Winter wellness starts with sleep

“Sleep isn’t a luxury – it’s a foundational part of health and recovery.”

As the colder months settle in across Aotearoa, ExerciseNZ is encouraging Kiwis to take stock of their winter wellness – with a special focus on a crucial yet often overlooked pillar of health: sleep. Just three consecutive nights of restricted sleep (about 4.25 hours per night) can significantly alter blood biomarkers associated with cardiovascular disease. This is true even in young, healthy individuals, finds new research from Uppsala University in Sweden (published in Biomarker Research, April 2025).

Alarmingly, the study also found that regular physical activity does not offset these negative effects, making sleep more important than ever for those with fitness and wellbeing goals. “As winter rolls in and we shift our routines indoors, we want to remind people that sleep isn’t a luxury – it’s a foundational part of health and recovery,” says Richard Beddie, CEO of ExerciseNZ. “Quality sleep might just be the secret weapon for smashing your fitness goals this winter.” While many Kiwis double down on exercise to combat seasonal lethargy, the combination of colder temperatures, darker days, and disrupted sleep patterns can actually hinder performance and recovery.

In fact, research published in the Journal of Functional Morphology and Kinesiology shows that sleep loss can impair muscle glycogen repletion, reduce time to exhaustion, and decrease strength and aerobic capacity — all of which can compromise training outcomes. The study underscores how sleep enhances performance, cognitive functioning, and outcomes across one-repetition maximum testing, endurance training, and high-intensity interval workouts

The science of sleep and exercise:
Why recovery matters more in winter
• Restricted sleep increases levels of inflammation related proteins in the blood, raising the risk for cardiovascular issues, even in fit, active people.
• Sleep plays a key role in muscle repair, hormone regulation, and mental clarity – all essential to getting the most from your workouts.
• A consistent sleep routine can reduce injury risk, support immunity during colder months, and enhance energy levels for winter training