The Restorative Role of Daytime Naps in Mentally Fatigued Endurance Athletes

NCT07580131 | Completed

• 1 other identifier: Nap&Run01
• Study Type: interventional
• Target: 11
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized, counterbalanced crossover study investigated whether a 30-minute daytime nap can mitigate the effects of experimentally induced mental fatigue in amateur master endurance athletes. Male athletes completed two home-based experimental sessions separated by one week: a mental fatigue condition, in which a 30-minute cognitively demanding task battery preceded the nap, and a control condition, in which participants took only the nap. Sleep parameters during the nap were monitored by wrist actigraphy, and perceived sleep quality was assessed after awakening. Subjective sleepiness, perceived mental fatigue, and cognitive performance were evaluated before the nap, immediately after the nap, and/or 30 minutes after the nap. The study examined whether mental fatigue influenced nap characteristics and whether the nap improved recovery-related outcomes. The main outcomes included actigraphy-derived nap parameters, perceived sleep quality, sleepiness assessed with the Karolinska Sleepiness Scale, perceived mental fatigue assessed using a visual analogue scale, and cognitive performance assessed with a Flanker task.

Conditions

Mental Fatigue; Sleep; Endurance Exercise; Daytime Napping

Keywords

Sleep; Actigraphy; Napping; Recovery; Running

Outcome Measures

Primary Outcomes (1)

• Perceived mental fatigue

  Perceived mental fatigue was assessed using a 100-mm visual analogue scale for mental fatigue (VAS-MF), anchored from 0-mm "No mental fatigue" to 100-mm "Maximum mental fatigue." Participants marked the point that best represented their perceived level of mental fatigue.

  Before the nap, immediately after the nap, and 30 minutes after the nap in each experimental condition.

Secondary Outcomes (9)

• Subjective sleepiness

  Before the nap, immediately after the nap, and 30 minutes after the nap

• Flanker Task Reaction Time

  30 minutes after the nap in each experimental condition.

• Perceived Nap Sleep Quality

  Immediately after the nap in each experimental condition.

• Actigraphy-Derived nap start time

  During the 30-minute daytime nap in each experimental condition.

• Actigraphy-Derived nap time in bed

  During the 30-minute daytime nap in each experimental condition.

Study Arms (2)

Mental Fatigue + Daytime Nap

EXPERIMENTAL

Participants completed a 30-minute mental fatigue induction protocol consisting of cognitively demanding tasks, followed by a 30-minute daytime nap performed at home between 14:00 and 15:00. Subjective sleepiness, perceived mental fatigue, nap characteristics, perceived sleep quality, and cognitive performance were assessed before and/or after the nap.

Behavioral: Mental Fatigue Induction Protocol; Behavioral: Daytime Nap

Daytime Nap Control

ACTIVE COMPARATOR

Participants completed the control condition consisting of a 30-minute daytime nap performed at home between 14:00 and 15:00, without the preceding mental fatigue induction protocol. Subjective sleepiness, perceived mental fatigue, nap characteristics, perceived sleep quality, and cognitive performance were assessed before and/or after the nap.

Behavioral: Daytime Nap

Interventions

Mental Fatigue Induction Protocol BEHAVIORAL

Participants completed a 30-minute computerized cognitive task battery designed to induce mental fatigue before the daytime nap. The protocol consisted of three consecutive 10-minute cognitively demanding tasks: a Flanker task, a memory task, and a Stroop task.

Mental Fatigue + Daytime Nap

Daytime Nap BEHAVIORAL

Participants took a 30-minute daytime nap at home between 14:00 and 15:00, at least one hour after lunch, in a quiet and dimly lit room. Nap characteristics were monitored using wrist actigraphy, and perceived sleep quality was assessed after awakening.

Daytime Nap Control; Mental Fatigue + Daytime Nap

Eligibility Criteria

• Age: 28 Years - 50 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Male amateur master endurance athletes
• Age between 28 and 50 years
• Peak oxygen uptake (VO₂peak) ≥55 mL·kg-¹·min-¹
• Habitual nocturnal sleep duration of at least 7 hours
• Able and willing to complete both experimental sessions and daytime nap procedures

You may not qualify if:

• Diagnosed medical condition or injury
• Diagnosed sleep disorder
• Use of medications or supplements affecting sleep or cognition, including melatonin
• Habitual sleep duration of less than 7 hours per night
• Inability to nap during the experimental sessions

Sponsors & Collaborators

• L.U.de.S. Sagl: lead
• Universty of Milan: collaborator
• University of Physical Culture in Cracow: collaborator
• University of Rennes: collaborator
• Universita Telematica E-Campus: collaborator

Study Sites (1)

University of Milan

Milan, Italy

Location

Related Publications (6)

• Kaida K, Takahashi M, Akerstedt T, Nakata A, Otsuka Y, Haratani T, Fukasawa K. Validation of the Karolinska sleepiness scale against performance and EEG variables. Clin Neurophysiol. 2006 Jul;117(7):1574-81. doi: 10.1016/j.clinph.2006.03.011. Epub 2006 May 6.

  PMID: 16679057 BACKGROUND

• Marcora SM, Staiano W, Manning V. Mental fatigue impairs physical performance in humans. J Appl Physiol (1985). 2009 Mar;106(3):857-64. doi: 10.1152/japplphysiol.91324.2008. Epub 2009 Jan 8.

  PMID: 19131473 BACKGROUND

• Macari M, Pela IR, Silva CA, Viana RS. Fever response induced by intravenous and intracerebroventricular injection of pyrogen in thyroidectomised and protein-calorie malnourished rabbits. Pflugers Arch. 1990 Jan;415(4):440-3. doi: 10.1007/BF00373621.

  PMID: 2107523 BACKGROUND

• Mesas AE, Nunez de Arenas-Arroyo S, Martinez-Vizcaino V, Garrido-Miguel M, Fernandez-Rodriguez R, Bizzozero-Peroni B, Torres-Costoso AI. Is daytime napping an effective strategy to improve sport-related cognitive and physical performance and reduce fatigue? A systematic review and meta-analysis of randomised controlled trials. Br J Sports Med. 2023 Apr;57(7):417-426. doi: 10.1136/bjsports-2022-106355. Epub 2023 Jan 23.

  PMID: 36690376 BACKGROUND

• Lastella M, Halson SL, Vitale JA, Memon AR, Vincent GE. To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance. Nat Sci Sleep. 2021 Jun 24;13:841-862. doi: 10.2147/NSS.S315556. eCollection 2021.

  PMID: 34194254 BACKGROUND

• Van Cutsem J, Marcora S, De Pauw K, Bailey S, Meeusen R, Roelands B. The Effects of Mental Fatigue on Physical Performance: A Systematic Review. Sports Med. 2017 Aug;47(8):1569-1588. doi: 10.1007/s40279-016-0672-0.

  PMID: 28044281 BACKGROUND

MeSH Terms

Conditions

Mental Fatigue

Condition Hierarchy (Ancestors)

Fatigue; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavioral Symptoms; Behavior

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The researcher responsible for data processing and statistical analyses was blinded to condition allocation. Due to the nature of the intervention, participants and the researcher supervising the experimental sessions could not be blinded.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, Group Head

Model Details: Participants completed a randomized, counterbalanced, crossover study consisting of two experimental conditions separated by a one-week washout period. In one condition, participants underwent a 30-minute mental fatigue induction protocol before a 30-minute daytime nap; in the control condition, participants completed the nap without the preceding mental fatigue protocol. Each participant served as his own control, and the order of conditions was randomized.

Study Record Dates

• First Submitted: April 28, 2026
• First Posted: May 12, 2026
• Study Start: January 11, 2021
• Primary Completion: May 15, 2021
• Study Completion: May 15, 2021
• Last Updated: May 12, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)