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Purpose: To investigate whether oxygen-uptake (...) kinetics and simulated 4-km cycling performance are synergistically improved by prior "priming" exercise and an all-out starting strategy. Methods: Nine men completed 4 target work trials (114 ± 17 kJ) to assess ... kinetics and cycling performance in a repeated-measures, crossover experimental design. Trials were initiated with either a 12-s all-out start or a self-selected start and preceded by prior severe-intensity (70%Δ) priming exercise or no priming exercise. Results: The ... mean response time (MRT) was lower (indicative of faster ... kinetics) in the all-out primed condition (20 ± 6 s) than in the all-out unprimed (23 ± 6 s), self-paced-unprimed (42 ± 13 s), and self-paced-primed (42 ± 11 s) trials (P < .05), with the ... MRT also lower in the all-out unprimed than the self-paced unprimed and self-paced primed trials (P < .05). Trial-completion time was shorter (performance was enhanced) in the all-out primed trial (402 ± 14 s) than in the all-out unprimed (408 ± 14 s), self-paced unprimed (411 ± 16 s), and self-paced primed (411 ± 19 s) trials (P < .05), with no differences between the latter 3 trials. Conclusions: The findings from this study suggest that combining severe-intensity priming exercise with a short-duration all-out starting strategy can expedite the adjustment of ... and lower completion time during a cycling performance trial to a greater extent than either intervention administered independently. These results might have implications for optimizing performance in short-duration high-intensity competitive events such as a 4-km cycling time trial. [ABSTRACT FROM AUTHOR]

Dietary nitrate (N[O.sup.-.sub.3]) supplementation with beetroot juice (BR) over 4-6 days has been shown to reduce the [O.sub.2] cost of submaximal exercise and to improve exercise tolerance. However, it is not known whether shorter (or longer) periods of supplementation have similar (or greater) effects. We therefore investigated the effects of acute and chronic N[O.sup.-.sub.3] supplementation on resting blood pressure (BP) and the physiological responses to moderate-intensity exercise and ramp incremental cycle exercise in eight healthy subjects. Following baseline tests, the subjects were assigned in a balanced crossover design to receive BR (0.5 l/day; 5.2 mmol of N[O.sup.-.sub.3]/day) and placebo (PL; 0.5 l/day low-calorie juice cordial) treatments. The exercise protocol (two moderate-intensity step tests followed by a ramp test) was repeated 2.5 h following first ingestion (0.5 liter) and after 5 and 15 days of BR and PL. Plasma nitrite concentration (baseline: 454 [+ or -] 81 nM) was significantly elevated (+39% at 2.5 h postingestion; +25% at 5 days; +46% at 15 days; P < 0.05) and systolic and diastolic BP (baseline: 127 [+ or -] 6 and 72 [+ or -] 5 mmHg, respectively) were reduced by ~4% throughout the BR supplementation period (P < 0.05). Compared with PL, the steady-state [??][O.sub.2] during moderate exercise was reduced by ~4% after 2.5 h and remained similarly reduced after 5 and 15 days of BR (P < 0.05). The ramp test peak power and the work rate at the gas exchange threshold (baseline: 322 [+ or -] 67 W and 89 [+ or -] 15 W, respectively) were elevated after 15 days of BR (331 [+ or -] 68 W and 105 [+ or -] 28 W; P < 0.05) but not PL (323 [+ or -] 68 W and 84 [+ or -] 18 W). These results indicate that dietary N[O.sup.-.sub.3] supplementation acutely reduces BP and the [O.sub.2] cost of submaximal exercise and that these effects are maintained for at least 15 days if supplementation is continued. beetroot juice; [O.sub.2] uptake; ramp exercise; performance; nitric oxide doi: 10.1152/ajpregu.00206.2010.

Purpose: To assess whether combining prior "priming" exercise with an all-out pacing strategy is more effective at improving oxygen-uptake (...O2) kinetics and cycling performance than either intervention administered independently. Methods: Nine men completed target-work cycling performance trials using a self-paced or all-out pacing strategy with or without prior severe-intensity (70%Δ) priming exercise. Breath-by-breath pulmonary VO2 and cycling power output were measured during all trials. Results: Compared with the self-paced unprimed control trial (22 ± 5 s), the VO2 mean response time (MRT) was shorter (...O2 kinetics were faster) with all-out pacing (17 ± 4 s) and priming (17 ± 3 s), with the lowest ...O2 MRT observed when all-out pacing and priming were combined (15 ± 4 s) (P < .05). However, total O2 consumed and end-exercise ...O2 were only higher than the control condition in the primed trials (P < .05). Similarly, cycling performance was improved compared with control (98 ±11 s) in the self-paced primed (93 ± 8 s) and all-out primed (92 ± 8 s) trials (P < .05) but not the all-out unprimed trial (97 ± 5 s; P > .05). Conclusions: These findings suggest that combining an all-out start with severe-intensity priming exercise additively improves VO2 MRT but not total O2 consumption and cycling performance since these were improved by a similar magnitude in both primed trials relative to the self-paced unprimed control condition. Therefore, these results support the use of priming exercise as a precompetition intervention to improve oxidative metabolism and performance during short-duration high-intensity cycling exercise, independent of the pacing strategy adopted. [ABSTRACT FROM AUTHOR]

In the absence of a ⩒o2-work-rate plateau, debate continues regarding the best way to verify that the peak ⩒o2 achieved during incremental exercise (⩒o2peak) is the "true ⩒o2max." Oft-used "secondary criteria" have been questioned in conjunction with the contention that a severe-intensity constant-work-rate "verification bout" should be considered the "gold standard." The purpose of this study was to compare the ⩒o2peak during ramp incremental cycling (RAMP-INC) by a heterogeneous (with respect to body composition and sex) cohort of sedentary individuals with the ⩒o2peak during severe-intensity constant-work-rate cycling (CWR) performed after RAMP-INC at the highest work rate achieved. A secondary purpose was to determine the degree to which traditional and newly-proposed age-dependent secondary criteria (RER, HR) identified RAMP-INC which CWR confirmed were characterized by a submaximal ⩒o2peak. Thirty-five healthy male (n = 19: 33.4 ± 6.3 yrs) and female (26.8 ± 3.6 yrs) sedentary participants performed RAMP-INC followed by CWR. The ⩒o2peak values from the two tests were correlated (r = 0.96; p < 0.01; mean CV = 24%); however, ⩒o2peak for CWR was significantly greater (29.6 ± 7.2 v. 28.6 ± 6.8 mL∙min-1∙kg-1; p < 0.01) with a mean bias of 0.98 mL∙min-1∙kg-1 (z = -2.9, p < 0.01). Both traditional and newly-proposed criterion values for RER were achieved during RAMP-INC by 33 of 35 participants (including 21 of 23 who registered a higher ⩒o2peak on CWR). The traditional HR criterion value was achieved on only seven tests (three of which were confirmed to be characterized by a submaximal ⩒o2peak) while use of less stringent newly-proposed criteria resulted in acceptance of an additional seven tests of which five were confirmed to be submaximal. Severe-intensity CWR to limit of tolerance indicates that RAMP-INC underestimates ⩒o2max in sedentary individuals and both traditional and newly-proposed secondary criteria are ineffective for identifying such tests. [ABSTRACT FROM AUTHOR]

This study determined the sustainability and safety of a linearly-progressive, non-periodized resistance training protocol for beginners by having the subjects attempt to complete 12 wks of training comprising the squat exercise. Fifty-eight subjects with no previous history of resistance training participated in this study. The main finding from this feasibility study was that 60% of the subjects were able to linearly progress their load on the squat during each session of a 12-wk intervention. Our findings show that it is feasible for a majority of young strength-training novices to complete 12 wks of non-periodized resistance training involving the squat exercise performed with a load that is linearly progressed during every workout session. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether a tethered-swimming incremental test comprising small increases in resistive force applied every 60 seconds could delineate the isocapnic region during rapidly-incremented exercise. Sixteen competitive swimmers (male, n = 11; female, n = 5) performed: (a) a test to determine highest force during 30 seconds of all-out tethered swimming (Favg) and the ΔF, which represented the difference between Favg and the force required to maintain body alignment (Fbase), and (b) an incremental test beginning with 60 seconds of tethered swimming against a load that exceeded Fbase by 30% of ΔF followed by increments of 5% of ΔF every 60 seconds. This incremental test was continued until the limit of tolerance with pulmonary gas exchange (rates of oxygen uptake and carbon dioxide production) and ventilatory (rate of minute ventilation) data collected breath by breath. These data were subsequently analyzed to determine whether two breakpoints defining the isocapnic region (i.e., gas exchange threshold and respiratory compensation point) were present. We also determined the peak rate of O2 uptake and exercise economy during the incremental test. The gas exchange threshold and respiratory compensation point were observed for each test such that the associated metabolic rates, which bound the heavy-intensity domain during constant-work-rate exercise, could be determined. Significant correlations (Spearman's) were observed for exercise economy along with (a) peak rate of oxygen uptake (ρ = .562; p < 0.025), and (b) metabolic rate at gas exchange threshold (ρ = -.759; p < 0.005). A rapidly-incremented tethered-swimming test allows for determination of the metabolic rates that define zones for domain-specific constant-work-rate training. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine which of two Olympic Weightlifting start positions would yield the more efficient movement pattern. We compared the traditional Olympic lifting starting position with an experimental alignment that has been proposed to reduce horizontal displacement of the barbell. It was hypothesized that the experimental alignment would produce a barbell path more closely approaching linear movement. Ten subjects completed a series of cleans and snatches under both alignment conditions. The experimental alignment resulted in significant reductions in horizontal displacement (~40.3 mm and ~31.9 mm for snatch and clean, respectively; P<0.05). The experimental alignment did not result in a significant difference in peak power (snatch, ~2.2%; clean, ~2.6%). The findings indicate that experimental alignment proposed in this study reduced barbell horizontal displacement during the snatch and clean. Further research is needed to determine if there is an influence of the starting position on power output during these lifts. [ABSTRACT FROM AUTHOR]