To HIIT or not to HIIT, Midlife Women's Health, and Moderate Alcohol on Stress

February Midlife Roundup [2025]

Photo by Kostiantyn Li on Unsplash

Did I tell you I got a Peloton for Christmas?

I know I’m late for this health trend like I always am. I’ve considered getting one for the past several months.

And I finally pulled the trigger.

The reason has to do with wanting to do more high-intensity interval training (HIIT). I started using a bike at the gym for this purpose for 20 minutes on days I did strength training.

And I really enjoyed it. Then one day I went to do interval training, and I found the bike broken. It never got fixed because in a couple of weeks it was gone.

Before that I was doing interval training by running up hills, but it felt like too much. Not the Peloton. I’ve been enjoying it for a few weeks; it’s so convenient having it at home.

But what does the research actually say about HIIT for women in midlife? There are so many mixed messages.

So, for this roundup I’ll touch on some of the research on upping the intensity for short bouts, along with two other studies that caught my eye.

High-intensity interval training

High-intensity interval training (HIIT) has been popular for nearly 20 years, although it’s been around much longer than that.

HIIT involves short bursts of intense exercise (around 80% or more of your maximum heart rate), followed by low-intensity exercise or rest periods.

One of the great things about HIIT is that you can do it anywhere without needing special equipment. It’s known for being a time-efficient way to improve VO2 max and enhance cardiorespiratory fitness. Additionally, HIIT helps burn fat—especially visceral fat—and increases the production of energy-producing mitochondria.

Honestly, I never fully embraced HIIT when it was all the rage (again, I naturally shy away from trends). That being said, I did start incorporating it into boot camp workouts and also began adding walk/run intervals to my running routine.

Then, like many women in midlife, I came across information that HIIT may not have the same benefits for women at this stage of life. From what I’ve read, it seems that HIIT might not burn as much fat in postmenopausal women.

In Stacy Simms’ book Next Level, I discovered an alternative: sprint interval training (SIT). Unlike traditional HIIT, which uses longer intervals (2-4 minutes), SIT involves much shorter, more intense bursts, typically lasting 20-30 seconds.

It’s also considered even more intense, with an “all-out” effort.

“Unless you’re following a specific training plan for competition, your intervals don’t need to be long. In fact, it’s better to keep them short,” writes Selene Yeager on the Feisty Menopause website. “When you start stretching your intervals past 60 seconds, you can get greater increases in the stress hormone cortisol.”

She says that cortisol is not necessarily bad, but that shorter bouts of intense activity may be better for midlife women.

The research is still in its infancy and the truth is women can get benefits of many types of interval high intensity (short and long).

In writing this, I found a study looking at endothelial health in midlife women, comparing moderate intensity to HIIT, on flow mediated dilation (FMD) or how well our blood vessels dilate.

Because as I describe more in this post, blood flow during exercise is important.

Comparing MICT to HIIT

Researchers randomized thirty postmenopausal women into either a low-intensity continuous training (40% HR) group or a sedentary group for 12 weeks.

The second intervention was an 8-week training group with 18 women placed into either moderate-intensity continuous training (MICT) group or HIIT for 8 weeks

MICT included treadmill running at 70-80% maximum HR. HIIT was four sessions of 4-minute-high intensity (85-95%) followed by 3-minute lower intensity (60-70%)

The researchers measured FMD, nitric oxide, and wall shear stress before, during, and after the interventions.

The great news is that all groups had increases in FMD, NO, and shear stress. Shear stress is the force of flowing blood against the vessel wall, which works to increase nitric oxide release.

When comparing MICT to HIIT, you can see an advantage to HIIT but not by much. HIIT was the only group to decrease endothelin, a vasoconstrictor. To give you an idea, premenopausal levels of FMD are typically around 10%.

I’ll be discussing different types of cardio in more detail later, but for now, it’s important to remember that any form of exercise is beneficial—whether it’s low-intensity, moderate, or high-intensity (with intervals). Hybrid training, which incorporates a variety of exercises, not only keeps things interesting but also offers additional benefits.

I’ve noticed a trend in smaller gyms offering mainly strength classes. When I asked about cardio options at my current gym, the trainer said, “People can do that on their own.”

I enjoy Peloton classes because they provide a clear measure of intensity and tell me exactly what to do. I’ve been doing Tabata-style workouts for my 20-minute sessions. These typically consist of 30 seconds of intense work followed by 10 seconds of rest, repeated for about 8 rounds, followed by a longer rest period before repeating the cycle.

There is no magic exercise formula for midlife women. It comes down to what you think you can do consistently.

READ: The Case for Cardio

Common health conditions for midlife women

A new study from the Rochester Epidemiology Project in Minnesota, including 1.4 million people from the Upper Midwest in the US.

Researchers analyzed data from 86,946 women between the ages of 40 and 59, identifying the eight most common conditions that increase by 45% or more. They include:

1. Dyslipidemia like high cholesterol

2. High blood pressure

3. Sleep disorders

4. Thyroid disorders

5. GI issues (especially acid reflux)

6. Osteoarthritis

7. Tendon and synovial disorders (joint and connective tissue issues)

8. Menopausal symptoms such as hot flashes

These conditions were more common among Black women and those from disadvantaged socioeconomic backgrounds.

“Most studies examine men and women together. However, we know that men and women age differently, so it’s important to do separate studies to understand these differences,” said study author Jennifer St. Sauver, Ph.D., in this May Clinic press release.

We know these conditions all too well, and I’d venture to guess that a disruption of the One Health Principle causes most of them.

“The findings also underscore the need for increased research to understand underlying biological changes in women at midlife and how these changes contribute to the development of many conditions throughout the aging process.”

-Mayo Clinic, Colette Gallagher

Alcohol and stress signaling post

I found a 2023 study about alcohol and stress signals in the brain.

It came just after I read an article from a menopause doctor saying there are no benefits from alcohol, even moderate intake.

While I’m not promoting alcohol use, some data shows that light to moderate drinking can have cardiovascular benefits. And I just want women to have the complete information.

The study included over 50,000 people from Mass General Brigham Biobank. The first part examined the relationship between light/moderate alcohol consumption and heart attacks and strokes.

After adjusting for lifestyle, genetics, and other factors, there was a significant reduction in risk factors for cardiovascular events amount those with light to moderate alcohol intake.

The researchers took a subset of 754 of the study participants who had undergone PET/CT brain imaging. Those who lightly or moderately drank had reductions in stress signaling in the amygdala compared to abstainers or seldom drinkers, with a greater effect in those with anxiety.

The amygdala is the part of the brain linked to the stress response. When the investigators examined the participants’ histories of cardiovascular events, they found that light to moderate drinkers had fewer heart attacks and strokes.”

“We found that the brain changes in light to moderate drinkers explained a significant portion of the protective cardiac effects,” said lead author and cardiologist, Ahmed Tawakol in this Harvard Gazette press release.

But WHY does alcohol reduces stress signals in the brain? I go back to my review on alcohol.

And that’s that low levels of alcohol increase nitric oxide, while high levels decrease it.

Although its complex, NO plays a key role in the nervous system, including fear extinction. It’s totally hypothetical but interesting none-the less.

Since light to moderate drinking may help with stress, it’s important to acknowledge that before we tell every woman to quit. We should also consider alternatives, like slow breathing.

Ha!

The Midlife Morning Show

I mentioned last week that Ann Marie McQueen (from HotlfashInc) are starting a weekly live Midlife Morning Show. We’ve run into some bumps getting started but will kick it off next week, so stay tuned.

In the meantime, check out Ann Marie’s take on the much-publicized Pvolve workout study (featuring Jennifer Aniston).

It’s stuff like this we’ll be talking about on the live show.

Let me know how you’re doing in the comments!