# Exercise, RHR & energy: what the research actually says

Exercise improves sleep, sleep improves exercise, and the loop can be started from either end — the basis of the 5·4·3·2·1 rule.



## All studies

- **Effects of evening exercise on sleep in healthy participants: a systematic review and meta-analysis** — Stutz J, Eiholzer R, Spengler CM (2019), Sports Medicine 49(2):269–287. Evening exercise does not harm sleep — unless vigorous exercise ends within ~1 h of bedtime.

- **Effects of exercise on the resting heart rate: a systematic review and meta-analysis of interventional studies** — Reimers AK, Knapp G, Reimers CD (2018), Journal of Clinical Medicine 7(12):503. Endurance training lowers resting heart rate by ~5 bpm on average; yoga also lowers it.

- **The effects of physical activity on sleep: a meta-analytic review** — Kredlow MA, Capozzoli MC, Hearon BA, Calkins AW, Otto MW (2015), Journal of Behavioral Medicine 38(3):427–449. Regular exercise modestly improves total sleep, efficiency and deep sleep.

- **The bidirectional relationship between exercise and sleep: implications for exercise adherence and sleep improvement** — Kline CE (2014), American Journal of Lifestyle Medicine 8(6):375–379. Better sleep → more exercise → better sleep: a loop worth starting anywhere.

- **Association between objectively-measured physical activity and sleep, NHANES 2005–2006** — Loprinzi PD, Cardinal BJ (2011), Mental Health and Physical Activity 4(2):65–69. 150 min/week of moderate-vigorous activity was associated with ~65% better odds of feeling well rested.

- **Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping** — Milner CE, Cote KA (2009), Journal of Sleep Research 18(2):272–281. Short (10–20 min) early-afternoon naps improve alertness with little sleep inertia; long/late naps cut into night sleep.

- **Effects of chronic exercise on feelings of energy and fatigue: a quantitative synthesis** — Puetz TW, O'Connor PJ, Dishman RK (2006), Psychological Bulletin 132(6):866–876. Across 70 trials, regular exercise reliably increased feelings of energy and reduced fatigue — Galpin's 'stress inoculation'.

- **The post-lunch dip in performance** — Monk TH (2005), Clinics in Sports Medicine 24(2):e15–e23. The early-afternoon dip is a normal circadian feature, largely independent of lunch — 'that's the point'.

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Educational summary of published research, not medical advice. Screening scores are not diagnoses. If a score is elevated or you feel unwell, talk to a clinician.

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