The Rundown

Exercise Clock. A new study out of the University of Manchester has examined internal body clocks to see how exercising at the same time of day might protect against bone and joint deterioration and injury. We all know that consistency is the key to reaching exercise goals. The results of this study suggest that sticking to a daily routine of when you work out is just as important, at least when it comes to bone and joint health.

Circadian rhythm is the daily 24-hour cycle that our bodies follow. The processes inside us that keep the rhythm going are often referred to as “clocks” and they are all connected to a central clock in our brain. Studies have shown that if these clocks are not in tune with our central timekeeper, we have a higher risk of certain health conditions, including cardiovascular disease. But until now, it wasn’t clear that the brain’s circadian timekeeping was able to sync with our intervertebral disk and cartilage clocks.

In a mouse model, researchers made the animals exercise on a treadmill during a time they would usually rest in order to demonstrate how unpredictable activity speeds up bone and cartilage deterioration.

Study author Qing-Jun Meng explains the outcome of the study, “Our results showed that physical activities in the morning, associated with daily patterns of sleep/wake cycle, convey timing information from the light-sensitive central clock in the brain to the weight-bearing skeletal tissues. In effect it’s telling your skeletal system it’s time to wake up.”

When this alignment is uncoupled with the brain, Meng adds, it can lead to adverse health impacts. “If you are constantly changing the time you exercise, you may be more prone to this desynchronization.”

It doesn’t matter if you mix up your exercise, as long as you establish some type of pattern. “Your body clocks will eventually realign with each other and you will adapt to it,” notes Meng.

The team believes that their findings could lead to more targeted treatments for musculoskeletal conditions like arthritis and help international athletes who cross time zones to better protect against injuries.

The Body’s Response to Vigorous Exercise. In a paper published last month in Military Medical Research, scientists from the Department of Energy’s Pacific Northwest National Laboratory (PNNL) analyzed more than 4,700 molecules from 11 young firefighters who completed a rigorous training exercise. The intention was to increase safety for first responders, members of the military and athletes.

Specifically, the PNNL researchers took an in-depth look at what happens in the body during strenuous exercise to see if they could detect danger from exhaustion in its earliest stages. As expected, they found hundreds of molecular changes in the firefighters. The differences before and after exercise showed the body’s efforts at repairing tissue damage, maintaining fluid balance, keeping up with increased demand on energy and oxygen, and regenerating proteins.

But saliva samples showed something unexpected. The oral microbiome, or the microbial mix of the mouth, revealed a decrease in signaling molecules important for inflammation and for fighting off viral infections.

This decrease in inflammation makes sense for people who are vigorously exercising because less inflammation allows them to more quickly breathe in air and fewer inflammatory signals in the respiratory system help the body improve respiration and blood flow.

But that’s also a problem, as corresponding author Ernesto Nakayasu notes, “People who are very fit might be more prone to viral respiratory infection immediately after vigorous exercise. Having less inflammatory activity to fight off an infection could be one cause.”

The team hopes that their findings will help explain why some people are more vulnerable to respiratory infection after a hard workout.

Extra Point

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Brawn: The Impossible Formula 1 Story. In this four-part docuseries, Keanu Reeves tells the underdog story of Brawn GP. In 2009, Ross Brawn took an understaffed, under-financed and independent team competing in the most expensive and technologically advanced racing series and did the impossible by winning the F1 World Championship. Brawn is streaming on Hulu.

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Thrive Forever Fit with Jay Nixon. This podcast’s mission is to “disrupt, inspire and transform the way you think, speak and act in the areas of nutrition, fitness, and mindset.” Jay focuses on how positive psychology can help you reach your goals.

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A Hiker and a Terrier Climbed a Peak. The Dog Came Home 72 Days Later. This piece from Outside magazine is a little less fitness and a little more canine miracle but I can’t resist a dog story. In this one, a very good boy called Finney miraculously lasted ten weeks on his own in the Colorado backcountry.