How To Make Exercise Even Better For Your Heart And Sleep

You might have heard of “chronotypes”, or a person’s natural body clock that determines whether they’re a night owl or an early bird.

That’s usually mentioned in relation to sleep. But a new randomised controlled trial suggests that it might impact our peak workout time, too.

Published in the BMJ journal OpenHeart, the research found that, “Aligning exercise timing with individual chronotype significantly enhances cardiometabolic and sleep-related outcomes in at-risk adults.”

What did the research show?

The scientists conducted a 12-week trial in which 150 sedentary participants, aged 40-60, had their chronotype assessed with a questionnaire.

The participants were split into groups, including a chronotype-aligned exercise (CAE) group, who worked out when best suited their chronotype, and a chronotype-misaligned exercise (CME) group, who exercised outside of their natural “best” time.

Participants completed five 40-minute moderate-intensity sessions a week for the duration of the trial. Researchers measured their blood pressure, heart rate variability, blood sugar, LDL cholesterol levels, sleep quality, and oxyegn use.

The reduction in blood pressure in the CAE group was “substantial and significantly greater than in the CME group,” the paper reads.

“Aligning exercise timing with individual chronotype significantly enhances cardiometabolic and sleep-related outcomes in at-risk adults.”

You likely already know whether you’re a night owl (late chronotype) or an early bird (early chronotype).

“Early chronotypes benefited more from morning exercise, while late chronotypes showed better results with evening sessions,” the study reads.

However, this research noted that all exercise, even that which is done outside of your chronotype, reduces the risk of heart health issues.

Dr Jeffrey Kelu, a research associate at King’s College London, told the Science Media Centre: “This is a useful and important study because it brings personalised medicine into a very practical context by asking not only what intervention to prescribe, but also when to prescribe it”.

They added, “Importantly, even the misaligned group improved, so the broader public-health message remains that any exercise is worthwhile, while timing it to biological preference may offer an additional benefit.”