Fitness

Combining small changes in diet, exercise and sleep may extend life | CNN

Published

3 months ago

January 16, 2026

Combining small changes in diet, exercise and sleep may extend life | CNN

Small changes in diet, exercise and sleep may extend life by a year when put into practice together, while making larger changes could provide more than nine additional years of life, according to a new study.

Combining changes in diet, sleep and exercise also increased “health span,” or the number of years a person may live without major health complaints.

“These findings highlight the importance of considering lifestyle behaviors as a package rather than in isolation,” said lead study author Nick Koemel, a research fellow in physical activity, lifestyle and population health at the University of Syndey’s main campus in Camperdown, Australia.

“By targeting small improvements across multiple behaviors simultaneously, the required change for any single behavior is substantially reduced, which may help overcome common barriers to long-term behavior change,” Koemel said in an email.

READ MORE: Can’t sleep? Take steps to improve your sleep hygiene, which boosts health.

However, that finding is far from conclusive, said Kevin McConway, professor emeritus of applied statistics at the Open University in Milton Keynes, United Kingdom, who was not involved in the study.

“A snag is that the paper uses complicated statistical methods that are not always described clearly,” McConway said in an email. “It’s therefore difficult to tell to what extent the findings have emerged from the researchers’ choice of statistical analyses, rather than things that are clearer from the data.”

Using scientific modeling, Koemel and his team found combining as little as five additional minutes of sleep, two minutes of moderate to vigorous physical activity (such as brisk walking or taking the stairs), and an additional ½ cup of vegetables a day might lengthen life by a year.

However, this predicted outcome was only for people who had an extremely poor diet, slept less than six hours per night and only exercised about seven minutes a day. In addition, it wasn’t until the model’s lifestyle improvements greatly increased that the results became scientifically significant.

“All of the gains reported in this study are theoretical,” Koemel said. “We cannot claim a direct causal effect from the lifestyle patterns. These findings should therefore be interpreted as expected or projected benefits under assumed behavioral variations, rather than confirmed effects of an intervention.”

The greatest gain in longevity — 9.35 years — and health span — 9.46 years — came with the combination of an addition of 42 to 103 minutes of exercise and sleeping between seven and eight hours a day, while also eating an extremely healthy diet that included fish, whole grains, vegetables and fruits.

Adding exercise to the mix moved the longevity needle the most — a fact that did not surprise preventive cardiologist Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver.

“Exercise is the elixir of youth,” said Freeman, who was not involved in the study. “But let me be clear — this study should not be interpreted as exercising for exactly two minutes and stop, you’ve accomplished a goal.

“Rather, you should aim to get 20 to 30 minutes of brisk, breathless physical activity, combining strength and cardio in every day. That advice has not changed over decades of study.”

READ MORE: Want to start moving? Check out this guidance to ease into walking.

The study, published Wednesday in the journal eClinicalMedicine, looked at almost 60,000 participants from England, Scotland and Wales in the UK Biobank, a longitudinal health study, who were followed for an average of eight years. Everyone in the study provided information on their diet — including ultraprocessed foods, such as sugar-sweetened beverages. A subset of the group also wore wrist watches that provided more objective measurements of movement and sleep.

Researchers gathered this medical data and used it to form theoretical scenarios of improved longevity and health span, which was defined as the number of years free of cardiovascular disease, dementia, chronic obstructive pulmonary disease and type 2 diabetes.

Enjoying a longer life and a longer health span, or remaining free of disease, aren’t the same thing, Koemel said. “Combined improvements in sleep, physical activity, and diet were associated with longer lifespans, even if people still developed some chronic conditions later in life.”

READ MORE: Want to improve your diet? Instead of making drastic changes, you can ease into the Mediterranean diet.

After adjusting the findings for many variables — such as the amount of ultraprocessed foods, smoking, alcohol use, body mass index, insomnia, snoring and daytime sleepiness — the results differed depending on how much of each behavior change was accomplished.

In addition to the lowest and highest levels of the lifestyle changes discussed above, researchers also found lower levels of exercise — less than 23 minutes a day — sleeping seven to eight hours a night, and an excellent diet were associated with nearly four more years of life and three years of health, the study found.

Moderate levels of exercise (between 23 and 42 minutes a day), sleeping up to eight hours per night, and a high-quality diet were associated with a greater improvement of an additional seven years of life and just over six years of good health. So many calculations! What does it all mean?

“This is not about the absolute minutes you exercise or sleep or the number of pieces of broccoli you eat. It’s about making sure that all the things you do in your life are synonymous with health,” Freeman said.

“This is a great time of year to reflect on how you live and make big changes that will set you up for a life of wellness by modifying your life’s trajectory,” he said. “The overall signal in the noise is if you live well, your health span and then your lifespan will be longer.”

Fitness

Higher fitness levels linked to lower risk of depression, dementia – Harvard Health

Published

9 hours ago

April 21, 2026

Press Room

Higher fitness levels linked to lower risk of depression, dementia – Harvard Health

research review

People with high cardiorespiratory fitness were 36% less likely to experience depression and 39% less likely to develop dementia than those with low cardiorespiratory fitness. Even small improvements in fitness were linked to a lower risk. Experts believe that exercise’s ability to boost blood flow to the brain, reduce bodywide inflammation, and improve stress regulation may explain the connection.

Fitness

These 20-Minute Burpee Workouts Replaced His Entire Gym Routine – and Transformed His Physique

Published

21 hours ago

April 21, 2026

Press Room

These 20-Minute Burpee Workouts Replaced His Entire Gym Routine – and Transformed His Physique

While many swear by them, most people see burpees as a form of punishment – usually dished out drill sergeant-style by overzealous bootcamp PTs. Often the final blow in an already brutal workout, burpees are designed to test cardiovascular fitness, muscular endurance and mental grit. Love them or loathe them, they deliver every time.

For Max Edwards – aka Busy Dad Training on YouTube – they became a simple but highly effective way to stay fit and lean during lockdown. Once a committed powerlifter, spending upwards of 80 minutes a day in the gym, he was forced to overhaul his approach due to fatherhood, lockdown and a schedule that no longer allowed for long, structured lifting sessions.

‘Even though I was putting in hours and hours into the gym and even though my physique was pretty good, I wasn’t becoming truly excellent at any physical discipline,’ he explained in a YouTube video.

‘I loved the intentionality of training,’ says Edwards. ‘The fact that every session has a point, every rep in every set is helping you get towards a training goal, and I loved that there was a clear way of gauging progression – feeling like I was developing competence and moving towards mastery.’

Why He Walked Away From Powerlifting

Despite that structure, Edwards began to question whether powerlifting was sustainable long-term.

‘My sessions were very taxing on my central nervous system. I was exhausted between sessions. It felt as if I needed at least nine hours of sleep each night just to function.’

He also noted that his appetite was consistently high.

But the biggest drawback was time.

‘I could not justify taking 80 minutes a day away from my family for what felt like a self-centred pursuit,’ he says.

A Simpler Approach That Stuck

‘Over the course of that year I fixed my relationship with alcohol and I developed, for the first time in my adult life, a relationship with physical training,’ says Edwards.

With limited time and no access to equipment, he turned to burpees. Just two variations, four times a week, with each session lasting 20 minutes.

‘My approach in each workout was very simple. On a six-count training day I would do as many six-counts as I possibly could within 20 minutes. On a Navy Seal training day I would do as many Navy Seal burpees as I could within 20 minutes – then in the next workout I would simply try to beat the number I had managed previously.’

This style of training is known as AMRAP – as many reps (or rounds) as possible.

The Results

Edwards initially saw the routine as nothing more than a six-month stopgap to stay in shape. But that quickly changed.

‘I remember catching sight of myself in the mirror one morning and I was utterly baffled by the man I saw looking back at me.’

He found himself in the best shape of his life. His energy levels improved, his resting heart rate dropped and his physique changed in ways that powerlifting hadn’t quite delivered.

‘It has been five years since I have set foot in a gym,’ he says. ‘That six-month training practice has become the defining training practice of my life – and for five years I have trained for no more than 80 minutes per week.’

The Burpee Workouts

1/ 6-Count Burpees

20-minute AMRAP, twice a week

How to do them:

Start standing, feet shoulder-width apart
Crouch down and place your hands on the floor (count 1)
Jump your feet back into a high plank (count 2)
Lower into the bottom of a push-up (count 3)
Push back up to plank (count 4)
Jump your feet forward to your hands (count 5)
Stand up straight (count 6)

20-minute AMRAP, twice a week

How to do them:

Start standing, feet shoulder-width apart
Crouch down and place your hands on the floor
Jump your feet back into a high plank
Perform a push-up (chest to floor)
At the top, bring your right knee to your right elbow, then return
Perform another push-up
Bring your left knee to your left elbow, then return
Perform a third push-up
Jump your feet forward
Stand or jump to finish

Kate is a fitness writer for Men’s Health UK where she contributes regular workouts, training tips and nutrition guides. She has a post graduate diploma in Sports Performance Nutrition and before joining Men’s Health she was a nutritionist, fitness writer and personal trainer with over 5k hours coaching on the gym floor. Kate has a keen interest in volunteering for animal shelters and when she isn’t lifting weights in her garden, she can be found walking her rescue dog.

Fitness

Six ways your smartwatch is lying to you, according to science

Published

1 day ago

April 20, 2026

Press Room

Six ways your smartwatch is lying to you, according to science

You check your smartwatch after a run. Your fitness score has dropped. You’ve burnt hardly any calories. Your recovery score is really low. It’s telling you to take the next 72 hours off exercise.

The worst bit? The whole run felt amazing.

So why is your watch telling you the opposite?

Ultimately, it’s because smartwatches and other fitness trackers aren’t always accurate.

Smartwatches can shape how you exercise

Using wearable fitness technology, such as smartwatches, has been one of the top fitness trends for close to a decade. Millions of people around the world use them daily.

These devices shape how people think about health and exercise. For example, they provide data about how many calories you’ve burnt, how fit you are, how recovered you are after exercise, and whether you’re ready to exercise again.

But your smartwatch doesn’t measure most of these metrics directly. Instead, many common metrics are estimates. In other words, they’re not as accurate as you might think.

1. Calories burned

Calorie tracking is one of the most popular features on smartwatches. However, the accuracy leaves a lot to be desired.

Wearable devices can under- or overestimate energy expenditure (often expressed as calories burned) by more than 20 per cent. These errors also vary between activities. For example, strength training, cycling and high-intensity interval training can lead to even larger errors.

This matters because people often use these numbers to guide how much they eat.

For example, if your watch overestimates calories burned, you might think you need to eat more food than you really need, which could result in weight gain. Conversely, if your watch underestimates calories burned, it could lead you to under-eat, negatively impacting your exercise performance.

2. Step counts

Step counts are a great way to measure general physical activity, but wearables don’t capture them perfectly.

Smartwatches can under-count steps by about 10 per cent under normal exercise conditions. Activities such as pushing a pram, carrying weights, or walking with limited arm swing likely make step counts less accurate, as smartwatches rely on arm movement to register steps.

For most people, this isn’t a major problem, and step counts are still useful for tracking general activity levels. But view them as a guide, rather than a precise measure.

3. Heart rate

Smartwatches estimate your heart rate using sensors that measure changes in blood flow through the veins in your wrist.

This method is accurate at rest or low intensities, but gets less accurate as you increase exercise intensity.

Arm movement, sweat, skin tone and how tightly you wear the watch can also impact the heart rate measure it spits out. This means the accuracy can vary between people.

This can be problematic for people who use heart rate zones to guide their training, as small errors can lead to training at the wrong intensity.

4. Sleep tracking

Almost every smartwatch on the market gives you a “sleep score” and breaks your night into stages of light, deep and REM sleep.

The gold standard for measuring sleep is polysomnography. This is a lab-based test that records brain activity. But smartwatches estimate sleep using movement and heart rate.

This means they can detect when you’re asleep or awake reasonably well. But they are much less accurate at identifying sleep stages.

So even if your watch says you had “poor deep sleep”, this may not be the case.

5. Recovery scores

Most smartwatches track heart rate variability and use this, with your sleep score, to create a “readiness” or “recovery” score.

Heart rate variability reflects how your body responds to stress. In the lab it is measured using an electrocardiogram. But smartwatches estimate it using wrist-based sensors, which are much more prone to measurement errors.

This means most recovery metrics are based on two inaccurate measures (heart rate variability and sleep quality). This results in a metric that may not meaningfully reflect your recovery.

As a result, if your watch says you’re not recovered, you might skip training — even if you feel good (and are actually good to go).

6. VO₂max

Most devices estimate your VO₂max — which indicates your maximal fitness. It’s the maximum amount of oxygen your body can use during exercise.

The best way to measure VO₂max involves wearing a mask to analyse the amount of oxygen you breathe in and out, to determine how much oxygen you’re using to create energy.

But your watch cannot measure oxygen use. It estimates it based on your heart rate and movement.

But smartwatches tend to overestimate VO₂max in less active people and underestimate VO₂max in fitter ones.

This means the number on your watch may not reflect your true fitness.

What should you do?

While the data from your smartwatch is prone to errors, that doesn’t mean it is completely worthless.

These devices still offer a way to help you track general trends over time, but you should not pay attention to daily fluctuations or specific numbers.

It’s also important you pay attention to how you feel, how you perform and how you recover. This is likely to give you even more insight than what your smartwatch says.

Hunter Bennett is a lecturer in exercise science at Adelaide University. This piece first appeared on The Conversation.