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Filippo Dolci, Andrew E. Kilding, Tania Spiteri, Paola Chivers, Ben Piggott, Andrew Maiorana, and Nicolas H. Hart

Movement economy represents the energetic (or aerobic) efficiency of performing a given task at submaximal intensities, and it is a crucial determinant of endurance performance. 1 To date, movement economy has been mostly assessed during tasks such as in-line running and, for this reason, is

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Nicholas Tam, Ross Tucker, Jordan Santos-Concejero, Danielle Prins, and Robert P. Lamberts

Running economy, defined as the oxygen or energy cost of transport, has been found to be an important and reliable predictor of running performance. 1 The value of running economy as a performance predictor arises because both metabolic and biomechanical aspects contribute to it, and by extension

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Kate M. Luckin-Baldwin, Claire E. Badenhorst, Ashley J. Cripps, Grant J. Landers, Robert J. Merrells, Max K. Bulsara, and Gerard F. Hoyne

Triathlon success is predominantly determined by the athletes’ maximum sustained power or pace during competition and the energy cost associated with maintaining this movement. 1 The energy cost associated with this sustained power or pace is known as the athletes’ economy, defined as the

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Alana Thomson, Kristine Toohey, and Simon Darcy

apply Whaites’ ( 2017 ) political economy framework, which includes aspects of network structures, stakeholders, and processes, to explore the inherent distinctions between the political economies of sport and sport events. Political economy is a paradigm through which resource production and

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Alana Thomson, Kristine Toohey, and Simon Darcy

apply Whaites’ ( 2017 ) political economy framework, which includes aspects of network structures, stakeholders, and processes, to explore the inherent distinctions between the political economies of sport and sport events. Political economy is a paradigm through which resource production and

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Dionne A. Noordhof, Elmy van Tok, Florentine S.J.G.M. Joosten, Florentina J. Hettinga, Marco J.M. Hoozemans, Carl Foster, and Jos J. de Koning

Half the improvement in 1500-m speed-skating world records can be explained by technological innovations and the other half by athletic improvement. It is hypothesized that improved skating economy is accountable for much of the athletic improvement. Purpose: To determine skating economy in contemporary athletes and to evaluate the change in economy over the years. Methods: Contemporary skaters of the Dutch national junior team (n = 8) skated 3 bouts of 6 laps at submaximal velocity, from which skating economy was calculated (in mL O2 ・ kg–1 ・ km–1). A literature search provided historic data on skating velocity and submaximal V̇O2 (in mL ・ kg–1 ・ min–1), from which skating economy was determined. The association between year and skating economy was determined using linear-regression analysis. Correcting the change in economy for technological innovations resulted in an estimate of the association between year and economy due to athletic improvement. Results: A mean (± SD) skating economy of 73.4 ± 6.4 mL O2 ・ kg–1 ・ km–1 was found in contemporary athletes. Skating economy improved significantly over the historical time frame (–0.57 mL O2 ・ kg–1 ・ km–1 ・ y–1, 95% confidence interval [–0.84, –0.31]). In the final regression model for the klapskate era, with altitude as confounder, skating economy improved with a nonsignificant –0.58 mL O2 ・ kg–1 ・ km–1 ・ y–1 ([–1.19, 0.035]). Conclusions: Skating economy was 73.4 ± 6.4 mL O2 ・ kg–1 ・ km–1 in contemporary athletes and improved over the past ~50 y. The association between year and skating economy due to athletic improvement, for the klapskate era, approached significance, suggesting a possible improvement in economy over these years.

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Josu Gomez-Ezeiza, Jordan Santos-Concejero, Jon Torres-Unda, Brian Hanley, and Nicholas Tam

better running economy. 17 , 18 This implicates the lower limb musculature in ground reaction force attenuation during braking at initial ground contact; this is achieved through optimizing joint stiffness for a more efficient transfer of energy. 19 Whether this neural preparation is also important in

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Filippo Dolci, Andrew E. Kilding, Tania Spiteri, Paola Chivers, Ben Piggott, Andrew Maiorana, and Nicolas H. Hart

specific strength and conditioning programs aimed at preventing reductions in match outputs. One key physiological determinant of running performance is movement economy, 6 which represents the energetic cost (E C ) of movement at submaximal intensities, and is the resultant interaction of an athlete

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Joseph A. McQuillan, Deborah K. Dulson, Paul B. Laursen, and Andrew E. Kilding

Purpose:

To determine the effect of dietary nitrate (NO3 ) supplementation on physiology and performance in well-trained cyclists after 6–8 d of NO3 supplementation.

Methods:

Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg–1 · min–1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3 (NIT) or a NO3 -depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).

Results:

Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (–1.0% ± 3.0%) and exercise economy on d 7 (–1.0% ± 1.6%). However, effects for TT performance time (–0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.

Conclusions:

Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3 supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.

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Carl D. Paton

Purpose:

Aerobic economy is an important factor that affects the performance of competitive cyclists. It has been suggested that placing the foot more anteriorly on the bicycle pedals may improve economy over the traditional foot position by improving pedaling efficiency. The current study examines the effects of changing the anterior-posterior pedal foot position on the physiology and performance of well-trained cyclists.

Methods:

In a crossover study, 10 competitive cyclists completed two maximal incremental and two submaximal tests in either their preferred (control) or a forward (arch) foot position. Maximum oxygen consumption and peak power output were determined from the incremental tests for both foot positions. On two further occasions, cyclists also completed a two-part 60-min submaximal test that required them to maintain a constant power output (equivalent to 60% of their incremental peak power) for 30 min, during which respiratory and blood lactate samples were taken at predetermined intervals. Thereafter, subjects completed a 30-min self-paced maximal effort time trial.

Results:

Relative to the control, the mean changes (±90% confidence limits) in the arch condition were as follows: maximum oxygen consumption, -0.5% (±2.0%); incremental peak power output, -0.8% (±1.3%); steady-state oxygen consumption at 60%, -2.4% (±1.1%); steady-state heart rate 60%, 0.4% (±1.7%); lactate concentration 60%, 8.7% (±14.4%); and mean time trial power, -1.5% (±2.9%).

Conclusions:

We conclude that there was no substantial physiological or performance advantage in this group using an arch-cleat shoe position in comparison with a cyclist’s normal preferred condition.