Fitness

How exercise resets your body clock and improves sleep patterns

Published

3 months ago

February 5, 2025

How exercise resets your body clock and improves sleep patterns

Exercise improves sleep quality and helps treat sleep disorders by regulating circadian rhythms, reducing stress, and enhancing physiological functions like melatonin production and autonomic balance.

Review: The impact of exercise on sleep and sleep disorders. Image Credit: Lysenko Andrii / Shutterstock

In a recent review article published in the journal npj Biological Timing and Sleep, researchers summarized the research on how exercise, or structured physical activity, improves sleep quality, both for those with sleep disorders and healthy individuals. They highlighted that the effects of exercise on sleep are influenced by factors such as an individual’s age, sex, fitness level, and the type, timing, and intensity of exercise.

Types of Exercise

Exercise is any form of repetitive, planned, and structured physical activity. Aerobic exercise involves activities that use the body’s large muscle groups, increasing the heart rate and the amount of oxygen a person uses. Swimming, cycling, and walking are forms of aerobic exercise.

While aerobic exercise improves cardiovascular health, anaerobic exercise, which includes sprinting and weight training, builds muscle strength and mass. Meanwhile, stretching exercises focus on improving an individual’s range of motion, but the evidence is mixed regarding whether or not they can prevent injuries.

Dynamic exercise involves moving joints and appears to have health benefits in the long term, including improved blood flow and lower blood pressure. However, static exercise occurs when muscles are activated without movement and can increase blood pressure significantly but build strength over time. The journal article also noted that these different forms of exercise may have distinct effects on sleep, with aerobic exercise generally providing the most benefits for sleep quality.

Advantages of Exercise

Exercise is critical to regulating weight, as it prevents excessive gain and can support weight loss by burning calories and balancing calorie expenditure and intake. It decreases the risk of diabetes, hypertension, and depression. Regular exercise also improves cardiovascular health, improves heart recovery, and decreases the resting heart rate.

Beyond physical benefits, exercise also improves mood and energy. It increases energy levels by improving the delivery of nutrients and oxygen to the tissues. Meanwhile, exercise improves mood, reduces stress, and enhances relaxation, particularly if it takes the form of activities that a person enjoys. Research has shown that exercise can reduce levels of cortisol, a stress hormone linked to sleep disturbances, while increasing melatonin, the hormone that regulates sleep cycles.

Not getting adequate amounts of exercise has been linked to chronic illnesses such as diabetes, cancer, and heart disease, which have become leading causes of global mortality.

How Exercise Improves Sleep

In healthy individuals, exercise improves sleep efficiency, which is defined as the ratio of time a person spends sleeping to the total time they spend in bed.

Specifically, exercise between four and eight hours before going to bed can reduce wakefulness during sleep and help people fall asleep faster. However, the review emphasized that exercising less than four hours before bedtime may delay melatonin release and increase body temperature, potentially making it harder to fall asleep. Regular exercise also improves overall sleep quality and helps people sleep longer.

Over time, exercise improves sleep hygiene, namely the habits that help people sleep well. This leads to stable sleep-wake cycles and improves the regulation of the body’s circadian rhythms. Because exercise acts as a “zeitgeber” (a factor that influences the body’s biological clock), it can help reset disrupted circadian rhythms, particularly in individuals who experience sleep disturbances due to shift work or jet lag.

Exercise can also indirectly improve sleep by reducing stress and enhancing mood. Regular and consistent exercise reduces stress, depression, and anxiety. By reducing the heart rate, exercise calms the body, facilitating sleep. It also regulates hormones like cortisol and melatonin, which are linked to sleep patterns.

Treating Sleep-Related Disorders

Researchers have studied the benefits of exercise for alleviating sleep disorders. Exercise has psychological benefits, reducing the emotional stress and anxiety associated with disordered sleep. It can also reduce sleep-disordered breathing and improve autonomic and hormonal imbalances that worsen sleep quality.

Regarding specific sleep disorders, people experiencing insomnia can benefit from moderate-intensity aerobic exercise, which improves the onset of sleep, reduces the time spent awake, and enhances the overall sleep quality. The review also noted that exercise may be more effective when combined with sleep hygiene interventions, such as maintaining a consistent bedtime and avoiding stimulants before sleep.

Another condition that can hamper sleep quality is restless leg syndrome (RLS), a neurological condition that causes an uncontrollable urge to move the legs. Aerobic exercise can also reduce symptoms of RLS, including throbbing, aching, and itching in the legs. The study highlighted that the benefits of exercise for RLS may be due to improved blood circulation and neuromuscular function.

For people with sleep apnea, which causes breathing to stop and start repeatedly during sleep, researchers recommend combining weight loss with exercise to reduce the severity of the condition and improve functioning and wakefulness during the day. Importantly, the review found that even in the absence of significant weight loss, regular exercise can improve sleep apnea symptoms by enhancing autonomic nervous system regulation and reducing inflammation.

Conclusions

While existing studies on the relationship between exercise and sleep are promising, researchers identified ways to apply these findings and avenues for future investigations.

Long-term studies are needed to understand how different durations, intensities, and types of exercise impact sleep patterns. Diverse populations should be included to identify tailored and effective interventions for different demographic groups. The review also called for more research into the molecular mechanisms underlying the effects of exercise on sleep, such as its impact on brain function and immune responses.

There is still much that is not known about the physiological mechanisms that underpin exercise’s impacts on sleep quality and circadian rhythms, particularly among those with chronic sleep disorders. The systemic and molecular effects of exercise on sleep also need more exploration.

Current research can be applied to interventions to improve the health of athletes and the general public. For athletes, optimizing sleep is crucial for recovery and performance, and the review suggested integrating personalized sleep-monitoring protocols into training programs.

Physical activity should be promoted as a non-pharmacological intervention for the general public, but clear guidelines regarding intensity, frequency, and timing should be provided for different age groups. The researchers stressed the importance of personalized exercise prescriptions that account for an individual’s age, fitness level, and existing sleep disturbances to maximize benefits.

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Fitness

The worst time to exercise for a good night’s sleep

Published

5 hours ago

May 16, 2025

Press Room

The worst time to exercise for a good night’s sleep

Need a good night’s sleep? Cut back on exercising in the evening.
Getty Images

If you’d like to sleep well tonight, you should probably avoid exercising this evening, especially if your workout will be intense.

That’s the takeaway from a new study of almost 15,000 active men and women. It found that exercising within about four hours of bedtime makes it harder to fall asleep and reduces how long you spend slumbering by as much as 43 minutes.

The effects were most pronounced when workouts were long, intense or both, but almost any evening exercise influenced how well people slept.

“I do my best now to avoid exercising late in the evening,” said Josh Leota, a researcher at Monash University in Australia, who led the new study.

But there may be ways to minimize the effects if evening happens to be the only time you can — or care to — work out.

The link between exercise and sleep

For decades, researchers have been puzzled by the relationship between sleep and exercise. According to most past research, active people sleep better than the sedentary, but not always. Some studies suggest morning workouts improve sleep, while later workouts don’t, but others seem to show any movement, at any time, helps people nod off earlier.

Most of these studies have been quite small, though, often involving fewer than 20 volunteers, and relied on people’s memories of when and how they worked out and snoozed.

So for the new study, published in April in Nature Communications, researchers at Monash teamed up with the activity-tracker maker Whoop to parse anonymized data from 14,689 men and women aged 18 to 87 who’d worn a Whoop tracker for at least a year. (Whoop provided access to the data but “did not have any input into the analysis or results,” Leota said.)

The records included extensive details about when and how intensely people exercised every day, based on their heart rates, and also how well they’d slept that night, including when they’d nodded off, how long they’d remained asleep and the overall quality of their slumber.

36 extra minutes to fall asleep

The researchers were interested in how late-day exercise changes sleep — since previous studies had so often disagreed with one another. They first categorized people’s workouts as light, moderate, hard or maximal, corresponding, in broad terms, to a brisk walk, easy jog, long run or prolonged high-intensity interval training. They also took note of when people worked out and mapped their sleep.

Then they cross-checked. Did people sleep better or worse after they worked out close to bedtime? What if the exercise was gentle? What if they pushed themselves?

The answers consistently showed that “later exercise timing and higher exercise strain” were each strongly linked to worse sleep, the scientists wrote in the study. Even relatively modest evening workouts, such as light weight training or a gentle gym class, could somewhat disrupt sleep.

But the impacts intensified along with the intensity. If people ran an after-hours half-marathon or played a rousing late-night soccer, hockey or basketball game within about two hours of their usual bedtime, they needed an average of 36 extra minutes to fall asleep.

Finish that same strenuous exercise even later at night, after someone’s usual bedtime by an hour or two, and he or she would need an extra 80 minutes to doze off.

People also slept less, in total, after hard, evening exercise, and the quality of their sleep declined, with frequent waking, tossing and turning.

How to wind down after a late workout

The researchers didn’t look at why this happens, but they suspect people were too wound up, physiologically. Participants’ tracker data showed their heart rates were still elevated hours after strenuous evening exercise, while, at the same time, their heart rate variability, which should be somewhat high, remained stubbornly low.

In essence, Leota, said, people got too pumped up by vigorous, late-night workouts to easily drift off or stay asleep. “A basic rule of thumb,” he said, “is the harder you work out, the more time you need to give yourself to recover before going to sleep.”

If you do need to exercise late in the evening, you might want to try meditation, gentle yoga or other relaxation techniques afterward to calm your revved-up body, Leota said.

Even better, “if you can exercise earlier in the day, that would be preferable,” he said.

But if the evening is your best option, stick with it. “We are definitely not discouraging exercise,” Leota said. “For the vast majority of people, any exercise is better than no exercise. We would just recommend trying to finish as early as possible or opting for lighter workouts.”

Fitness

Exercising during your period — what to do and what to avoid, according to experts

Published

22 hours ago

May 15, 2025

Press Room

Exercising during your period — what to do and what to avoid, according to experts

For anyone who menstruates, you’ll know that your hormones can affect how you feel at different times in your cycle. However, did you know these hormones can also impact your athletic performance? If you didn’t, you’re not alone — a 2019 study conducted by researchers at St Mary’s University in Twickenham, England, analyzed more than 14,000 female Strava members. 72 percent of women said they have never received any education regarding exercise and their menstrual cycle.

Women’s Health Week

This article is part of Tom’s Guide’s Women’s Health Week — a series of content that explores how technology and the right workouts can support and empower women through every phase of life.

If you have a ‘normal’ menstrual cycle — the monthly process where the rise and fall of certain hormones prepares your body for a possible pregnancy — then you will have, on average, 450 periods throughout a lifetime. So, it makes sense to understand what’s happening in your body and how movement can help. Research has continually found that exercise can help to beat a bad mood and even boost dwindling energy levels.

You might have heard about exercise cycling, but below we spoke to the experts on how best to exercise during your period.

The menstrual cycle — a breakdown

Although the average length of a menstrual cycle is 28 days, it can be anywhere between 21 to 35 days long.

Chloe Thomas, a personal trainer, women’s health and mindset coach, and the founder of Chloe Inspires Coaching explains, “The first day of your period bleed is day one of your cycle. This is when the hormones progesterone and oestrogen are at their lowest.”

Next is the follicular phase, which begins once your period ends. “Here, oestrogen is starting to rise again, which is why you typically have more energy,” says Chloe.

Around halfway through your cycle, you enter the ovulation stage of your cycle. This is the shortest phase, but it is when you usually feel your best, as oestrogen peaks and the luteinising hormone surges. The surge of luteinising hormone causes the release of an egg from the ovary, known as ovulation. The egg travels down the fallopian tube towards the uterus.

“You may feel confident, strong, and focused with a high libido,” adds Chloe. Ovulation is the most fertile point of the menstrual cycle.

After ovulation, you’ll enter the luteal phase. “This is when the hormone progesterone starts to rise and oestrogen starts to drop. You’ll experience tiredness, cravings, bloating, and mood swings too,” explains Chloe. If no pregnancy has taken place, progesterone and oestrogen levels drop, triggering the start of menstruation. Then, the cycle begins again.

“It’s important to note that we are all different and have different levels of hormones. Some women are more affected by Premenstrual Syndrome (PMS) than others for example,” says Chloe.

(Image credit: Shutterstock)

How to exercise during your period

1. Don’t chase PBs

Hoping to lift your heaviest deadlift on day one of your period? While some women might find this easy, for others, bleed week is not a time for hitting those personal bests.

Sarah Campus, a women’s personal trainer, nutrition coach, and founder of LDNMUMSFITNESS says: “Most women feel slightly weaker or less energised during the first couple of days of their period due to low oestrogen and progesterone. Plus, because you’re losing blood, you’re losing iron, which can impact endurance and strength, especially if your iron levels are already low.”

Periods can also affect your sleep and mood, which can also make you feel weak and off your game.

A study in the journal Sports Medicine found that muscle strength is highest in the days following a period, so letting your body rest for a few days is no bad thing. You’ll come back stronger, ready to smash those big lifts!

2. Prioritize low-impact workouts

If you’re feeling tired than usual during your period week, try walking, yoga, Pilates, or even gentle cycling. These low-impact ways to move require less energy than higher-intensity exercise.

If you feel up to it, you can stick to a weight training plan, but Chloe explains that for some women, working with lower reps and using lighter weights might be more comfortable, especially during day one and two of your period.

Chloe adds, “I focus on progressive overload (gradually making workouts harder by increasing weight) in the follicular phase in the lead up to ovulation. I push hard with my sessions and weights, and I do more intense cardio workouts during this phase.”

3. Always warm up and cool down

It’s easy to skip the pre-exercise warm-up and the post-exercise cool-down, but during your period, they are more important than ever, as your muscles and joints will likely feel tighter and stiffer.

Sarah says that during menstruation, your body goes through changes that could affect how you move and recover. “Lower oestrogen levels mean less joint lubrication, which can lead to stiff joints. Prostaglandins — hormone-like chemicals released to help shed the lining of the uterus, which causes a period, can cause cramps, inflammation, and fatigue too.”

Research in the American Journal of Sports Medicine found that hormone levels have an impact on knee joint laxity, with greater levels of stiffness occurring during the early parts of the cycle and decreased stiffness occurring during ovulation.

“Prioritise warm-ups and cool downs and spend extra time warming up to get blood flowing and prepare your muscles and joints,” says Sarah. “Gentle stretching or foam rolling after exercise will help reduce tension and help you to recover.”

But it’s not all bad news, as while you might feel stiffer and more tired during your period week, your chances of actually developing an injury are lower during menstruation. Research from UCL, the University of Bath, and St. Mary’s University found that female football players were six times more likely to experience a muscle injury in the days leading up to their period compared to when they were on their period.

4. Eat right

The foods you eat during your cycle, including your period, can have an impact on how you feel. Research has found that heavy periods can lead to a greater amount of lost iron, which is the most frequent cause of iron-deficient anaemia, where your body doesn’t produce enough red blood cells because the level of iron in your blood is too low.

“You lose iron through menstrual bleeding, which can leave you feeling tired, dizzy, or weaker during workouts. Low iron equals less oxygen delivery to muscles, which in turn can lead to fatigue. Eat red meat, chicken, turkey, spinach, kale, broccoli, and lentils,” says Sarah.

Enjoy magnesium-rich foods too, such as bananas, dark chocolate, leafy greens, pumpkin seeds, and crunchy almonds. “Magnesium helps with muscle relaxation, reducing cramps and helping to beat bloating or water retention,” says Sarah.

Research has found that a combination of 250 milligrams of magnesium plus 40 milligrams of vitamin B6 could help decrease PMS symptoms. These symptoms don’t just occur before your period week, but they can linger on during menstruation too. Find vitamin B6 in foods such as chicken, salmon, sweet potatoes, and avocados.

Although your period cravings might be screaming out for sugary foods, Sarah says that too many sugary snacks can cause blood sugar spikes and crashes, which can leave you feeling irritable and lacking in energy, making exercise even harder.

Ultimately, exercising during menstruation involves listening to your body. For some women, taking it easy and doing light, relaxing exercises such as stretching and yoga might be more preferable. For others, PMS might not be an issue, and exercise can continue as normal.

Either way, understanding your hormones and your cycle, and taking rest when you need, could help you to come back stronger, fitter, and quicker.

Fitness

Where Movement Meets Meaning: The story behind Vault Strength Club’s community-first fitness culture

Published

2 days ago

May 14, 2025

Press Room

Where Movement Meets Meaning: The story behind Vault Strength Club’s community-first fitness culture

Founded in April 2024, Vault Strength Club (VSC®) is redefining wellness culture in South Africa. Born from a desire to create more than just a fitness group, VSC® blends movement, lifestyle, and meaningful connection into one inclusive, empowering community. From humble Saturday runs to collaborations with major brands and dynamic events, the club has rapidly grown into a thriving hub where fitness meets friendship, and every member plays a vital role in the journey

What inspired you to start your community, and what’s your vision for VSC®?

Vault Strength Club (VSC®) was founded in April 2024 out of a desire to create an inclusive space that combines fitness, lifestyle, and meaningful connections. I’ve always been passionate about building communities that offer more than just physical activity, it’s about creating a movement where individuals can connect, grow, and elevate one another. Our vision is to redefine wellness culture in South Africa, curating a space where fitness, social connection, and personal development intersect.

Vault Strength Club

How has VSC® evolved over time, and what significant milestones have you achieved?

What started as casual Saturday runs quickly evolved into a thriving community. In under a year, we’ve celebrated several milestones, building a consistent, committed community that shows up weekly. Hosting successful collaborations and events with leading brands and organizations such as Under Armour, Women’s Warehouse Charity Foundation, 247 Represent, LITA Water, Revive Electrolytes, Raising Queens Foundation, Red Bull to name a few, Launching our own merchandise line to further solidify our identity and expanding into fitness-focused events like padel tournaments, hikes, and social gatherings to deepen engagement.

How do you foster a sense of community and camaraderie among your members?

We are intentional about creating an inclusive and supportive space. Beyond our weekly runs, we host padel tournaments, celebrate members’ weekly achievements by checking their stats and awarding their efforts every Saturday, and encourage members to support each other throughout the week. Our leadership team ensures that every individual feels like a valued part of the movement.

What are some of the biggest challenges facing fitness communities in South Africa, and how do you address them?

Key challenges include safety, inclusivity, and accessibility. Running and fitness spaces can sometimes feel intimidating, which prevents new participants from joining. We deliberately foster a non-judgmental environment where everyone feels welcome. Additionally, safety is paramount, whether during our runs or the larger events we host with brand partners and organizations. We prioritize ensuring our members feel secure at all times and making sure nobody gets left behind

What’s your take on people saying fitness communities have become the dating site of their dreams, has your community had some blooming love?

At VSC®, our focus is on fostering meaningful relationships rooted in fitness, friendship, and collaboration. We’ve seen strong friendships, partnerships, and professional opportunities develop within our space. Our goal is to cultivate a supportive, inspiring environment where genuine connections thrive.

What’s your philosophy on training and coaching, and how do you stay up-to-date with the latest research and trends?

Our philosophy is holistic and sustainable. We believe in balancing physical performance with mental well-being, proper recovery, and consistent effort. I personally stay informed by engaging with fitness professionals, and continuously integrating new methodologies. We also pay close attention to local and global wellness trends.

Original article appeared on GLAMOUR’s May issue 2025