Six days of dietary nitrate supplementation in the form of beetroot juice (~0.5 L/d) has been reported to reduce pulmonary oxygen uptake (VO2) during submaximal exercise and increase tolerance of high-intensity work rates, suggesting that nitrate can be a potent ergogenic aid. Limited data are available regarding the effect of nitrate ingestion on athletic performance, and no study has investigated the potential ergogenic effects of a small-volume, concentrated dose of beetroot juice. The authors tested the hypothesis that 6 d of nitrate ingestion would improve time-trial performance in trained cyclists. Using a double-blind, repeated-measures crossover design, 12 male cyclists (31 ± 3 yr, VO2peak = 58 ± 2 ml · kg−1 · min−1, maximal power [Wmax] = 342 ± 10 W) ingested 140 ml/d of concentrated beetroot (~8 mmol/d nitrate) juice (BEET) or a placebo (nitrate-depleted beetroot juice; PLAC) for 6 d, separated by a 14-d washout. After supplementation on Day 6, subjects performed 60 min of submaximal cycling (2 × 30 min at 45% and 65% Wmax, respectively), followed by a 10-km time trial. Time-trial performance (953 ± 18 vs. 965 ± 18 s, p < .005) and power output (294 ± 12 vs. 288 ± 12 W, p < .05) improved after BEET compared with PLAC supplementation. Submaximal VO2 was lower after BEET (45% Wmax = 1.92 ± 0.06 vs. 2.02 ± 0.09 L/min, 65% Wmax 2.94 ± 0.12 vs. 3.11 ± 0.12 L/min) than with PLAC (main effect, p < .05). Wholebody fuel selection and plasma lactate, glucose, and insulin concentrations did not differ between treatments. Six days of nitrate supplementation reduced VO2 during submaximal exercise and improved time-trial performance in trained cyclists.
Naomi M. Cermak, Martin J. Gibala and Luc J.C. van Loon
Christian Lorenzen, Morgan D. Williams, Paul S. Turk, Daniel L. Meehan and Daniel J. Cicioni Kolsky
Running velocity reached at maximal oxygen uptake (vVO2max) can be a useful measure to prescribe training intensity for aerobic conditioning. Obtaining it in the laboratory is often not practical, and average velocities from time trials are an attractive alternative. To date, the efficacies of such practices for team sport players are unknown. This study aimed to assess the relationship between vVO2max obtained in the laboratory against two time-trial estimates (1500 m and 3200 m).
During the early preseason, elite Australian Rules football players (n = 23, 22.7 ± 3.4 y, 187.7 ± 8.2 cm, 75.5 ± 9.2 kg) participated in a laboratory test on a motorized treadmill and two outdoor time trials.
Based on average velocity the 1500-m time-trial performance (5.01 ± 0.23 m·s−1) overestimated (0.36 m·s−1, d = 1.75), whereas the 3200-m time trial (4.47 ± 0.23 m·s−1) underestimated (0.17 m·s−1, d = 0.83) the laboratory vVO2max (4.64 ± 0.18 m·s−1). Despite these differences, both 1500-m and 3200-m time-trial performances correlated with the laboratory measure (r = -0.791; r = -0.793 respectively). Both subsequent linear regressions were of good ft and predicted the laboratory measure within ± 0.12 m·s−1.
Estimates of vVO2max should not be used interchangeably, nor should they replace the laboratory measure. When laboratory testing is not accessible for team sports players, prescription of training intensity may be more accurately estimated from linear regression based on either 1500-m or 3200-m time-trial performance than from the corresponding average velocity.
Bent R. Rønnestad, Tue Rømer and Joar Hansen
Performance in cross-country (XC) skiing is highly related to maximal oxygen consumption (VO 2 max). 1 , 2 The high VO 2 max values in XC skiers could be related to numerous factors such as genetics, training volume, training periodization, and amount of high-intensity aerobic interval training
Francisco J. Amaro-Gahete, Lucas Jurado-Fasoli, Alejandro R. Triviño, Guillermo Sanchez-Delgado, Alejandro De-la-O, Jørn W. Helge and Jonatan R. Ruiz
protocol is considered an important factor in endurance exercise performance as well and in cardiovascular health. 5 Moreover, another important variable is the exercise intensity at which MFO occurs, so called Fat max . Both MFO and Fat max , together with maximum oxygen uptake (VO 2 max), VO 2 max
Richard Latzel, Olaf Hoos, Sebastian Stier, Sebastian Kaufmann, Volker Fresz, Dominik Reim and Ralph Beneke
anaerobic energy systems is unknown. Previously, assumptions on energy demand in basketball were drawn from observation of in-game activities, 6 time–motion analyses of basketball matches, 1 , 7 – 9 and indirect estimation of oxygen uptake (VO 2 ) by heart rate (HR) measurements 10 or direct measurement
Volker Scheer, Tanja I. Janssen, Solveig Vieluf and Hans-Christian Heitkamp
and exercise testing strategies to predict performance and improve training concepts and competition results. Values that are classically used to predict running performance include maximal oxygen uptake (VO 2 max), percentage of VO 2 max, ventilatory and lactate thresholds, and running economy. 1
Emma M. Crum, Matthew J. Barnes and Stephen R. Stannard
). Increases in plasma NO have been associated with improvements in the efficiency of oxygen (O 2 ) use during exercise; specifically, acute BRJ intake has led to a 3–5% reduction in the O 2 uptake (VO 2 ) required to perform at a given level of submaximal cycling, and a 15–25% improvement in performance
Øyvind Skattebo, Thomas Losnegard and Hans Kristian Stadheim
Because of the wide range of physiological, biomechanical, and anthropometrical demands in endurance sports, specialization is often considered a prerequisite for reaching an elite performance level. As an example, marathon runners display lower maximal oxygen uptake (VO 2 max) than 5- to 10-km
Ana C. Holt, Daniel J. Plews, Katherine T. Oberlin-Brown, Fabrice Merien and Andrew E. Kilding
to occur within 24 hours following exercise performed at <70% maximal oxygen uptake (VO 2 max), 24 to 48 hours following exercise performed at 70% to 82% VO 2 max, and >48 hours following exercise performed at >82% VO 2 max. 2 Although research investigating athletic populations demonstrates
Richard J. Taylor, Dajo Sanders, Tony Myers, Grant Abt, Celia A. Taylor and Ibrahim Akubat
forwards and 5 backs) competing as the current champions of the Association of Colleges Midland Elite League agreed to participate in the study (mean [SD] age 18.4 [1.0] y, height 181.3 [5.9] cm, body mass 85.9 [13.0] kg, maximal oxygen uptake [VO 2 max] 56 [6.7] mL · kg −1 · min −1 ). The academy team is