How Daylight Saving Time Affects Heart Health & Sleep?

What’s worse than a Monday morning? A Monday morning that involves you losing an hour of sleep! Every year, Daylight Saving Time (DST) leaves millions feeling groggy, sluggish, and reaching for extra caffeine. But beyond the temporary exhaustion, this seemingly small time shift poses real risks to heart health.

“The scientific evidence points to acute increases in adverse health consequences from changing the clocks, including in heart attack and stroke,” says Dr Adam Spira, PhD, MA, a professor in Mental Health.

Beyond cardiovascular concerns, DST can also impact mental health, metabolism, and cognitive function, contributing to depression, weight gain, and headaches. With the body’s internal clock struggling to adjust, it experiences fatigue and mood disturbances.

This blog explores the connection between DST, heart health, and sleep, along with the strategies to minimize risks and protect overall well-being.

What is Daylight Saving Time?

Daylight Saving Time (DST) is the practice of adjusting clocks forward by one hour in spring and back by one hour in autumn to make better use of natural daylight. This means we get longer daylight hours in the evening during summer but lose an hour of sleep when DST begins.

Now, when does DST happen?

• Spring Forward: Clocks are set one hour ahead, leading to lost sleep
• Fall Back: Clocks go one hour back, giving an extra hour of sleep

While “falling back” seems harmless, springing forward is where the real danger lies. Now that we understand DST’s purpose, let’s explore its unintended consequences, especially on our heart health.

The Problem with DST

While DST was meant to save energy, there are more downsides than benefits. The time change disrupts our body clocks, leading to increased heart attack risk, car crashes, workplace accidents, and sleep disorders. 

Sleep deprivation can have a drastic effect on heart health, and even an hour less sleep can create sleep deprivation cardiac effects. An Open Heart research conducted across hospital admissions in Michigan hospitals has shown a transient increase in the incidence of Acute Myocardial Infarction (AMI) after Daylight Saving Time in the spring. 

Some regions, like Hawaii and Arizona, have abolished DST, and many countries are debating whether to end the practice altogether. 

How Daylight Savings Affects Heart Health and Sleep?

Every spring, millions of people groan as they set their clocks forward for daylight savings time (DST), losing an hour of precious sleep. While it might seem like a minor inconvenience, this small shift in time has serious consequences for heart health. But why does losing just one hour of sleep wreak such havoc on our hearts? Let’s break it down.

Circadian Rhythm Disruption

Our bodies operate on a 24-hour internal clock. This is known as the circadian rhythm. This system regulates sleep, digestion, metabolism, and even cardiovascular function. The circadian rhythm is set by the timing and amount of bright light exposure our bodies get during the day. 

During the DST period, between March to November, our bodies are less exposed to morning light and more to evening light. This leads to circadian rhythm disruption. With the internal clock being out of sync with the sunlight’s clock, we start to feel tired in the morning and awake in the evening. 

This puts sleep health at stake, along with metabolism and heart health. Besides, our bodies don’t adjust immediately to this change. Instead, they experience stress and confusion, which can impact heart function like.

• Increased heart rate and blood pressure as the body struggles to adapt.
• Higher levels of cortisol (the stress hormone) put additional strain on the heart.
• Reduced melatonin production, which plays a role in cardiovascular regulation.

Simply put, your body gets hit with jet lag—but instead of a vacation, it’s a ticket to heart strain.

Sleep Loss Triggers Heart Stress

The body repairs and recovers when we sleep, including the cardiovascular system. Sleep deprivation is bad for both cognitive and physical health. It activates the body’s stress response, increasing cortisol and adrenaline levels. These are responsible for increasing heart rate and blood pressure. 

Poor sleep also reduces heart rate variability (HRV), a key marker of heart health, making the heart more vulnerable to stress. Chronic sleep disruption leads to inflammation and higher risks of hypertension and arrhythmias. To minimize heart stress, it is essential to get 7-9 hours of sleep every night. 

Blood Pressure Fluctuations

Daylight saving time (DST) can lead to noticeable changes in blood pressure levels. The abrupt shift in the sleep-wake cycle disrupts the body’s internal clock, leading to increased levels of stress hormones like cortisol. This spike in stress, combined with reduced sleep, can cause temporary elevations in blood pressure. Studies have shown that even minor changes in sleep schedules can impact cardiovascular health, making people with hypertension or heart disease more vulnerable. Over time, frequent disruptions in sleep due to DST may contribute to long-term blood pressure instability, raising the risk of heart-related complications.

Impact on Mental Health and Stress Hormones

The transition into and out of daylight saving time can significantly affect mental health. The sudden shift in daylight exposure can alter serotonin and melatonin levels, hormones that regulate mood and sleep. Many people experience increased anxiety, irritability, and even depressive symptoms during this period. The additional stress from sleep deprivation can also elevate cortisol levels, which, when consistently high, may lead to chronic stress 

Metabolic Disruptions and Weight Gain

Sleep plays a crucial role in regulating metabolism, and DST can interfere with the body’s ability to process food efficiently. A study from NCBI suggests that even a slight reduction in sleep duration can lead to increased hunger, cravings for high-calorie foods, and decreased insulin sensitivity. When the body doesn’t get enough rest, it produces more ghrelin (the hunger hormone) and less leptin (the hormone that signals fullness). This leads to overeating and weight gain. Additionally, fatigue caused by sleep loss can reduce physical activity levels, further contributing to metabolic imbalances and an increased risk of obesity and diabetes.

Effects on Work Performance and Cognitive Function

Did you know that losing just one hour of sleep can lead to a 5%–20% increase in workplace injuries, a 6% rise in car accidents, and reduced reaction times comparable to mild intoxication? One of the most immediate effects of daylight saving time is decreased cognitive function and work performance. Sleep deprivation impairs concentration, memory, and decision-making skills, making individuals more prone to mistakes. 

Difficulty in Adjusting Sleep Patterns in Different Age Groups

Not everyone adapts to DST equally, and age plays a key role. Young children and older adults struggle the most, as their sleep patterns are more sensitive to change. Babies and toddlers may become cranky and have trouble falling asleep, while older adults, especially those with sleep disorders, may face nighttime wakefulness and daytime drowsiness. Teenagers, already prone to late sleep cycles, may find waking up for school even harder, impacting their mood and academic performance.

Ideal Sleep Duration & Resting Heart Rate by Age

Maintaining adequate sleep is crucial for overall health, especially heart function. Below is the recommended sleep duration and normal resting heart rate (RHR) across different age groups.

Age Group	Recommended Sleep Time	Normal Resting Heart Rate (bpm)
Infants (4-12 months)	12-16 hours	100-160 bpm
Toddlers (1-2 years)	11-14 hours	98-140 bpm
School-age Children (6-12 years)	9-12 hours	75-118 bpm
Teens (13-18 years)	8-10 hours	60-100 bpm
Adults (18-60 years)	7+ hours	60-100 bpm
Older Adults (60+ years)	7-9 hours	60-100 bpm

How to Protect Your Heart & Sleep Through Time Changes?

Interestingly, when we gain an hour of sleep in the fall, the opposite happens: heart attack rates decrease by 21%. This simple observation reinforces the importance of consistent, high-quality sleep for heart health. More sleep is equal to a stronger, healthier heart. You can reduce the risks associated with losing an hour of sleep and support heart attack prevention with the following strategies:

1. Start Adjusting Your Sleep Schedule Early

One of the best ways to prepare for DST is to start shifting your bedtime a few days in advance. Instead of abruptly losing an hour overnight, try going to bed one hour earlier than normal each night in the days leading up to the time change. This gradual transition allows your body to adapt more smoothly, reducing the shock to your rhythm and preventing circadian rhythm disruption.

2. Stick to a Consistent Sleep Routine

Maintaining a regular sleep schedule, even on weekends, helps regulate your internal clock. Try to go to bed and wake up at the same time every day, even after DST begins. Avoid the temptation to “catch up” on lost sleep by sleeping in late, as this can further disrupt your body’s natural rhythms.

3. Reduce Screen Time Before Bed

Exposure to blue light from screens, such as phones, tablets, and computers, can interfere with melatonin production, making it harder to fall asleep. In the days leading up to DST, try to limit screen time to at least an hour before bed. Instead, unwind with a book, meditation, or light stretching to signal to your body that it’s time to sleep.

4. Get Morning Sunlight

Natural sunlight plays a crucial role in preventing circadian rhythm disruption. After the time changes, make an effort to get outside in the morning as soon as possible. Sunlight exposure helps reset your internal clock, making it easier to adjust to the new schedule. If natural light isn’t an option, consider using a light therapy lamp to help regulate your body’s sleep-wake cycle.

5. Watch Your Caffeine and Alcohol Intake

Caffeine and alcohol can both interfere with sleep quality, especially if consumed in the late afternoon or evening. In the days surrounding DST, be mindful of how much caffeine you’re drinking and avoid alcohol close to bedtime. Opt for herbal teas or warm milk instead to promote relaxation.

6. Prioritize Heart-Healthy Habits

As DST can increase the risk of heart-related issues, it’s especially important to focus on heart-healthy habits during this period. Here are some things that you can do: 

• Stay hydrated and eat a balanced diet rich in whole grains, fruits, and vegetables.
• Engage in regular physical activity, but avoid intense exercise right before bedtime.
• Manage stress through deep breathing exercises, yoga, or mindfulness techniques.

7. Take Short Naps Wisely

If you find yourself struggling with fatigue after the time change, a short power nap (10–20 minutes) can help recharge your energy levels. However, avoid napping too close to bedtime, as this can make it harder to fall asleep at night.

8. Listen to Your Body

Everyone responds differently to time changes, so pay attention to how your body feels. If you’re experiencing extreme fatigue, mood swings, or other unusual symptoms, it may be a sign that you need more rest or adjustments to your routine.

Don’t Let an Hour Cost You Your Health!

Losing just one hour of sleep might not seem like a big deal until you realize it could literally break your heart. Sure, DST was meant to save energy, but is it worth the cost to our health? As more studies reveal daylight saving heart risks, some places are ditching the time change altogether. But until the world catches up, the best way to protect yourself is to take control of your sleep.

Think of sleep as your heart’s personal bodyguard, regulating blood pressure, lowering stress hormones, and helping with recovery. But when sleep is compromised, the heart takes a hit, increasing the risk of cardiovascular disease and even sudden cardiac arrest.

Thus, being prepared can make all the difference. A CPR/AED course provides lifesaving skills to act quickly in a crisis and improve survival rates. So, don’t let lost sleep turn into lost chances. Protect your heart and be ready to save a life.