Effects of Exercise Timing on Sleep Quality (SLEEPCORE)

Effects of Exercise Timing and Physical Activity Level on Sleep Quality and Body Temperature

Modern lifestyles are marked by a prevalence of sedentary behaviors and physical inactivity, which have been linked to numerous adverse health effects. While regular physical exercise is a well-established countermeasure, exercising in the late afternoon may paradoxically disrupt deep sleep due to increased core body temperature. Inactive and sedentary individuals, who often have impaired autonomic function compared to endurance-trained athletes, may be particularly susceptible to these negative effects, potentially resulting in compromised thermoregulation and exacerbated disruptions to deep sleep, a critical stage of sleep essential for overall recovery. Therefore, this study aims to investigate the impact of aerobic exercise performed in the late afternoon versus morning on: 1) deep sleep and sleep onset latency; and 2) core body temperature and its autonomic regulatory mechanisms on endurance-trained and inactive-sedentary people.

Study Overview

• Status: Recruiting
• Conditions: Healthy Endurance Athlet; Inactive People
• Intervention / Treatment: Other: Aerobic Exercise

• Study Type: Interventional
• Enrollment (Estimated): 42
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Frédéric ROCHE, PhD; Phone Number: 33 0477828695; Email: frederic.roche@univ-st-etienne.fr

Study Locations

• France
  • Saint-Etienne, France, 42055
    • Recruiting
    • CHU Saint-Etienne
    • Sub-Investigator: David HUPIN, MD
    • Sub-Investigator: Léonard FEASSON, PhD
    • Sub-Investigator: Clément FOSCHIA, MD
    • Sub-Investigator: Philippe BOIRON, MD
    • Contact: Florian CHOUCHOU, Ph.D. student; Phone Number: 33 4 77 12 03 04 77 12 03 83; Email: florian.chouchou@univ-reunion.fr
    • Contact: Léonard FEASSON, PhD; Phone Number: 33 4 77 12 03 04 77 12 03 83; Email: leonard.feasson@univ-st-etienne.fr
    • Principal Investigator: Frédéric ROCHE, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Group "Inactive" :No regular exercise practice (inactive people that don't follow the WHO recommendations) and have sedentary behaviors
• Group "Active": Regular exercise (athletes that are specialized in aerobic exercise, with more than 300 minutes per-week over 6 months and practice at regional level).

Exclusion Criteria:

• Have sleep disorders medically diagnosed or detected by sleep forms cutoffs (clinical insomnia by ISI, severe risk of obstructive sleep apnea by Stop-Bang, bad sleep quality by PSQI.
• Have a diagnosed mental health condition requiring treatment
• Have renal, respiratory, cardiovascular or neuromuscular disease medically diagnosed.
• Be pregnant or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: "Inactive-sedentary" group; inactive participants that realize 3 experimental conditions: evening exercise, morning exercise and control (no-exercise).	Other: Aerobic Exercise; The exercise consists of running on a treadmill at 90% of maximum aerobic speed (MAS) for 30 minutes, followed by 12% increments every 5 minutes, until exhaustion (a "time-to-exhaustion" type of exercise).
Experimental: "Active" group; endurance athletes that realize 3 experimental conditions: evening exercise, morning exercise and control (no-exercise).	Other: Aerobic Exercise; The exercise consists of running on a treadmill at 90% of maximum aerobic speed (MAS) for 30 minutes, followed by 12% increments every 5 minutes, until exhaustion (a "time-to-exhaustion" type of exercise).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of deep slow-wave sleep	Evaluation of the duration of deep slow-wave sleep (N3 stage) quantified by the EEG signal from polysomnography (Nox A1, Resmed®, USA).	Once a month for 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of core temperature	Assessment of core temperature until the end of the sleep period will be measured using gastrointestinal telemetric pills (eCelsius, Bodycap®, France).	Once a month for 3 months
Evaluation of autonomic nervous system thermoregulation	Evaluation of autonomic nervous system thermoregulation through time-domain (R-R intervals in ms)	Once a month for 3 months
Evaluation of autonomic nervous system thermoregulation	Evaluation of autonomic nervous system thermoregulation through frequency- domain parameters (in Hz)	Once a month for 3 months
Complementary sleep evaluation	Complementary sleep evaluation through analysis of duration of N1, N2, and REM stages (in Percentage of Total Sleep Time)	Once a month for 3 months
Complementary sleep evaluation	Complementary sleep evaluation through characteristics of slow waves present in N3 (amplitude in microvolts)	Once a month for 3 months

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Saint Etienne
• Investigators: Principal Investigator: Frédéric ROCHE, PhD, Centre Hospitalier Universitaire de Saint Etienne

Study record dates

Study Major Dates

• Study Start (Actual): January 23, 2026
• Primary Completion (Estimated): January 31, 2029
• Study Completion (Estimated): May 31, 2029

Study Registration Dates

• First Submitted: November 21, 2025
• First Submitted That Met QC Criteria: December 22, 2025
• First Posted (Actual): January 7, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: sleep quality; exercise timing; endurance athletes
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Initiation and Maintenance Disorders; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: 25CH122; 2025-A00957-42 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: This study is realized only in St-Etienne university Hospital

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No