There is a BEST time to exercise for health and performance!

Dr. Michael Breus
Nov 14, 2016 · 8 min read

Get faster, fitter and leaner — all on bio time

In my new book, The Power of When, I show how your body’s internal biological clock can point you toward the best times to do just about everything that life asks and offers, from eating and sleeping to working and playing, from exercise and disease-prevention to sex and relationships.

Have you ever noticed that there are certain times when you prefer to do certain things — and that those preferences don’t necessarily align with others’ around you? You like to sleep as late as you can, while your partner is up before dawn. You’re diligent about making time to work out, while your co-worker goes to the gym once in a blue moon. You’d rather jump into your exercise routine with the sunrise, while your roommate likes to workout after dinner. You’re full of energy in the morning, while your best friend hits her stride after work.

These preferences are expressions of your body’s powerful biological rhythms, which regulate an incredible range of activity and behavior. These preferences are generally grouped into three categories, which are known as chronotypes. They are the early birds, who prefer mornings, the hummingbirds, who have an in-between preference, and the night owls, who prefer evenings.

Long-held conventional wisdom says that there are these three chronotypes, and that’s it. My clinical experience has led me to a different conclusion. I have come to recognize a fourth chronotype, one that’s typically overlooked and often misunderstood: the restless sleeper, or the insomniac.

I have created four archetypes (using fellow mammals, not birds), to represent these four distinct chronotypes:

Lions are morning types.

Bears are middle of the road types.

Wolves are nighttime types.

Dolphins are difficult sleepers.

To unlock the power of when and use your body’s bio time to guide you to the best times for everything you do, you first must know your chronotype. To discover your individual chronotype, visit:

Take the chronotype quiz, and come back to learn about how your chronotype influences your athletic abilities and your preferences for exercise.

Ready? Here we go.

Want to run faster and enjoy it more?

For every dogged runner out there, there are also plenty of want-to-be runners who have a tough time getting into the running groove. Syncing your running routine to your bio time can help hope-to-be runners finally stick with a running routine — and enjoy it. If you’re already logging miles, using bio time can help you get more out of your runs, whether you’re looking to improve your health, boost your performance — or both.

The fat-burning rhythm

The best time to run depends on what you’re most looking to get from the activity. There are rhythms that can help you boost your speed and performance and to improve your health in other ways. But if you’re running first and foremost to lose weight, you’ll want to pay particular attention to the fat-burning rhythm. Peak times for this rhythm occur in the morning and the evening.

The morning run: A run before breakfast, within 30 minutes of waking will rev up your metabolism and convert fat into energy. At this point in the day, you’re still in fasting mode from the night’s sleep — and you haven’t consumed any carbohydrates for your body to burn. Be sure to hydrate well before you begin your morning run. Follow this run with a breakfast that is 50 percent protein, 50 percent carbohydrate, to keep your metabolism firing.

The evening run: Running at the end of the day delivers a surge of endorphins throughout the body that suppress appetite, right as you enter the time when many people are prone to overeating.

Either the morning run or the evening run can help you lose weight and practice weight control effectively. There is evidence that the morning run is more likely to be ingrained as a habit than the evening run. Your chronotype will also help determine which run makes more sense for you.

The performance rhythm

The science is pretty staggering. Research indicates that individual athletic performance can vary by as much as 26 percent depending on the time of day, morning or evening. A recent study demonstrated that the single most significant factor in predicting peak athletic performance is the time of performance relative to the time an athlete prefers to wake.

· Morning types perform best in the late morning.

· In-between types perform best in the afternoon.

· Evening types perform best in the evening.

To make the most of the performance rhythm, schedule your run in alignment with your preferred wake up time.

The rest rhythm

Exercise in the morning can help you sleep more soundly at night — which in turn can improve your health, lowering blood pressure, easing stress and anxiety, improving cardiovascular health, and boosting immune function. A study looked at the impact of exercise at different times of day on nightly sleep. Researchers found the morning exercisers saw the most significant benefits to blood pressure and to sleep. People who walked a treadmill at 7 a.m. saw a 10 percent post-workout drop in blood pressure, followed by an even greater blood-pressure drop that evening. The morning exercisers also saw a 75 percent increase in their deep sleep.

People with sleep troubles — Dolphins, I’m looking at you — may find the most advantage from the rest rhythm, and morning runs.

For all chronotypes, the worst time to run is the very early morning — 6 a.m. (Lions may not like reading this, but listen anyway.) At this hour, core body temperature is still low, and muscles and joints are especially vulnerable to injury. Your risk for injury will drop significantly if you wait 90 minutes before lacing up for your run.

The best time to run

Lions: 5:30 p.m. Lions will receive a welcome energy boost from this late-afternoon run.

Dolphins: 7:30 a.m. Morning runs will help these light sleepers sleep longer and more deeply.

Bears: 7:30 a.m. or noon. The early-morning run takes advantage of the fat-burn that comes from working out before breakfast and the midday run will keep appetite in check for the afternoon.

Wolves: 6 p.m. Wolves can take advantage of the evening fat burn and appetite suppressant (they tend to be hungriest at night), and enjoy their peak performance at this time.

The Best time to do YOGA

Find your best downward dog using bio time

Yoga delivers a potent range of mental and physical benefits that make it a nearly ideal exercise. Practiced regularly, yoga increases flexibility, expands lung capacity, reduces stress, builds physical strength and enhances mental clarity and focus. You can get even more of these benefits from yoga when you practice it in sync with bio time.

The flexibility rhythm

If you want to improve your range of motion and muscle tone, pay attention to this rhythm when you schedule your yoga session. Flexibility, and the body’s ability to move deeply into yoga poses, is greatest when body temperature is high. All those hot yoga places you see? They’re working on the same basic principle as the flexibility rhythm: a warm body is a flexible and supple one. When body temperature is low, you’re stiff, and more likely to injure yourself.

For all chronotypes, body temperature is high enough for yoga three hours after waking and again in early evening. Body temperature is low within 90 minutes of waking, and starting about three hours before bed.

The relaxation rhythm

If relaxation is you main goal, yoga is an excellent choice of exercise. Research shows this ancient practice lowers both blood pressure and cortisol levels. (Cortisol is sometimes referred to as the “stress hormone.”) I recommend practicing yoga to reduce stress as needed throughout the day, as well as using yogic deep breathing to alleviate anxiety whenever it arises.

Light yoga stretching is a relaxing, sleep-promoting pre-bed routine for all chronotypes. I encourage people to include low-intensity stretching as part of their Power Down Hour before bed. (For video instructions, visit

The mind-body connection rhythm

Yoga sharpens mental abilities, including alertness, concentration, and memory. It can also change thinking styles. Certain traits, patterns of thinking, and learning preferences are associated with yogis, according to research. A study looked at personality, morning-evening preferences, and thinking styles among yoga practitioners and found that yogis fall into the Bear chronotype more frequently than in the general population, and into the Wolf type less frequently than in the general population. Lions were found among yogis at the same rate they are found in the overall population.

Many personality traits corresponded to the personality traits we see in chronotypes — Lion yogis are conscientious, Wolf yogis are impulsive, the study found. Most yogis of all chronotypes were found to be open minded and inclined to creative, right-brain thinking. This suggests that yoga can have an impact on the thinking styles of all chronotypes.

Research also indicates that yoga can make even the nay-saying Wolf chronotype more optimistic. A study tracked mood changes among chronotypes after yoga. While all chronotypes experienced improvements to mood after a yoga session, evening types — Wolves — improved most dramatically. For Wolves, the mind-body connection rhythm of yoga can have a transformative effect on mood and outlook.

The best time to strike a warrior pose?

Dolphins: 10 p.m. Nighttime yoga will help lower cortisol and blood pressure

Lions: 8 a.m. or 5 p.m. Treat yourself to yoga before work — or right after.

Bears: Noon or 6 p.m. Before lunch and before dinner are ideal yoga times for this chronotype.

Wolves: 6 p.m. or 10 p.m. Yoga before dinner or to relax before bed.

The BEST time to Train for Strength

Get stronger — and leaner — thanks to bio time

Strength training builds muscle mass. This not only makes you stronger, it speeds up your metabolism, making it easier for your body to burn fat. Strength training is an important part of any fitness regimen — especially one that is geared to losing weight and improving metabolism.

The muscle growth rhythm

A study investigated the influence of time of day on muscle mass increase in men who strength trained daily. Researchers found both morning and afternoon strength training led to the same increase in muscle volume. Time of day isn’t a critical factor in muscle growth. Consistency and frequency of training are what deliver results.

The muscle strength rhythm

Paying attention to this rhythm enables you train when you’re at your strongest of the day. Research shows that the best time for resistance training is late afternoon. This is when core body temperature is high, for all chronotypes. It’s also when levels of the hormones testosterone and cortisol are low. The ratio of these two hormones — which both fluctuate throughout the day according to bio time — affects strength.

For Lions, late afternoon is when the cortisol-testosterone ratio is ideal to train for strength.

For Bears, this ratio hits its ideal strength training point in early evening.

Dolphins and Wolves, the cortisol-testosterone ratio reaches its ideal point for resistance training in late evening.

The best times to strength train:

Dolphins: 8 p.m.

Lions: 2:30–5 p.m.

Bears: 4–7 p.m.

Wolves: 6–7 p.m.

Whether you’re a tough-as-nails triathlete, a yoga and Pilates devotee, or the most enthusiastic outfielder on your company’s softball team, we all benefit from unleashing our inner athlete. You can use your body’s own bio time to get bigger rewards from your exercise — and make it feel more fun and rewarding while you’re doing it.

Unlock your Clock, Unlock your Potential

Sweet Dreams,

Dr. Breus

Michael J. Breus, PhD, is a board-certified sleep specialist. His book, The Power of When: Discover Your Chronotype — and The Best Time to Eat Lunch, Ask for a Raise, Have Sex, Write a Novel, Take Your Meds, and More, explores how to use your body’s bio time to improve your health, happiness, productivity, and relationships.

Dr. Michael Breus

Board Certified Sleep Specialist, author and expert. Providing information, guidance, & real solutions for a better night's #sleep!

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