessed by correlation analysis.

Results:

Rugby sevens players had anthropometric characteristics (body mass 89.7 ± 7.6 kg, height 1.83 ± 0.06 m, sum of 7 skinfolds 52.2 ± 11.5 mm; mean ± SD) similar to those of backs in international 15-player rugby union. Acceleration and speed (40-m sprint 5.11 ± 0.15 s), muscle-power (vertical jump 66 ± 7 cm), and endurance (VO2max 53.8 ± 3.4 mL · kg−1 · min−1 ) qualities were similar to, or better than, those of professional 15-a-side players. Coefficients of variation ranged from 2.5% to 22%. Relative VO2max was largely correlated with Yo-Yo distance (r = .60, .21−.82; 90% confidence interval) and moderately correlated with 40-m sprint time (r = −.46, −.75 to −.02) and repeated-sprint ability (r = −.38, −.72 to .09).

Conclusions:

International rugby sevens players require highly developed speed, power, and endurance to tolerate the demands of competition. The small between-athletes variability of characteristics in rugby sevens players highlights the need for relatively uniform physical and performance standards in contrast with 15-a-side players.