Female-Specific Exercise & Nutrition for Health, Performance & Longevity | Dr. Stacy Sims

Women need heavy loads to trigger CNS adaptations that replace estrogen's role in strength

Low-rep heavy lifting activates the central nervous system in ways that high-rep training can't, and this becomes critical as women age and lose estrogen's support for strength.

"So the almond milk is sweetened and usually it's unsweetened, but sweetened for the carb and then the protein powder for the protein. Because if I'm going to go do an ocean swim, then I need some carbohydrate and protein on board. If I'm going to just go to the gym, then I'll probably just have the protein powder in the coffee. Yes, I'm caffeinating, but I'm also getting the calories for the hypothalamus and getting some more circulating amino acids. Abby Smith-Ryan out of UNC did some specific work looking at carbohydrate, protein, B4 and strength or cardio and found that if you're going to do a true strength training session, you only need around 15 grams of protein before you go to really help you get into the idea that, yes, you have some fuel on board and also increases your post exercise oxygen consumption or your EPOC. So your resting metabolism stays elevated, giving you a better chance for recovery post exercise as well. If you're going to do any kind of cardiovascular type work up to an hour, then you're adding 30 grams of carb to that. So it's not a lot of food and it's not a full meal. Other people are like, I'm starving right before I go training. Then yes, you can have your meal, giving yourself about a half an hour before. But it doesn't have to be major food that we're talking about. But that's just enough to bring blood sugar up and stimulate the hypothalamus to say, yeah, there's some nutrition coming in. And then you have your real food afterwards. You have your breakfast afterwards within 45 minutes."

Post-workout protein window: 35g within 45 min for premenopausal, 40-60g for peri/post

Women need protein sooner after training than men because their metabolism returns to baseline faster. Premenopausal women need 35g, while perimenopausal and older women need 40-60g due to anabolic resistance.

"Seems to me that's what most people are doing if they're investing in resistance training, maybe plus or minus, what, 20 minutes? And they're hitting those high-intensity sets where they have maybe just one or two repetitions in reserve, maybe going to failure on a few of those sets. What do you recommend women eat after they train? So we know that women who are in their reproductive years need around 35 grams of good protein, high quality leucine oriented protein within 45 minutes. And we see that women who are perimenopausal onwards are 40 to 60 grams because we become more anabolically resistant to food and exercise as we get older. When we look at like the recovery window for food, there are definitely sex differences because we hear all the conversation of there's no recovery window. It's, you know, it's old science. But we look at the research of when women's metabolisms come back down to baseline, meaning that they have constant straight blood sugar levels versus men."

Women gain strength fast from lifting because their CNS hasn't been trained yet

Women new to resistance training see rapid strength gains because the nervous system adapts quickly. Cultural norms pushed women toward cardio, so most have untapped neural strength potential.

"The whole aspect of getting the nerve and the acetylcholine, which are little vesicles that hold the ability for the nerve to actually stimulate the muscle fiber, all that gets trained really quickly."

How beginners can start lifting safely at home with bodyweight and a loaded backpack

Resistance training is the bedrock for body composition, metabolic control, and brain health. Beginners can start at home with bodyweight squats and lunges, a loaded backpack, and mobility work.

"Yeah, this is where I love technology, for one thing. But if we're staying really basic, I look at some of my family members and I've gotten them started with just body weight stuff or loading a backpack with cans to add a little bit of resistance. So they feel comfortable in their own house and they might be doing lunges or squats, um, just keying them up of like where foot placement and knee and that kind of stuff. So they're getting used to that kind of movement. Um, I love Kelly Starrett's stuff with mobility. So show them like, here's how we do some of the mobility to find where the sticking points are. And then you can either direct them to some of the programs that are out there that like Haley happens has some really good ones for women who are 40 plus. So does Bree and then Sunnyny Webster down in Australia."

The 10-minute rule: how women should decide whether to train hard on tough days

If you feel awful, give yourself 10 minutes of training. If you still can't hit intensity, switch to recovery work. Fighting through bad days raises baseline sympathetic drive.

"It depends on how she feels. What we can't rely on are things like heart rate variability because we know that changes with the autonomic nervous system change with progesterone. It's a good indication that you've ovulated because your heart rate variability tanks, but it's not a good indication of what your body can do. If you wake up, I always say it's a 10 minute rule. You wake up and you feel awful and you're like, I really want to do this workout, but I don't know how it's going to go. Give yourself 10 minutes. If after 10 minutes you can't hit those intensities or you just feel horrible, change it. Drop it down. Do something that's more recovery. Do something that's not going to be so taxing because we do have a limited amount of that stress acumen of how much stress we can handle. So if you're going to try to exert it all in a high intensity workout, what do you have left over for the rest of the day? And then that compounds, because if you're always fighting it, then you're going to increase this baseline sympathetic drive because you're fighting the training, you're fighting life. So give yourself that 10 minute rule. If it happens three days in a row, that's okay because it's a very short period of time. It's not going to last forever. So a lot of women have this internal conversation of, I have to do this. And it's really based on some kind of external, they think everyone's watching them. But internally, you don't have to. If you give yourself permission, you end up training better, recovering better, and getting better gains. On the flip side, if a woman is feeling spectacularly good, should she just really push it as hard as she can? Or is there anything about the relationship between the hormone fluctuations of the menstrual cycle and feeling really, really great that training hard can somehow disrupt the cycle? And this is actually kind of the menstrual cycle and feeling really, really great that training hard can somehow disrupt the cycle. And this is actually kind of the old lore, probably myth, I would imagine, that high-intensity resistance training is somehow detrimental to female hormone cycles."

Why 55°F water works better than ice baths for women's cold exposure

Ice-cold water causes excessive vasoconstriction in women. Water around 55°F (16°C) is cold enough to trigger the dopamine response without the severe shutdown that harms women's physiology.

"So the thing with cold water exposure is the whole conversation about ice cold, ice baths, and how cold it is, it's too cold for women. Because when we're looking at that severe immediate jump into that icy cold, it causes such severe constriction and shutdown. So women do really well and get that whole dopamine response and everything. If the water is around 16 degrees C, which is 55 to 56 degrees Fahrenheit. Which is chilly. It's chilly. It's not warm."

Why Dr. Sims recommends Finnish sauna over cold plunge for women

Everyone responds to heat, and women get better metabolic adaptations from sauna than cold. Finnish sauna improves insulin control, heat shock proteins, and serotonin production from the gut.

"Everyone's a responder to the heat. You get better adaptations. So sauna? Yep. Sauna. Hot tub. Yep. Preferably a true finished sauna. Infrared doesn't, it warms the skin, but not the core. Thank you for saying that."

Don't ice bath within 8 hours of lifting — it blunts strength and hypertrophy gains

Cold water immersion after resistance training attenuates the inflammatory response needed for muscle adaptation. Avoid cold plunges for 8 hours after lifting, but doing cold before training may enhance performance.

"If you're going to do deliberate cold exposure, best to not do it in the eight hours or even on the same day after resistance training geared towards strength and hypertrophy."

Post-lifting sauna protocol: up to 30 min with slow rehydration to boost blood volume

Sauna after weight training extends the training stimulus. The mild dehydration triggers EPO production at the kidneys, increasing red blood cells and expanding plasma volume naturally.

"And then you go into the sauna and you are extending that training stimulus because your heart rate is elevated. You're putting your body under stress from dehydration and the body responds in kind of, we need more blood volume. So let's jumpstart that. I love it. Logically watertight, and I'm going to give it a try."

Creatine 3-5g daily for women: benefits for brain, mood, and gut health

Creatine is the top supplement for women at any age, supporting brain, mood, and gut health. Use CreaPure brand to avoid GI side effects from acid-washed alternatives. No evidence it causes hair loss.

"Creatine for women, doesn't matter what age, it's really important. We're seeing a lot for brain mood and actually gut health."

Cold exposure during pregnancy: why caution is warranted and heat may be safer

Cold exposure may increase miscarriage risk in the first 12-20 weeks. Moderate heat like hot yoga (~100°F) can actually benefit the fetus by increasing placental vascularization.

"I'm just biding time there and just saying, please go ask somebody who can give you a definitive answer. Yeah. So we see women who have a high risk for miscarriage, that anything that they do that's incredibly stressful for the first 12 to 20 weeks will put them at a higher risk for it. So being very cautious, especially with cold, because we know that there are so many different nuances. Doing something like hot yoga when you're pregnant is not, there is research, so it's not detrimental. Really? Yeah. Because when we're looking at blood flow diversion that way, when you have slight hypoxia to the placenta and to the baby, there is a rebound effect that increases the vascularization so that the baby has better nutrients. We see this also with exercise and exercise intensities. This is why people are now saying you need to have some kind of blood flow change and increase in core temperature to create these vascular effects within the placenta to improve nutrient and nutrient delivery to the developing fetus. So heat's good. Cold, I'm not so sure of."

Hot yoga (~100°F) is safe during pregnancy but true sauna heat is not recommended

Hot yoga at 40°C (100°F) is moderate enough for pregnant women and can improve placental blood flow. Extreme sauna heat should be avoided. Everything in biology is a process, not an event.

"Hot yoga is not going to the sauna. Hot yoga sits around 40 degrees Celsius, just around 100 degrees Fahrenheit."

The 3 big rocks for women over 40: heavy lifting, sprint intervals, and jump training

Women need jump training, heavy resistance training, and sprint interval training as their exercise foundation, plus 1-1.1g protein per pound of bodyweight daily for longevity.

"In order to build the muscle and keep the body composition in a state that we want for longevity, those are the big rocks — sprint interval training, heavy resistance training, jump training, and protein."

Sprint interval training done right: 30 sec all-out with 2-3 min recovery, not Tabata

True sprint intervals mean 30 seconds maximum effort with 2-3 minutes recovery, not Tabata-style. The goal is full ATP regeneration between efforts, plus 3-4 days of resistance training per week.

"Because I look at the general consensus of what's out there in the fitness world is all based on aesthetics and body composition. So people have this mentality of, I need to be hypertrophy to get swole, and I need to do long, slow stuff on the cardio machine to lose body fat. But that isn't what we're after. We're after, let's create really strong external stress to create adaptations, not only from a neural and a brain standpoint that's understanding it, but also feeding down to metabolic change. Because if you have a really significant high stress, we see epigenetic changes within the muscle that increase the amount of what we call the GLUT4 gates. So, you know, the proteins that open up that allow carbohydrate to come in without insulin."