The Wellness Brew - Issue 34

A subscriber asked me to write about exercising during pregnancy, and the research confirmed my initial thoughts. Quick note - if you have topic you’re interested in, please let me know! Exercise is great for you if you’re not pregnant and it’s great for you when you are pregnant. Most of the restrictions women get told about are not in the formal guidelines, and the guidelines themselves are considerably more permissive than their reputation.

But first, we filtered the noise — here's what's worth knowing this week.

Apolipoprotein B, usually shortened to ApoB, is a protein that rides on every cholesterol particle capable of lodging in an artery wall (not all cholesterol does this). Measuring ApoB counts the plaque-forming particles instead of just the cholesterol inside them. Allan Sniderman has spent a career arguing it is the number worth tracking, which is what makes his new paper worth a look. Among 293,872 UK Biobank participants free of heart disease and taking no cholesterol medication, high HDL, the “good” cholesterol, was tied to lower risk independent of ApoB, and it softened ApoB’s effect. The authors’ word is “attenuates.” Online summaries have upgraded that to “vanishes,” which the numbers don’t carry: the interaction came to a hazard ratio of 0.95, and ApoB still ran 1.16 per standard deviation. The authors state plainly that an observational study of this kind cannot establish cause. It’s a real signal in an area where the honest position is still that we know less than the confident opinions suggest. — Sniderman A et al., European Journal of Preventive Cardiology, 2026.

Rhonda Patrick brought up canned soup on the Rich Roll podcast, pointing to a 2011 trial worth knowing about. Harvard researchers had 75 people eat a 12-ounce serving of canned soup every day for five days and freshly prepared soup for five days, in random order, with a break in between. Urinary bisphenol A, or BPA, a chemical used to line cans, averaged 1.1 micrograms per liter after the fresh soup and 20.8 after the canned, which the authors reported as a 1,221% increase and among the highest readings ever recorded outside an industrial setting. Two things have changed since 2011. The trial used Progresso, and Progresso now states its cans are non-BPA lined, so the specific lining behind that spike has largely left American shelves. What replaced it is the harder question as many BPA replacements (BPF, BPS) are often just as harmful. When the Ecology Center took apart 192 cans, it found five different coating types and almost no published safety data on any of them. Make your soup fresh at home. — Carwile JL et al., JAMA, 2011. Can linings: Ecology Center, 2016. Progresso’s statement: progresso.com.

Testing commissioned by Greenpeace has been drawing attention for estimating more than 11,000 microplastic particles in a single Happy Baby Organics pouch and more than 5,000 in a Gerber pouch. Greenpeace campaigns against plastic packaging and its public report names neither the lab nor the counting method, so give the specific numbers some slack. Consumer Reports ran the better-built version of the same question, testing 16 baby foods sold in pouches, plastic tubs, and glass jars. It found microplastics in all 15 purées it could analyze, at counts far higher than Greenpeace reported, including 814,589 particles in one plastic tub and 330,079 in a glass jar. Different labs and detection floors mean the two sets can’t be lined up against each other, and no agency has set a level at which these counts violate any laws. What is clear is that microplastic exposure continues to grow and switching containers won’t fix it, since the glass products were contaminated too. Consumer Reports points to factory equipment and worker clothing as likely sources. Blending whole food at home is your safest option. — Greenpeace, 2026. Comparison testing: Consumer Reports, 2026.

Start with the formal position, because it's considerably more permissive than almost anyone expects.

The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women get at least 150 minutes of moderate aerobic activity a week, spread across the week, in sessions of 30 to 60 minutes, three or four times a week or more. [1] Canada's national guideline sets the same 150-minute target and adds that the week should include both aerobic work and resistance training, with pelvic floor exercises done daily. [2]

Moderate doesn't mean easy here. Both documents put it at roughly 13 to 14 on a twenty-point exertion scale, a level described as "somewhat hard." The simpler version is the talk test: if you can still hold a conversation, but it’s somewhat difficult, you’re at moderate. .

Women who were sedentary before pregnancy are told to build up gradually. Women who were already training are told they can continue at higher intensity, running included, provided the pregnancy is uncomplicated. Neither guideline tells a fit woman to back off.

On the oldest piece of pregnancy advice there is, ACOG is blunt. There's no credible evidence that bed rest prevents preterm labor or preeclampsia, routine restriction isn't recommended, and it carries real risks of its own, including blood clots. [1]

The case for training through a pregnancy isn't that it's allowed. It's that it can change outcomes for the better.

Blood pressure disorders. A 2018 meta-analysis pooled 22 randomized trials of exercise-only programs and found gestational hypertension roughly 39% less likely among the women who exercised, with an odds ratio of 0.61. Across 15 trials, preeclampsia came out about 41% less likely, odds ratio 0.59. [3]

Those are the two worth committing to memory. Preeclampsia is among the leading causes of maternal death worldwide, and the list of things that lower the risk is short. Low-dose aspirin after 12 weeks is recommended for women already identified as high risk. Calcium helps women whose intake is low. Exercise is the one on that list available to everyone, and it doesn’t require being flagged for anything first. 

Gestational diabetes. A 2024 review that pooled 18 separate meta-analyses found 16 of them reported a preventive effect, with risk reductions clustering between 24% and 38%. [4] Two caveats the reviewers raise and I'd keep. The effect is less consistent in women who are already overweight or obese, which is frustrating given that group starts at higher risk. And the benefit looks larger when activity begins early in pregnancy and continues, rather than being picked up partway through.

The rest of the list. Both national guidelines also attach exercise to lower rates of cesarean delivery, instrumental delivery, excessive weight gain during pregnancy, urinary incontinence, and depression both during and after pregnancy. [1][2]

150 minutes a week is working on blood pressure, blood sugar, delivery, continence, weight and mood simultaneously. It costs nothing, the side effects are better sleep and more energy, and the dose is adjustable. More than any drug can claim.

Many women have heard that 140 beats per minute is the maximum heart rate they should reach while exercising during pregnancy. It appears in the ACOG guidelines, in a table, as an upper bound. However, the text of that same guideline says heart rate is a poor way to gauge intensity in pregnancy, since the response varies between women and is blunted in some, and recommends perceived exertion instead. [1]

ACOG also states that women who were already training can continue at higher intensity, running included, provided the pregnancy is uncomplicated. And in 2023, researchers ran pregnant women through ten one-minute cycling intervals above 90 percent of maximum heart rate, each followed by a minute of recovery, and compared that against 30 minutes of steady moderate work. Both were well tolerated. [9]

Lifting is the second example, and it shows how the caution got built in the first place. Guidelines have long discouraged heavy resistance work and training while on your back, and until last year nobody had actually measured whether the worry held up. 

In 2025 two independent groups did. Researchers at the University of Alberta took ten pregnant women, all between 22 and 31 weeks and all with at least two years of lifting behind them, through back squats, supine bench press and deadlifts at 70, 80 and 90 percent of their ten-rep max. Then they had them repeat the heaviest set while holding a Valsalva brace through the entire rep, the breath-hold lifters use under load, which had been warned against with almost nothing behind it. Fetal heart rate and umbilical blood flow were measured by ultrasound during the rests between sets. Nothing moved. No significant change in fetal heart rate across any of the three lifts, no episodes of it running fast or slow, and umbilical blood flow inside normal range the whole way. [5] 

A Norwegian group ran a larger version with 48 pregnant athletes doing sumo deadlifts, bench press and incline press, three sets of eight, stopping one rep short of failure. Fetal heart rate stayed within the normal range across all three lifts. Umbilical artery flow didn’t change. One woman out of the 48 developed symptoms of vena cava compression after the supine work, which passed quickly without her fetal heart rate leaving the normal range. The authors concluded that trained women can do heavy resistance work, supine lifts included, without compromising fetal wellbeing. [6] 

All of the above assumes an uncomplicated pregnancy. Some conditions change the calculation, and these are worth knowing rather than guessing at. 

Talk to your doctor before exercising if any of these apply: ruptured membranes, premature labor, unexplained persistent vaginal bleeding, placenta previa after 28 weeks, preeclampsia, incompetent cervix, intrauterine growth restriction, triplets or more, or uncontrolled type 1 diabetes, hypertension or thyroid disease. A second group calls for a conversation rather than a stop: recurrent pregnancy loss, gestational hypertension, a history of spontaneous preterm birth, symptomatic anemia, an eating disorder, or twins after 28 weeks. [2]

Stop and call someone for vaginal bleeding, abdominal pain, regular painful contractions, fluid leaking, breathlessness before you've started exerting, dizziness, headache, chest pain, or calf pain or swelling. [1]

Three things to avoid regardless of how fit you are: scuba diving, contact sports or anything carrying a real risk of a fall or a blow to the abdomen, and prolonged heat, meaning hot tubs and saunas rather than a warm gym. [1]

The standard advice is a six-week checkup, after which you’re cleared. It manages to be wrong in both directions.

Too late for gentle movement. ACOG says to resume activity gradually as soon as it’s medically safe, which after an uncomplicated delivery can be within days, and that pelvic floor work can begin immediately. [1] The physiotherapists behind the leading return-to-running guidance say it more plainly: waiting for the six-week appointment before starting low-intensity activity is too long to wait. [7]

And too early to count as clearance for running. Six weeks is the point at which a pelvic health assessment should be offered, not the point at which impact gets approved.

For years the answer to that was a flat rule: no running before three months. In 2024 an international panel of 95 clinicians and exercise professionals, including two of the three authors of that rule, landed somewhere else. Their consensus is that the timeline should be fully individualized, that being postpartum doesn’t confine anyone to a twelve-week waiting period, and that the only floor worth stating is three weeks. [8]

What replaced the date is more useful than a date. It’s a screen, and you can run it yourself.

Walk 30 minutes. Balance on one leg for 10 seconds. Ten single-leg squats per side. A minute of jogging on the spot. Ten forward bounds. Ten hops on each leg. [7]

All of it without pain, without heaviness or dragging, and without leaking. That last one is what gets skipped. The signal isn’t how fit you feel, it’s whether the tissue is handling load, and those are different questions. A woman can feel entirely ready and fail on the tenth hop.

The 2024 panel added a second layer almost nobody gets asked about: sleep, hydration, fatigue, whether you’re eating enough for what you’re doing, and mental health. Energy availability matters here in particular, and it’s the same problem that turns up in female athletes who aren’t pregnant at all.

Two honest limits. This is expert consensus rather than trial data. And while the panel agreed on which milestones matter, they couldn’t agree on minimum benchmarks for most of them. It’s still a great deal more useful than a number on a calendar.

The guidelines are more permissive than their reputation, and most of the restrictions women actually hear aren't in them. Train at least 150 minutes per week, doing both aerobic and resistance exercise, and if you were already training, keep doing what you were doing.

The benefits aren't marginal. Lower odds of gestational hypertension, preeclampsia and gestational diabetes, plus better numbers on delivery, continence, weight and mood, out of something that costs nothing.

Afterward, don't wait for a six-week appointment to start walking, and don't treat that appointment as permission to run. Pass the screen first.

Four things you can do this week:

1. Hit 150 minutes a week, and don’t let it all be cardio. Both the American and Canadian guidelines call for aerobic work and resistance training, not one or the other, and the strength half is the part that routinely gets dropped. If you were already lifting before you got pregnant, two studies published last year measured fetal heart rate and umbilical blood flow during heavy barbell work, bench press included, and found it well tolerated. If you weren’t lifting, start light and build. Either way, don’t let walking become the whole plan.

2. Ignore the 140 beats rule. If there’s a real ceiling, it’s far higher. The number sits in a table in ACOG’s guideline whose own text says heart rate is a poor way to gauge intensity in pregnancy. Vigorous work isn’t off limits — the guideline says women who were already training can keep training hard, and a 2023 study ran pregnant women through ten one-minute intervals above 90% of max heart rate without trouble. Use the talk test to find easy and moderate work. Go beyond that if you’ve been training hard and be smart, listen to your body. 

3. Do pelvic floor work daily, starting now. Canada’s guideline lists it as a standing recommendation during pregnancy specifically to lower the risk of urinary incontinence, and ACOG says it can restart immediately after delivery, before anything else does. It takes a couple of minutes, nobody can tell you’re doing it, and it’s the item on this list most likely to be skipped because it doesn’t feel like exercise. It’s also a large part of what the postpartum return-to-running screen is measuring, so the work you do now is what you’ll be tested on later.

4. Afterward, walk early and run on a test rather than a date. Don’t wait for the six-week appointment to start gentle movement. The physiotherapists who wrote the return-to-running guidance say that’s too long to sit still. But don’t treat that appointment as clearance to run either. Before going back to impact: walk 30 minutes, balance on one leg for 10 seconds, 10 single-leg squats per side, a minute of jogging on the spot, 10 forward bounds, 10 hops on each leg. All of it with no pain, no heaviness or dragging, and no leaking. Failing part of it isn’t a verdict, it’s a list of what to work on.

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Wellness, filtered.

The Wellness Brew

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Disclaimer: The Wellness Brew is for informational purposes only and does not constitute medical advice. The content published here is not intended to diagnose, treat, cure, or prevent any disease or health condition. Always consult a qualified healthcare professional before making any changes to your diet, supplement routine, or lifestyle.