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Open access

Microdosing: Old Wine in a New Bottle? Current State of Affairs and Future Avenues

José Afonso, Fábio Yuzo Nakamura, Ivan Baptista, Gonçalo Rendeiro-Pinho, João Brito, and Pedro Figueiredo

Purpose: Microdosing of exercise aims to deliver smaller daily training doses but at a higher weekly frequency, adding up to a similar weekly volume as in nonmicrodosed training. This commentary critically discusses this concept, which appears to be a rebranding of the “old” distributed practice of motor learning. Development: We propose that microdosing should relate to the minimal dose that develops or at least maintains the selected capacities or skills as this training dose matters to practitioners, especially during the in-season period. Moreover, microdosing has been applied mainly to develop strength and endurance, but abilities such as sprinting and changing direction could also be microdosed, as well as technical–tactical skills. Conclusions: The concept of microdosing should be reframed to avoid redundancy with the concept of distributed practice while providing valuable information concerning the minimum doses that still generate the intended effects and the thresholds that determine whether a dose is “micro” or not.

Open access

Continuous Thermoregulatory Responses to a Mass-Participation 89-km Ultramarathon Road Race

Christopher Byrne, Aurelien Cosnefroy, Roger Eston, Jason K.W. Lee, and Tim Noakes

Purpose: To continuously measure body core temperature (T c) throughout a mass-participation ultramarathon in subelite recreational runners to quantify T c magnitude and the influence of aerobic fitness and body fat. Methods: Twenty-three participants (19 men and 4 women; age 45 [9] y; body mass 72.0 [9.3] kg; body fat 26% [6%]; peak oxygen uptake 50 [6] mL·kg−1·min−1) had gastrointestinal temperature measured during an 89-km ultramarathon. Prerace-to-postrace changes in body mass, plasma sodium, and fluid and food recall quantified body water balance. Results: In maximal environmental conditions of 26.3 °C and 53% humidity, 21 of the 23 participants finished in 10:28 (01:10) h:min while replacing 49% (27%) of sweat losses, maintaining plasma sodium (140 [3] mmol·L−1), and dehydrating by 4.1% (1.3%). Mean maximum T c was 39.0 (0.5) (range 38.2–40.1 °C) with 90% of race duration ≤39.0 °C. Mean maximum ΔT c was 1.9 (0.9) (0.9–2.7 °C) with 95% of race duration ≤2.0 °C. Over 0 to 45 km, associations between ΔT c and peak oxygen uptake (positive) and body fat (negative) were observed. Over 58 to 89 km, associations between T c and peak oxygen uptake (negative) and body fat (positive) were observed. Conclusions: Modest T c responses were observed in recreational ultramarathon runners. Runners with higher levels of aerobic fitness and lower levels of body fat demonstrated the greatest changes in T c during the first half of the race. Conversely, runners with lower levels of aerobic fitness and higher levels of body fat demonstrated the greatest absolute T c in the final third of the race.

Open access

Football in Times of COVID-19: A Recapitulation of Preventive Measures and Infection Control Policies Aiming at a Safe Game Environment

Karim Chamari, Ismail Dergaa, Inigo Mujika, Yorck Olaf Schumacher, Montassar Tabben, and Helmi Ben Saad

Coronavirus disease 2019 (COVID-19) resulted in sporting event suspensions and cancellations, affecting competition calendars worldwide during 2020 and 2021. This challenged high-performance athletes’ capacity to complete physical, technical, or tactical training during restricted movement measures (lockdown). With the Football World Cup organized in the last quarter of 2022, the past period of training and match disturbances challenged footballers concerning their performance and potential higher risk of injury at official matches’ resumption. There has been considerable debate about the management of resuming professional football (soccer) during the COVID-19 pandemic. Governing bodies worldwide implemented measures to ensure a safe resumption of football. These precautionary measures aimed to protect the health of players, their support staff, and officials around the pitch and ensure the enjoyment of the event by spectators in the football stadiums. We have therefore narratively reviewed scientific papers about how football has resumed on the pitch and in the stands with special focus on the COVID-19 infection control strategies allowing footballers to perform again and supporters to enjoy the game after the 2020 global stop to sport.

Open access

Physiology and Performance Prospects of a Women’s Sub-4-Minute Mile

Samuel N. Cheuvront

When will women run a sub-4-minute mile? The answer seems to be a distant future given how women’s progress has plateaued in the mile, or its better studied metric placeholder, the 1500 m. When commonly accepted energetics principles of running, along with useful field validation equations of the same, are applied to probe the physiology underpinning the 10 all-time best women’s mile performances, insights gained may help explain the present 12.34-second shortfall. Insights also afford estimates of how realistic improvements in the metabolic cost of running could shrink the difference and bring the women’s world record closer to the fabled 4-minute mark. As with men in the early 1950s, this might stir greater interest, excitement, participation, and depth in the women’s mile, the present absence of which likely contributes to more pessimistic mathematical modeling forecasts. The purpose of this invited commentary is to provide a succinct, theoretical, but intuitive explanation for how women might get closer to their own watershed moment in the mile.

Open access

Analysis of Recovery Methods’ Efficacy Applied up to 72 Hours Postmatch in Professional Football: A Systematic Review With Graded Recommendations

Sérgio M. Querido, Régis Radaelli, João Brito, João R. Vaz, and Sandro R. Freitas

Background: Sleep, nutrition, active recovery, cold-water immersion, and massage were recently reported as the most used postmatch recovery methods in professional football. However, the recommendations concerning the effect of these methods remain unclear. Purpose: To systematically review the literature regarding the effectiveness of the most common recovery methods applied to male and female football players (or other team sports) 72 hours postmatches and to provide graded recommendations for their use. Methods: A systematic search of the literature was performed, and the level of evidence of randomized and nonrandomized studies was classified as 1 or 2, respectively, with additional ++, +, and − classification according to the quality of the study and risk of bias. Graded recommendations were provided regarding the effectiveness of recovery methods for physical, physiological, and perceptive variables. Results: From the 3472 articles identified, 39 met the inclusion criteria for analysis. The studies’ levels of evidence varied among methods (sleep: 2+ to 1++; nutrition: 2− to 1+; cold-water immersion: 2− to 1++; active recovery: 2− to 1+; and massage: 1− to 1+). Different graded recommendations were attributed, and none of them favored the effective use of recovery methods for physiological and physical parameters, whereas massage and cold-water immersion were recommended as beneficial for perceptive variables. Conclusions: Cold-water immersion and massage can be recommended to recover up to 72 hours postmatch at a perceptive level. However, there is a current need for high-quality research that identifies effective recovery strategies that enhance recovery at the physical and physiological levels.

Open access

Football Research Takes Center Stage

Iñigo Mujika and Karim Chamari

Open access

Training Load: Differentiating Training Volume and Training Dose

Louis Passfield, Juan M. Murias, Massimo Sacchetti, and Andrea Nicolò

Open access

Comment on Passfield et al: Defending the Use of Oxygen Uptake as a Criterion Measure for Training Load

Katie M. Slattery, Lee K. Wallace, and Aaron J. Coutts

Open access

Comment on Passfield et al: Validity of the Training-Load Concept

Shaun J. McLaren, Tzlil Shushan, Christoph Schneider, and Patrick Ward

Open access

Erratum: Fast-Speed Compared With Slow-Speed Eccentric Muscle Actions Are Detrimental to Jump Performance in Elite Soccer Players In-Season