RESEARCH: Studies from 11 to 17 Nov 24
Sharing research and insights from coaches, scientists and athletes to help us improve endurance performance.
This week’s quick summary:
Prediction of half-marathon performance
Declining marathon performances under a warming climate
Associations of “weekend warrior” physical activity with health
The impact of daytime napping on athletic performance
Persistence of mental fatigue on motor control
PHYSIOLOGY: Prediction of half-marathon performance
Studies that set out to predict performance are often identifying correlation rather than the causes of these performances. However, understanding which variables appear to correlate to better performances can provide ideas of what to test and try in training. In this study, the authors set out "to develop an easily accessible and applicable model to predict half-marathon performance in male recreational half-marathon runners".
STUDY DETAILS
The study included 202 male recreational half-marathon runners from Zhejiang Province, China, with a median age of 49 years.
Participants completed questionnaires assessing various epidemiological factors related to running performance.
The sample was divided into a training set (141 runners) and a testing set (61 runners) to develop and validate the nomogram.
Three key predictors of better half-marathon performance (finishing time ≤ 105 minutes) were identified: longer monthly running distance, faster mean training pace, and better sleep quality.
The nomogram demonstrated good predictive ability, with area under the curve (AUC) values of 0.750 and 0.743 for the training and testing sets, respectively.
PRACTICAL TAKEAWAY
These results showed that total training volume, training pace, and sleep were associated with better performances. These three factors are probably not a surprise to any coaches or athletes, but it is interesting to see sleep included as this usually doesn’t appear in studies looking at performance. My recommendation for athletes is to do as much training volume as they can given their life circumstances and to make sure they’re sleeping enough to support this training.
RELATED RESEARCH
HEAT: Wasted efforts of elite Marathon runners under a warming climate primarily due to atmospheric oxygen reduction
Comparing the performances of athletes in different temperatures at different races can present uncertainty. In particular, there may be variation due to comparing two different athletes rather than looking at how one athlete performs in two different temperatures. In this study, the authors explained that "via following each athlete to eliminate these uncertainties, we show that elite athletes' marathon-running performance tends to monotonically worsen as ambient temperature rises except when it is extremely cold”.
STUDY DETAILS
The study analysed the best 16 athletes from each of the six continents for both men and women.
Performance worsened by 0.56 minutes per °C (0.39 for men, 0.71 for women) when temperatures exceeded 15°C.
Theoretical analysis using global marathon performance and weather data revealed that over half of this effect is due to reduced oxygen partial density in warmer air.
World-top athletes' marathon performance worsened linearly as ambient pressure decreased and slightly worsened with rising relative humidity, unless extremely wet.
Projections suggest climate change could slow Olympic marathon times by 2.51 minutes under a high emission scenario and 1.06 minutes under an intermediate scenario by 2100, compared to 2020.
PRACTICAL TAKEAWAY
These results show that for marathon runners a race in temperatures greater than 15°C will be slower. The optimal range of race temperatures for the marathon appear to be 8-15°C. My recommendation for athletes looking to race their fastest marathon is to choose a flat and fast course where the temperature is below 15°C. Fortunately most spring and autumn marathons meet these temperature requirements.
RELATED RESEARCH
TRAINING: Associations of “weekend warrior” physical activity with incident disease and cardiometabolic health
Many athletes have limited time to train and often the first sessions that are lost are during the week when time constraints are greatest. These athletes are sometimes called “weekend warriors” as they do most of their training and racing during the weekend. In this study, the authors aimed “to investigate the effects of "weekend warrior" versus regular physical activity patterns on various health outcomes, particularly cardiometabolic conditions”.
STUDY DETAILS
The study included 89,573 participants from the UK Biobank, with a mean age of 62 years and 56% women.
Participants wore wrist-based accelerometers for one week to measure physical activity patterns.
The researchers compared inactive individuals (<150 minutes of moderate-to-vigorous activity/week) to those following weekend warrior or regular activity patterns.
Both weekend warrior and regular activity patterns were associated with lower risk of over 200 incident diseases compared to inactivity.
The strongest associations were observed for cardiometabolic conditions, including hypertension, diabetes, obesity, and sleep apnoea, with similar risk reductions for both activity patterns.
PRACTICAL TAKEAWAY
This study showed that achieving the recommended 150 minutes of moderate-to-vigorous physical activity per week is beneficial for overall health, regardless of whether it's spread throughout the week or concentrated on weekends. Both patterns show similar protective effects against cardiometabolic conditions. I would not recommend aiming to be a weekend warrior on the basis of these results, but I would suggest that if you can’t train regularly during the week, then doing what you can on the weekend is a great alternative.
RELATED RESEARCH
How to equalize high- and low-intensity endurance exercise dose
Best Time of Day for strength and endurance training to improve health and performance
SLEEP: The impact of daytime napping on athletic performance
Research has shown that mid-day napping can be an effective strategy to combat sleep debt and aid recovery in athletes, regardless of their nocturnal sleep duration. In this review, the authors aimed “to summarise the available evidence on how napping influences exercise and cognitive performance, as well as athletes' perceptual responses”.
REVIEW DETAILS
Studies have shown mixed results regarding the influence of napping on athletic performance.
Mid-day naps can enhance or restore various aspects of exercise and cognitive performance, as well as improve athletes' perceptual responses, both after a normal night's sleep and after sleep loss.
Long-term naps (>35-90 minutes) generally provide superior benefits compared to short-term naps (20-30 minutes).
The mechanisms behind performance enhancement following napping are not yet fully understood.
Sleep inertia may be responsible for the absence of benefits or even performance deterioration observed in some studies.
PRACTICAL TAKEAWAY
The results of this review suggest that athletes should consider incorporating mid-day naps into their routines, with longer naps (35-90 minutes) potentially offering greater benefits. My recommendation for athletes is to include naps in their day if they can (see the first study in this week’s newsletter correlating sleep with half-marathon performance). If that’s not possible during the week, maybe aiming for naps on the weekend to become a “weekend warrior napper” might also help!
RELATED RESEARCH
FATIGUE: Persistence of mental fatigue on motor control
Mental fatigue can have a detrimental impact on performance and often arises due to life stresses or during longer races. In this study, the authors explain that "while the effects of mental fatigue on motor performance have been clearly demonstrated, questions about the persistence of these effects and the time course of recovery from mental fatigue have been poorly investigated." The study sought to fill this knowledge gap by examining how mental fatigue affects arm-pointing tasks and brain activity over time.
STUDY DETAILS
15 participants performed an arm-pointing task before and after a 32-minute cognitively demanding Time Load Dual Back (TLDB) task.
Arm-pointing tasks were repeated immediately, 10 minutes, and 20 minutes after the TLDB task.
Electroencephalography (EEG) was continuously recorded throughout the experiment.
Subjective mental fatigue increased significantly after the TLDB task and decreased during the 20-minute recovery period, but did not return to baseline levels.
EEG showed increased theta and alpha power over time, while arm-pointing movement duration gradually increased during recovery, indicating persistent mental fatigue effects.
PRACTICAL TAKEAWAY
The results of this study showed that even though participants thought they had recovered from the mentally fatiguing task, their performance did not return to baseline even after 20 minutes of recovery. This highlights the importance of allowing time to recover fully even if an athlete feels they are recovered. My recommendation for athletes would be to provide a buffer of 20 to 30 minutes before key training sessions to ensure that they don’t carry any fatigue from the pre-training life into those sessions.
RELATED RESEARCH
Quick summary from last week’s paid newsletter
Paid subscribers receive a newsletter every week and have full access to all newsletters listed in the archives (505 studies and practical takeaways). Last week, the newsletter covered studies on the following topics:
Pacing and heat stress differentially affect elite marathon performance
Achilles tendon thickness reduces immediately after a marathon
Vegan and omnivore diets impact on post-downhill running economy
Effects of exercise training on mitochondrial and capillary growth
Nutritional strategies in an elite wheelchair marathoner at 3900 m altitude
