In this study, criteria are used to identify whether a subject has elicited maximal oxygen uptake. We evaluated the validity of traditional maximal oxygen uptake criteria and propose a novel set of criteria. Twenty athletes completed a maximal oxygen uptake test, consisting of an incremental phase and a subsequent supramaximal phase to exhaustion (verification phase). Traditional and novel maximal oxygen uptake criteria were evaluated. Novel criteria were: oxygen uptake plateau defined as the difference between modelled and actual maximal oxygen uptake >50% of the regression slope of the individual oxygen uptake–workrate relationship; as in the first criterion, but for maximal verification oxygen uptake; and a difference of ≤4 beats·min^–1 between maximal heart rate values in the 2 phases. Satisfying the traditional oxygen uptake plateau criterion was largely an artefact of the between-subject variation in the oxygen uptake–workrate relationship. Secondary criteria, supposedly an indicator of maximal effort, were often satisfied long before volitional exhaustion, even at intensities as low as 61% maximal oxygen uptake. No significant mean differences were observed between the incremental and verification phases for oxygen uptake (t = 0.4; p = 0.7) or heart rate (t = 0.8; p = 0.5). The novel oxygen uptake plateau criterion, maximal oxygen uptake verification criterion, and maximal heart rate verification criterion were satisfied by 17, 18, and 18 subjects, respectively. The small individual absolute differences in oxygen uptake between incremental and verification phases observed in most subjects provided additional confidence that maximal oxygen uptake was elicited. Current maximal oxygen uptake criteria were not valid and novel criteria should be further explored.

Athletes use many different strategies to enhance their performance, including clothing and footwear, training regimes, diets, and ergogenic aids. The use of ergogenic aids is believed to be widespread, with a variety of legal as well as illegal substances being used previously and currently. Among the more popular ergogenic aids is the use of sodium bicarbonate or sodium citrate, collectively recognized as "buffers." These substances potentially provide the body with added resistance against fatigue caused by deleterious changes in acid-base balance brought about by a variety of exercise modes and durations. The popularity of buffering has generated a plethora of research dating back to the 1930s, which continues to date. The issues surrounding buffering revolve around the dosage size, timing of ingestion, and the type of exercise to benefit from the use of buffers. We hope this review addresses these pertinent issues.

Sodium bicarbonate (NaHCO3) is a buffering agent that is suggested to improve performance by promoting the efflux of hydrogen ions from working cells and tissues. Research surrounding its efficacy as an ergogenic aid is conflicting, making it difficult to draw conclusions as to its effectiveness for training and competition. This study performed a meta-analysis of relevant research articles to allow the development of concise practical recommendations for coaches and athletes. The overall effect size for the influence of NaHCO3 on performance was moderate, and was significantly lower for specifically trained as opposed to recreationally trained participants.

Context: Epidemiologic findings of higher incidences of hamstrings muscle strains during the latter stages of soccer match play have been attributed to fatigue. Objective: To investigate the influence of soccer-specific fatigue on the peak eccentric torque of the knee flexor muscles. Design: Descriptive laboratory study. Setting: Controlled laboratory environment. Patients or Other Participants: Ten male professional soccer players (age = 24.7 ± 4.4 years, mass = 77.1 ± 8.3 kg, V˙o_2max = 63.0 ± 4.8 mL·kg⁻¹·min⁻¹). Intervention(s): Participants completed an intermittent treadmill protocol replicating the activity profile of soccer match play, with a passive halftime interval. Before exercise and at 15-minute intervals, each player completed isokinetic dynamometer trials. Main Outcome Measure(s): Peak eccentric knee flexor torque was quantified at isokinetic speeds of 180° · s⁻¹, 300° · s⁻¹, and 60° · s⁻¹, with 5 repetitions at each speed. Results: Peak eccentric knee flexor torque at the end of the game (T_300eccH105 = 127 ± 25 Nm) and at the end of the passive halftime interval (T_300eccH60 = 133 ± 32 Nm) was reduced relative to T_300eccH00 (167 ± 35 Nm, P < .01) and T_300eccH15 (161 ± 35 Nm, P = .02). Conclusions: Eccentric hamstrings strength decreased as a function of time and after the halftime interval. This finding indicates a greater risk of injuries at these specific times, especially for explosive movements, in accordance with epidemiologic observations. Incorporating eccentric knee flexor exercises into resistance training sessions that follow soccer-specific conditioning is warranted to try to reduce the incidence or recurrence of hamstrings strains.