The Positive Ripple Effect of Training on Sleep and Stress Levels
Research shows improving diet and exercise cuts stress as effectively as dedicated stress therapy, without ever targeting it directly.
A nine-month randomised controlled trial published in PLOS One in March 2026 has found that a smartphone-assisted coaching program targeting diet and physical activity produced significant, lasting reductions in stress, comparable to a program that directly targeted stress itself, and also meaningfully improved sleep duration, even though neither stress nor sleep was explicitly addressed. The study, a secondary analysis of the Make Better Choices 2 (MBC2) trial, offers strong evidence that improving lifestyle behaviours like exercise and diet creates powerful "ripple effects" across the entire spectrum of health risk factors, potentially making it a scalable and cost-effective first-line approach for people carrying multiple lifestyle-related disease risks
Aim
Researchers wanted to know whether a behaviour change program explicitly targeting diet and physical activity would also produce collateral, “tag-along” improvements in stress and sleep — two domains the program never directly addressed.
This was a secondary analysis of the MBC2 trial data, designed to compare the cross-domain effects of a diet and activity intervention against a purpose-built stress and sleep intervention, to understand which program produced broader health gains.
Methods
The MBC2 trial was a 9-month, three-arm randomised controlled trial conducted across the Chicago area, enrolling 212 adults (mean age 40.8 years; 76% female; 59% non-white minority) who all displayed multiple lifestyle risk behaviours — specifically low moderate-to-vigorous physical activity (MVPA), low fruit and vegetable intake, high saturated fat intake, and high sedentary screen time.
All three arms used the same core delivery infrastructure: a custom smartphone app for daily self-monitoring and behavioural feedback, psychoeducational materials, telephone health coaching (weekly for the first 12 weeks, tapering to monthly by the end), and small monetary incentives for hitting goals. What differed was the target behaviour:
Diet/Activity group (two arms merged for this analysis): Targeted fruit and vegetable intake (≥5 servings/day), sedentary screen time (≤90 minutes/day), and MVPA (≥150 minutes/week)
Stress/Sleep group: Targeted a 30% reduction in perceived stress and achieving >7.5 hours of sleep per night, with daily relaxation exercises
Participants self-reported stress (11-point Likert scale, three times daily) and sleep duration (via morning smartphone questionnaire) across 7-day assessment windows at baseline, 3, 6, and 9 months. Data were analysed using linear mixed models to evaluate how each group’s outcomes changed over time.
Results
Stress: Both programs drove substantial, statistically significant reductions in daily stress over the 9 months, and critically, those reductions were statistically comparable between the two groups — meaning the diet and activity program reduced stress just as effectively as the program specifically designed to do so.
Stress/Sleep group: average stress score dropped by 2.08 points on the 11-point scale (P < 0.001)
Diet/Activity group: average stress score dropped by 1.68 points on the 11-point scale (P < 0.001)
The difference between groups was not statistically significant (P = 0.177)
Sleep: Both programs produced clinically meaningful improvements in sleep duration, but the Stress/Sleep program outperformed on this measure, which is expected, given that it directly targeted sleep.
Stress/Sleep group: estimated sleep duration increased by 92.65 minutes over 9 months (P < 0.001)
Diet/Activity group: estimated sleep duration increased by 26.39 minutes over 9 months (P = 0.002)
That 26-minute gain in the diet/activity group is notable in its own right: it was enough to shift the average participant from below the recommended 7–9 hours per night to within it, and was maintained across the full 9 months. The two groups followed different trajectories — the stress/sleep group improved rapidly from baseline to 3 months and then plateaued, while the diet/activity group showed a more gradual, sustained upward trend over the full study period.
Practical Takeaways
These findings have implications for anyone serious about long-term health and not just cardiovascular fitness:
Getting your exercise and diet in order may reduce your stress without trying. The diet/activity program matched the dedicated stress program for stress reduction. If you are managing stress, improving your food quality and moving more could be just as effective as specific stress-management techniques.
Cleaning up your lifestyle habits can add meaningful sleep time. An extra 26 minutes of nightly sleep from a diet and exercise program alone is a clinically significant gain — and it was sustained for nine months. You do not need a dedicated sleep program to meaningfully improve your sleep.
One intervention, multiple wins. Rather than stacking multiple intensive interventions (one for stress, one for sleep, one for diet), the data suggest a well-designed diet and activity program can deliver broad-spectrum improvements across several risk factors simultaneously, reducing burden, cost, and complexity.
Technology can make it scalable. Coaching was delivered remotely via smartphone and phone calls, which means this kind of approach is accessible well beyond a clinic setting - an important consideration given that half of American adults carry two or more lifestyle risk factors.
Sleep and stress were not required entry criteria. Participants were not selected because they had clinically severe sleep disorders or anxiety. Their baseline stress was moderate, and sleep was near the lower boundary of the recommended range. These results are most applicable to the broad, general population carrying subclinical lifestyle risks.
A key limitation worth noting: all outcomes relied on self-reported data via smartphone. No objective biomarkers (e.g., actigraphy for sleep, cortisol for stress) were used, which introduces some potential for reporting bias. Additionally, the sample was predominantly female (76%) and college-educated (69%), which may limit how broadly the findings apply.
Reference
Battalio, S. L., Spring, B., Wilson, E., Hedeker, D., & Pfammatter, A. F. (2026). Behavior change intervention targeting physical activity and diet improves stress and sleep. PLOS ONE, 21(3), e0343397. https://doi.org/10.1371/journal.pone.0343397
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