Weekly Newsletter

Are you getting the most out of your workout?

Optimize your workout with the latest on exercise plus makeup, timing, cannabis and more. Plus, learn how to save on F45 Training costs while you strengthen and heal.
A colorful photo shows a young white mother doing yoga on a mat in her airy, bohemian living room while her young child jumps around on a leather couch.

Hippocrates said, “If you are in a bad mood go for a walk. If you are still in a bad mood go for another walk.”

This week, we share fitness findings to inspire such movement moments—from the benefit of weekend-only workouts to skincare effects to timing your routine for peak sleep. We close with news about rising tuberculosis cases + bird flu in dairy cows.

But first, stretch and relax your fingers as you scroll down into…

  • The Checkup: witnessing + uplifting
  • Sweet Sweat: makeup + F45 Training + body clocks
  • Healthcare: TB + weekends + cow bird flu

The Checkup

Working out? Skip the makeup!

A Black man wearing a pale pink suit and helmet rides an electric scooter down a London sidewalk.

If exercise increases blood flow to our largest organ (our skin), does wearing makeup slow the flow?

To find out, researchers put makeup on half of study participants’ faces + had them run on treadmills. The made-up skin retained more moisture—a bad thing, since sweating helps regulate temperature. Made-up pores were smaller, and so couldn't flush oil and debris. And the made-up skin had higher levels of sebum—a marker of dirt, debris + bacteria that can contribute to acne.

For details, head to Time. And if you need pro help with conditions like rosacea, eczema or psoriasis, check out our $15 dermatology care.

Exercising to heal? Meet F45 Training!

A banner ad for Dr. B and F45 Training partnership to help qualifying members get a Letter of Medical Necessity online and save on F45 Training fees by using their HSA or FSA funds

When you have an illness or injury, a fitness class is probably not the first place to head for healing help. But with F45 Training, it could be.

F45 Training's group functional fitness classes offer an endless variety of challenging exercises + genuine team energy. Throughout every class, one or several coaches—all certified personal trainers—make sure that newbies + athletes alike work toward their individual goals.

“F45 Training coaches are super-involved, asking questions before the workout starts and prescribing alternative modifications, timings, reps and rest,” says longtime member Dan Raposo.

A marathon participant whose health + weight fluctuate, Raposo has stayed with F45 Training throughout varying abilities and injuries. “I have to imagine that if someone were to come in with, say, asthma, the coaches would be able to provide alternatives and be on top of their care throughout the workout because that has been my experience throughout my entire F45 Training fitness journey,” he says.

Dr. B is proud to officially partner with F45 Training to help make quality fitness more affordable.

For details about why we’re so pumped about F45 Training + to find out if you can save up to 40% off your F45 Training fees, read all about F45 Training + Dr. B.

Workouts + circadian rhythms

A color photo of a mountainous landscape where a man and woman in their fifties wearing hiking clothes scale a large rock on a cloudy spring day.

Science can’t tell us the best time to exercise. But our organs + tissues do follow various timekeepers. If we can understand their patterns, we can adjust our workout schedules to benefit our sleep + encourage peak performance.

Head to NPR for details. But here’s the gist:

Exercise aligns: Light is our primary time cue. But exercise also signals our peripheral clock, helping our systems sync + align. Trials show most of us will fall asleep earlier if we exercise in the morning + early afternoon.

Muscles have a clock: Muscles' mitochondrial efficiency peaks in the late afternoon. This may be why humans (young men in particular) can lift more weight + run the fastest during that time.

We can change that clock: Studies on mice suggest that if we work out at a new time, our muscles will eventually change + perform just as well then. Pro athletes have shown this to be true outside of studies, too.

Timing could become key: Eventually, exercise timing windows could help patients lower specific risk of cancer, diabetes, cardiovascular disease and more. For now, the best time to exercise is any time you do it!

Healthcare 411

US TB cases reach highest level in a decade (US News).  In 2023, 40 states reported increased tuberculosis cases across all age groups. Many were caused by latent TB, which happens when bacteria hibernate in the lungs + activate when the immune system is weak. The spread of Covid-19 may have been a factor in this, but it cannot be wholly assumed.

Weekend-only exercise could be just as beneficial as regular workouts, study shows (Women’s Health). People who pack their workouts into weekends can reap the same benefits as those who spread them throughout the week. Young women show the most benefits. The caveat? The weekenders worked at higher intensity for longer periods.

Experts confirm first bird flu outbreak in cows: Is it safe to drink milk? (Science Alert). 10% of herds in four dairy farms have contracted bird flu. No contaminated milk has come into the market, no milk shortages are expected + the cows will make a full recovery. But experts will watch this event to monitor how bird flu spreads on farms with multiple species.

Sign up for the free Dr. B newsletter for a weekly report on the latest in healthcare + research-based advice for staying healthy and mentally well.

Related articles