Scientific Programme
Sports and Exercise Medicine and Health
IS-MH14 - Exercise Time, Frequency and Dose: Rethinking Movement Across the Lifespan
Date: 10.07.2026, Time: 11:00 - 12:15, Session Room: Auditorium B (STCC)
Description
Emerging evidence suggests that timing and patterning of behaviors (e.g. eating, sleep, and physical activity) impact cardiometabolic and vascular health outcomes, with implications for implementation in real-world routines. For example, physical activity is a cornerstone of health promotion and disease prevention, yet current recommendations rarely address two underused levers: when we move (i.e. timing of activity bouts) and how we accumulate it (i.e. frequency and duration of activity bouts). This symposium will integrate mechanistic, translational, and population perspectives to build a practical “precision daily activity” framework for different populations.
Chair(s)
Nanna Ýr Arnardóttir
University of Akureyri, Nursing
Iceland
Speaker A
Audrey Bergouignan
The Hubert Curien Pluridisciplinary Institute, French National Centre for Scient
France
Read CVECSS Lausanne 2026: IS-MH14 [41450]
One Long or Many Short? Activity Bout Structure, Sedentary Breaks, and Cardiometabolic Health
Background: Many adults fail to meet recommended exercise targets, but may be able to accumulate short, distributed bouts and sedentary breaks across the day. Do these patterns deliver benefits equivalent to - or distinct from, a single continuous session? Aims: (i) Compare acute and chronic effects of continuous vs accumulated activity on glycemia, lipemia, blood pressure, and appetite; (ii) evaluate the added value of interrupting sedentary time; (iii) outline adherence-friendly algorithms that align dose with goals and constraints. Approach: Drawing on controlled lab studies and free-living trials, I will synthesize evidence on bout structures such as 1x45 or 9×5 min, hourly 2–5-min movement snacks, and staircase or walking-call routines. Outcomes include, energy balance, substrate use, postprandial lipids, ambulatory BP, insulin sensitivity (clamps/HOMA-IR), glucose control (OGTT, CGM metrics), feeding behaviour, NEAT, self-reported adherence, and barriers and facilitators to the interventions. Key Evidence: Frequent micro-bouts of activity and sedentary interruptions produce greater improvements in glycemic homeostasis, BP, blood lipids, and others relative to their small time cost, likely via repeated GLUT4 translocation pulses, endothelial shear stress spikes, and autonomic “mini-resets.” In addition, they seem not to trigger the typical behavioural compensations observed in response to single continuous bouts of MVPA (i.e., a decrease in daily movement and an increase in sedentary time), thus favouring energy balance and body mass. Accumulated MVPA can match continuous sessions for some cardiometabolic markers when total dose and intensity zones are comparable. Implementation in schools and workplaces enhances reach and equity. Translation—Decision Guide: • Primary goal glycemia/lipids → distribute movement (2–5 min each 30–60 min; add 3×10 min brisk walks); • Primary goal BP → micro-bouts across the workday + 1–2 moderate sessions/week; • Primary goal fitness → maintain distributed breaks plus ≥2 sustained sessions (≥20 min) at target intensity; • Weight management → pair distributed movement with appetite monitoring to minimize intake compensation. Gaps & Priorities: Clarify dose equivalence thresholds, minimal effective “snack” duration, long-term weight outcomes, and interactions with sleep and meal timing. Conclusion: “Many short” is a potent, scalable strategy for metabolic health and adherence. A blended architecture (micro-bouts + 1–2 sustained sessions/week) covers most goals with exceptional feasibility.
Speaker B
Josiane Broussard
Colorado State University, Department of Health and Exercise Science
United States
Read CVECSS Lausanne 2026: IS-MH14 [41457]
Does When We Exercise Matter? Circadian Mechanisms and Metabolic Payoffs
Background: Despite clear benefits of regular physical activity, current guidance rarely considers timing of exercise. Yet circadian biology plays critical roles in glucose regulation, lipid metabolism, vascular tone, sleep pressure, and performance, implying that the same exercise dose may yield different physiological payoffs depending on when it is performed. Aims: (i) Synthesize mechanistic and human evidence that timing of behaviors including eating and exercise modulates metabolic responses; (ii) compare morning vs evening prescriptions for glycemia, lipids, blood pressure, and sleep; (iii) translate findings into pragmatic guidance for diverse schedules, including shift work. Approach: In this presentation, I will integrate laboratory trials and free-living interventions that manipulate time of day of both eating and exercise and observe outcomes spanning glycemic control (OGTT/CGM indices), lipid handling (postprandial TG, HDL function), autonomic and vascular markers (HRV, BP dipping), and sleep quantity/quality. Evidence is interpreted through the lens of central/peripheral clocks, zeitgeber interactions (light, meal timing, sleep), chronotype, and sex. Key Evidence: Morning exercise often favors fasted-state fat oxidation and BP reduction, while evening sessions may enhance 24-h glycemic stability and performance via circadian peaks in muscle function and temperature. In metabolic syndrome and shift-work contexts, targeted timing can offset misalignment. Preliminary free-living trials indicate that timing-consistent prescriptions improve adherence and sleep regularity when paired with simple routine anchors (meal timing, light exposure). Translation: Right-Time Playbook: • Primary goal glycemia → favor late-afternoon/evening or post-meal walking; • Primary goal BP/sleep → morning or early-day sessions, avoid late-night high intensity; • Shift workers → stabilize anchor sleep/wake, then place short to moderate bouts in biological daytime; Gaps & Priorities: Determine timing×dose equivalence, durability beyond 12–24 weeks, interaction with chrono-nutrition, and personalization by chronotype and sex. Trials should incorporate CGM, ambulatory BP, sleep staging, and adherence metrics. Conclusion: Timing is a modifiable multiplier of exercise benefits. Embedding circadian principles into everyday prescriptions can improve metabolic outcomes with minimal added cost or complexity.
Speaker C
Erlingur Johannsson
University of Iceland, Center for research in sport and health sciences
Iceland
Read CVECSS Lausanne 2026: IS-MH14 [7994]
Physical Activity Across the Lifespan: Insights from Iceland’s 1988 Birth Cohort
Background: Life-course approaches suggest that when and how activity is established and re-established during key transitions in childhood and early adulthood shapes mid-life health. The study of the 1988 cohort provides a unique opportunity to follow the same individuals at three time points, using extensive data collection that examines the health of this group from multiple angles. Aims: (i) Characterize trajectories of physical activity from adolescence to early adulthood (age 15, 23 and 36) (ii) examine associations with cardiometabolic, mental-health, and sleep outcomes; (iii) identify actionable areas for schools, workplaces, and municipalities, including timing-sensitive approaches suited to environments with extreme daylight variation. Approach & Data: Using repeated self-report and accelerometry based measures of PA and sleep (where available), linked with clinical markers (BMI, blood pressure, CRF), psychosocial variables (education, SES, social support), and environmental context (urban/rural, daylight), we apply trajectory modeling and cluster analyses (e.g., consistently active, decliners, late adopters). Effect modification by sex, occupation (including shift work), and season will be evaluated. Key Findings to Synthesize: • Distinct activity trajectories map onto mid-life cardiometabolic risk, sleep regularity, and psychological well-being. • Critical transitions: school→work, parenthood, and winter→summer shifts — coincide with inflection points where brief interventions (e.g., micro-bouts at work, active transport, post-meal walks) may yield sustained change. • In high-latitude contexts, timing (daylight-aligned opportunities) and bout structure (short, frequent movement during dark months) can buffer sedentary accumulation and mood variability. Translation & Policy: We outline timing-aware, low-barrier strategies for schools (movement “snacks” each class block), workplaces (hourly breaks, walking meetings), and municipal design (well-lit winter walking loops). For late adopters, “catch-up” trajectories demonstrate that meaningful gains are achievable in the third and fourth decades when frequency and timing are prioritized over long, continuous sessions. Gaps & Next Steps: Expand device-based measurement at subsequent waves; integrate causal inference (target-trial emulation) to strengthen policy guidance; evaluate equity impacts across neighborhoods and work life. Conclusion: The 1988 cohort suggests that patterns of movement from adolescence to early adulthood, may be associated with health outcomes. Considering timing and activity patterns in life-course policy could help improve reach, adherence, and outcomes in Iceland and elsewhere.