Artificial night-time lighting has widespread impacts on the natural world, according to a new paper published on 3 November in the journal Nature Ecology & Evolution (1). In particular, night-time lighting disrupts the hormone levels and waking and sleeping patterns of many species. Artificial lighting should therefore be treated as another pollutant and only used where and when it is needed, the authors say.
The requirements of running a 2 hour marathon have been extensively debated but the actual physiological demands of running at ~21.1 km/h have never been reported. We therefore conducted laboratory-based physiological evaluations and measured running economy (O2 cost) while running outdoors at ~21.1 km/h, in world-class distance runners as part of Nike’s ‘Breaking 2’ marathon project. On separate days, 16 male distance runners (age, 29 ± 4 years; height, 1.72 ± 0.04 m; mass, 58.9 ± 3.3 kg) completed an incremental treadmill test for the assessment of V̇O2peak, O2 cost of submaximal running, lactate threshold and lactate turn-point, and a track test during which they ran continuously at 21.1 km/h. The laboratory-determined V̇O2peak was 71.0 ± 5.7 ml/kg/min with lactate threshold and lactate turn-point occurring at 18.9 ± 0.4 and 20.2 ± 0.6 km/h, corresponding to 83 ± 5 % and 92 ± 3 % V̇O2peak, respectively. Seven athletes were able to attain a steady-state V̇O2 when running outdoors at 21.1 km/h. The mean O2 cost for these athletes was 191 ± 19 ml/kg/km such that running at 21.1 km/h required an absolute V̇O2 of ~4.0 L/min and represented 94 ± 3 % V̇O2peak. We report novel data on the O2 cost of running outdoors at 21.1 km/h, which enables better modelling of possible marathon performances by elite athletes. Using the value for O2 cost measured in this study, a sub-2 hour marathon would require a 59 kg runner to sustain a V̇O2 of approximately 4.0 L/min or 67 ml/kg/min.
Objectives: To examine (i) whether levels of, and changes in, athletes’ basic psychological need satisfaction (BPNS) and challenge appraisals predicted in-match thriving; and (ii) if salivary biomarkers could be defined that were related to thriving.
Design: Prospective study design.
Methods: Fifty-one elite male hockey players (Mage=24.94 years, SDage=4.73) completed questionnaires measuring their BPNS and challenge appraisals on seven consecutive days prior to a competitive match, as well as providing saliva samples immediately on waking, and then +0.5, +3, and +5.25h on the day of the match. Saliva was assayed for catabolic (i.e., cortisol) and anabolic (i.e., dehydroepiandrosterone [DHEA]) hormones. In-match thriving was assessed retrospectively using measures of subjective performance and well-being.
Results: Latent growth curve modelling showed pre-match levels of BPNS and challenge appraisals to positively predict thriving. Although not statistically significant, small and moderate negative associations were found for thriving with cortisol concentration (+5.25h sample) and total cortisol exposure across the morning of the match, respectively. DHEA concentration shared a small positive, yet non-significant, association with thriving.
Conclusions: Athletes’ pre-match levels of BPNS and challenge appraisal predict in-match thriving; thus, offering potential mechanisms through which both high-level performance and the experience of well-being can be facilitated. Furthermore, associations suggest that total cortisol exposure across the morning of the match, and cortisol and DHEA levels in pre-match samples may offer sport science and sports medicine practitioners potential biomarkers for thriving. Future research is required to substantiate this initial finding.
Running is a popular way to become or stay physically active and to maintain and improve one’s musculoskeletal load tolerance. Despite the health benefits, running-related injuries affect millions of people every year and have become a substantial public health issue owing to the popularity of running. Running-related injuries occur when the musculoskeletal load exceeds the load tolerance of the human body. Therefore, it is crucial to provide runners with a good estimate of the cumulative loading during their habitual training sessions. In this study, we validated a wearable system to provide an estimate of the external load on the body during running and investigated how much of the cumulative load during a habitual training session is explained by GPS-based spatiotemporal parameters. Ground reaction forces (GRF) as well as 3D accelerations were registered in nine habitual runners while running on an instrumented treadmill at three different speeds (2.22, 3.33, and 4.44 m/s). Linear regression analysis demonstrated that peak vertical acceleration during running explained 80% of the peak vertical GRF. In addition, accelerometer-based as well as GPS-based parameters were registered during 498 habitual running session of 96 runners. Linear regression analysis showed that only 70% of the cumulative load (sum of peak vertical accelerations) was explained by duration, distance, speed, and the number of steps. Using a wearable device offers the ability to provide better estimates of cumulative load during a running program and could potentially serve as a better guide to progress safely through the program. [full text]
The Women's Game (Australia), Janakan Seemampillai from
Heading Pro, a specially designed football that is meant to keep players safe when heading the ball, is the brainchild of former Socceroo and current Western Sydney W-League coach Dean Heffernan and close friend Andrew Head, a specialist in the product development of footballs.
Researchers at Dartmouth College, Wuhan University, Southeast University, and Microsoft Research have developed a fabric that can identify what foods and other types of objects placed on it (hat tip to Engadget).
Dubbed Capacitivo, the technology attaches a grid of electrodes to a textile. By applying an electric field to the fabric and some machine learning, objects placed on it can be identified by measuring any shift in capacitance.
The technology can detect different types of food, even when those items are inside containers like water glasses and bowls. According to the paper, the tech also has an average accuracy of 90.71 percent.
Growing clusters of coronavirus infections in youth sports, coupled with pandemic fatigue, are complicating the battle to control new cases across Massachusetts, health department directors say.
They say the hurdles, coming as the number of cases soar across the state, are making their job of tracking down close contacts of infected residents exponentially more complex than earlier in the pandemic. That’s reflected in recent state data indicating that the source of infections in about half of new COVID-19 cases is a mystery — a troubling trend because without knowing how and where people are getting infected, it’s difficult to prevent further infections.
Etiologic factors associated to running injuries are reviewed, with an emphasis on the transient shock waves experienced during foot strike. In these terms, impact mechanics are analyzed from both, a biomechanical and medical standpoint and evaluated with respect injury etiology, precursors and morbidity. The complex interaction of runner specific characteristics on the employed footwear system are examined, providing insight into footwear selection that could act as a preventive measure against non-acute trauma incidence. In conclusion, and despite the vast literature on running-related injury-risks, only few records could be identified to consider the effect of shoe cushioning and anthropometric data on injury prevalence. Based on this literature, we would stress the importance of such considerations in future studies aspiring to provide insight into running related injury etiology and prevention. [full text]
FIFPRO notes the accumulated workload for players in the first quarter of European football’s 2020-2021 season and the mental and physical burden they are facing until 2022. The current handling of the match calendar during this emergency period lacks sufficient considerations for their health, well-being and performance and requires an urgent and ongoing revision by competition organisers.
… We want five substitutions,” Guardiola said on NBCSN after the match. “An international player, Alexander-Arnold is injured. All around the world, five substitutions but here we think we’re special. I will demand if the people allow my voice to have five substitutions. If not, it’s difficult to sustain it.”
Earlier this weekend, Manchester United boss Ole Gunnar Solskjaer complained about kickoff times after his side beat Everton at the weekend, and Klopp backed his rival.
“If you want to have good football then give the boys a few hours more,” Klopp said via the BBC. “We had after the triple header in the international break we played 12:30 (7:30 am ET). The boys played Wednesday night in Peru, that is not possible. Somebody has to start thinking.”
Here’s a quick and convenient way of finding out whether you’re ready to run a two-hour marathon. Head to the track and run six laps (roughly 1.5 miles) at two-hour pace (4:34.6 per mile), then run one more lap as fast as you can. Have a nearby exercise physiologist fit you with a portable oxygen-measuring mask, to measure your energy consumption at that pace. Then crunch the data to see whether your metabolism is settling into a sustainable pattern, or whether it’s spiraling out of control toward a fiery explosion.
That’s one of several tests that at least 16 elite runners underwent during the selection process for Nike’s 2017 Breaking2 race, which Eliud Kipchoge ended up winning in 2:00:25. Now the scientists responsible, including teams from Andrew Jones’s group at the University of Exeter in Britain and the Nike Sport Research Lab in Beaverton, have published some of the data in the Journal of Applied Physiology.
To save its season, the league took on giant costs and a massive logistical challenge. It also partnered with its players on social justice advocacy. The result was a case study in leadership.