How rest affects recovery and performance for running, OCR, and endurance sports
Thomas Solomon, PhD.
Updated onReading time approx 4 minutes (800 words).
What you’ll learn:
Rest isn’t a luxury; it’s the bridge between training and adaptation. It’s non-negotiable and you need it to bounce back and get better.
Taking planned rest is likely to speed recovery and help performance. Skipping it is likely to slow you down and hinder your recovery.
Curious about the how and why? Scroll down for the details, the nuances, and the nerdy bits.
The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.
What is rest?
Rest is the space between the work. It’s the minutes between intervals, the hours you sleep between days, the easy days between hard ones, and the lighter weeks inside a training block. That space is where your body resets its internal balance (homeostasis), repairs, and adapts so you can show up ready for the next bout. No mystery, no magic — just physiology taking its time.
Because rest is non-negotiable, smart training balances short-term stress with longer-term load — learn all about that at veohtu.com/trainingload and veohtu.com/trimp. Planning, doing, and reviewing your training keeps that balance in check, don’t forget your headspace. Mental load from decision fatigue, life stress, or endlessly second-guessing your choices can also sap performance — read all about that at veohtu.com/centralfatigue.
What is the scientific evidence on the effect of rest on recovery and athletic performance?
Tapering — reducing training load in the final days before a race — can improve performance. Multiple lines of evidence back this up (see Ramirez-Campillo et al. 2021, Vachon et al. 2020, Grivas et al. 2018, & Bosquet et al. 2007).
Keeping a healthy balance between recent (acute) load and longer-term (chronic) load often means adding more easy time between hard days — and this balance is linked with better performance (see Coyne et al. 2022, Inoue et al. 2022, Lima-Alves et al. 2022, Fox et al. 2018, McLaren et al. 2017, Booth et al. 2017, & Jaspers et al. 2016).
Mental fatigue is a state of feeling tired or flat after long periods of effort or heavy thinking. It can come from anything that burdens your mind, such as training decisions, food choices, recovery planning — the whole circus.
Evidence shows that mentally demanding tasks can hurt cognitive skills and sport-specific skills, raise how hard exercise feels (RPE), and nudge down strength and endurance (see Martin et al. 2019, Habay et al. 2021, Sun et al. 2021, Clemente et al. 2021, & Cao et al. 2022, Alix-Fages et al. 2022, Brown et al. 2019, & McMorris et al. 2018). However, most studies in this field are small and further high-quality randomised controlled trials are needed to be more certain of the effects (Holgado et al. 2023).
Can rest enhance recovery and athletic performance?
Physical rest — temporarily reducing your training load, which before a race is called tapering — is likely to improve performance and speed up the recovery of muscle soreness following exercise. .
Managing the balance between recent (acute) and longer-term (chronic) training load — which often means more rest between hard days — can also improve performance.
On the flipside, mental fatigue likely harms performance. Therefore, resting both your body and your mind is part of smart recovery and the path to optimal performance.
These effect sizesA standardized measure of the magnitude of an effect of an intervention. Unlike p-values, effect sizes show how large the effect is and indicate how meaningful it might be. Common effect size measures include standardised mean difference (SMD), Cohen’s d, Hedges’ g, eta-squared, and correlation coefficients. are small.
And, the effect of rest and training load management appear to be similar between males and females; however, male participants are predominant and females are vastly underrepresented among studies in this field.
Plus, the effect of mental fatigue appears to be similar between trained athletes and untrained folks, but this comparison has not been studied in detail and further work is needed.
Keep in mind: there is a very small number of studies and high heterogeneityHeterogeneity shows how much the results in different studies in a meta-analysis vary from each other. It is measured as the percentage of variation (the I2 value). A rule of thumb: if I2 is roughly 25%, that indicates low heterogeneity (good), 50% is moderate, and 75% indicates high heterogeneity (bad). High heterogeneity means there’s more variability in effects between studies and, therefore, a less precise overall effect estimate. (variability) in study designs and effects between studies. Therefore, there is a high risk of biasRisk of bias in a meta-analysis refers to the potential for systematic errors in the studies included in the analysis. Such errors can lead to misleading/invalid results, and unreliable conclusions. This can arise because of issues with the way participants are selected (randomisation), how data is collected and analysed, and how the results are reported. and the overall certainty of evidenceCertainty of evidence tells us how confident we are that the published results accurately reflect the true effect. It’s based on factors like study design, risk of bias, consistency, directness, precision, and publication bias. Low certainty means more doubt and less confidence, and that future studies could easily change the conclusions. High certainty means that the current evidence is so strong and consistent that future studies are unlikely to change conclusions. is lowA low quality of evidence means that, in general, studies in this field have several limitations. This could be due to inconsistency in effects between studies, a large range of effect sizes between studies, and/or a high risk of bias (caused by inappropriate controls, a small number of studies, small numbers of participants, poor/absent randomization processes, missing data, inappropriate methods/statistics). When the quality of evidence is low, there is more doubt and less confidence in the overall effect of an intervention, and future studies could easily change overall conclusions. The best way to improve the quality of evidence is for scientists to conduct large, well-controlled, high-quality randomized controlled trials.. Therefore, additional high-quality randomised controlled trialsThe “gold standard” approach for determining whether a treatment has a causal effect on an outcome of interest. In such a study, a sample of people representing the population of interest is randomised to receive the treatment or a no-treatment placebo (control), and the outcome of interest is measured before and after the exposure to treatment/control. are needed to increase the certainty (confidence) in the overall effect sizes reported in meta-analysesA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment..
How to use this: Purposefully plan your rest. Keep easy time between hard sessions; protect your sleep before key workouts and races; and in race week, reduce total training load (taper) to arrive fresh. Remove avoidable mental clutter — make simple plans, decide once, and give your brain some peace and quiet in the hours before you want to unleash the beast. None of this needs to be fancy; it just needs to be done.
Information you can trust. All content on Veohtu is meticulously researched and written by Thomas Solomon, PhD. He does not sell supplements, recovery products, or ad space, and he has no sponsorships, brand affiliations, or ambassador roles. Everything you read reflects his independent views, shaped solely by peer-reviewed scientific evidence — and that will never change.
Full list of meta-analyses examining rest for recovery
Here are the meta-analyses I've summarised above:
The counteractive effects of interventions addressing mental fatigue on sport-specific performance among athletes: A systematic review with a meta-analysis. Sun et al. (2024) J Sports Sci.
Assessing the Evidential Value of Mental Fatigue and Exercise Research. Holgado D, Mesquida C, Román-Caballero R. Sports Med. 2023
The Current State of Subjective Training Load Monitoring: Follow-Up and Future Directions. Joseph O. C. Coyne, Aaron J. Coutts, Robert U. Newton & G. Gregory Haff. Sports Med Open. 2022
Internal Training Load Perceived by Athletes and Planned by Coaches: A Systematic Review and Meta-Analysis. Allan Inoue, Priscila dos Santos Bunn, Everton Crivoi do Carmo, Eduardo Lattari & Elirez Bezerra da Silva. Sports Med Open. 2022
The relationship between internal and external loads as a tool to monitor physical fitness status of team sport athletes: a systematic review. Adriano Lima-Alves, João Gustavo Claudino, Daniel Boullosa, Crislaine Rangel Couto, Francisco Teixeira-Coelho, and Eduardo M. Pimenta. Biol Sport. 2022
Mental Fatigue and Basketball Performance: A Systematic Review. Shudian Cao, Soh Kim Geok, Samsilah Roslan, He Sun, Soh Kim Lam and Shaowen Qian. Front Psychol. 2022
Effects of Mental Fatigue on Strength Endurance: A Systematic Review and Meta-Analysis. Carlos Alix-Fages, Jozo Grgic, Pablo Jiménez-Martínez, Eneko Baz-Valle, Carlos Balsalobre-Fernández. Motor Control. 2022
Does mental fatigue affect skilled performance in athletes? A systematic review. He Sun, Kim Geok Soh, Samsilah Roslan, Mohd Rozilee Wazir Norjali Wazir, Kim Lam Soh. PLoS One. 2021
Mental Fatigue and Sport‑Specifc Psychomotor Performance: A Systematic Review. Jelle Habay, Jeroen Van Cutsem, Jo Verschueren, Sander De Bock, Matthias Proost, Jonas De Wachter, Bruno Tassignon, Romain Meeusen, Bart Roelands. Sports Med. 2021
Effects of Mental Fatigue in Total Running Distance and Tactical Behavior During Small-Sided Games: A Systematic Review With a Meta-Analysis in Youth and Young Adult's Soccer Players. Filipe Manuel Clemente, Rodrigo Ramirez-Campillo, Daniel Castillo, Javier Raya-González, Ana Filipa Silva, José Afonso, Hugo Sarmento, Thomas Rosemann, Beat Knechtle. Front. Psychol. 2021
Tapering strategies applied to plyometric jump training: a systematic review with meta-analysis of randomized-controlled trials. Rodrigo Ramirez-Campillo, Lucas A Pereira, David C Andrade, Guillermo Mendez-Rebolledo, Carlos I De La Fuente, Mauricio Castro-Sepulveda, Felipe Garcia-Pinillos, Tomás T Freitas, Irineu Loturco. Journal. 2021
Effects of tapering on neuromuscular and metabolic fitness in team sports: a systematic review and meta-analysis. Adrien Vachon, Nicolas Berryman, Iñigo Mujika, Jean-Baptiste Paquet, Denis Arvisais & Laurent Bosquet. European Journal of Sport Science. 2020
Mental Fatigue Might Be Not So Bad for Exercise Performance After All: A Systematic Review and Bias-Sensitive Meta-Analysis. Darías Holgado, Daniel Sanabria, José C. Perales, and Miguel A. Vadillo. J Cogn. 2020 (NOTE: this article has a correction.)
Physiological Factors Which Influence Cognitive Performance in Military Personnel. Kristy Martin, Julien Périard and David B. Pyne. Journal of the Human Factors and Ergonomics Society. 2019
Effects of Prior Cognitive Exertion on Physical Performance: A Systematic Review and Meta-analysis. Brown DMY, Graham JD, Innes KI, Harris S, Flemington A, Bray SR. Sports Med. 2020
The Association Between Training Load and Performance in Team Sports: A Systematic Review. Jordan L. Fox, Robert Stanton, Charli Sargent, Sally‑Anne Wintour, Aaron T. Scanlan. Sports Med. 2018
The Effects of Tapering on Performance in Elite Endurance Runners: A Systematic Review. Gerasimos V. Grivas. International Journal of Sports Science. 2018
Cognitive fatigue effects on physical performance: A systematic review and meta-analysis. McMorris T, Barwood M, Hale BJ, Dicks M, Corbett J. Physiol Behav. 2018
The Relationships Between Internal and External Measures of Training Load and Intensity in Team Sports: A Meta-Analysis. Shaun J. McLaren, Tom W. Macpherson, Aaron J. Coutts, Christopher Hurst, Iain R. Spears, Matthew Weston. Sports Med. 2017
The effect of training loads on performance measures and injury characteristics in rugby league players. A systematic review. Mark Booth, Rhonda Orr, Stephen Cobley. International Journal of Sports Physiology and Performance. 2017
Relationships Between Training Load Indicators and Training Outcomes in Professional Soccer. Arne Jaspers, Michel S. Brink, Steven G. M. Probst, Wouter G. P. Frencken, Werner F. Helsen. Sports Med. 2016
Effects of Tapering on Performance. A Meta-Analysis. Laurent Bosquet, Jonathan Montpetit, Denis Arvisais, Iñigo Mujika. Med Sci Sports Exerc. 2007
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Who is Thomas Solomon?
My knowledge has been honed following 20+ years of running, cycling, hiking, cross-country skiing, lifting, and climbing, 15+ years of academic research at world-leading universities and hospitals, and 10+ years advising and coaching in athletic performance and lifestyle change.
I have a BSc in Biochemistry, a PhD in Exercise Science, and over 90 peer-reviewed publications in medical journals.
I'm also an ACSM-certified Exercise Physiologist (ACSM-EP), an ACSM-certified Personal Trainer (ACSM-CPT), a VDOT-certified Distance Running Coach, and a UKVRN Registered Nutritionist (RNutr).
Since 2002, I’ve conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, active recovery, biochemistry, and molecular medicine.
And, with my personal experience of competing on the track (800m to 10,000m), the road (5 k to marathon), on the trails, and in the mountains, by foot, bicycle, cross-country ski, and during obstacle course races (OCR), I deeply understand what it's like to train and compete — I've been there, done it, and gotten sweat, mud, and tears on my t-shirt.
Disclaimer: I occasionally mention brands and products, but it is important to know that I don't sell recovery products, supplements, or ad space, and I'm not affiliated with / sponsored by / an ambassador for / receiving advertisement royalties from any brands. I have conducted biomedical research for which I’ve received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, the A.P. Møller Foundation, and the Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on R&D grant applications, and I provide research and scientific writing services for Examine.com. Some of my articles contain links to information provided by Examine.com but I do not receive any royalties or bonuses from those links. Importantly, none of the companies described above have had any control over the research design, data analysis, or publication outcomes of my work. I research and write my content using state-of-the-art, consensus, peer reviewed, and published scientific evidence combined with my empirical evidence observed in practice and feedback from athletes. My advice is, and always will be, based on my own views and opinions shaped by the scientific evidence available. The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.