Overview
- An Open Heart trial in 134 adults with cardiovascular risk tested 40‑minute brisk treadmill walks five days a week for 12 weeks at times aligned or misaligned with each person’s chronotype.
- Participants who trained in sync with their body clock cut systolic blood pressure by about 10.8 mm Hg on average versus 5.5 mm Hg when out of sync, with larger gaps in those with hypertension.
- Aligned training also produced lower fasting glucose and LDL cholesterol, higher aerobic capacity, better heart‑rate variability, and bigger gains in sleep quality.
- Researchers warn that “social jet lag” — living on a schedule that clashes with your internal clock — can dull exercise payoffs by forcing the body to work against daily hormone and metabolism cycles.
- A separate review reports evening exercise may help glucose control in type 2 diabetes, and experts urge simple chronotype screening to tailor advice while noting the trial was short and used one exercise type.