HIIT vs. Sprint Training: What Women Over 40 Need to Know | Dr. Stacy Sims

0:00 Now, Stacey, in your book, you talk about three different types of exercise. At this point, we talked a lot about lifting heavy. Um, but I think there were two other things in there that that you you said are really important for um women at this stage in their life. >> Yeah. And this is the polarization aspect where we're talking about highintensity work. We're talking about highintensity interval training and a subset of that that's called sprint interval training. explain what that means.

0:30 >> Definitely. So, when we hear the buzzword of HIT or highintensity interval training, we think of things like uh 45minut boot camp where someone's taking you through all these circuit exercises and your heart rate's high, you're completely gassed. Or you might think of a class like Orange Theory or F45 or CrossFit. All these kind of things were talking about high intensity. That is not what I'm talking about. When I'm talking about highintensity interval training, I'm talking about 30 minutes at the most with the warm-up and cool down. And in that, you have maybe 1 to four minutes where you're getting your heart rate up to around 80 to 90% of your max or on a rating of perceived exertion of 1 to 10 with 10 being max. You're looking about a seven or an eight for that interval.

1:20 And then you have, you know, one to four minutes of recovery where you're bringing your body down to a really easy state before you hit the next one. And most people can when they start off might do one interval of 2 minutes and they're like, "Oh, that was so hard. I can't do another one." And that's fine because we want to build up. But we don't want it to be 45 minutes where your heart rate is at 70% or your rating of perceived exertion is at an eight or nine but in reality it's the fatigue that's invoking that because then you're squarely in that moderate intensity again. And what happens with moderate intensity is it increases cortisol. Now some cortisol is good but when we're in pmenopause we are already in a very what we call sympathetically driven state. So that means we're tired but wired. Our baseline cortisol is elevated. And when our baseline elev cortisol is elevated, we have a stimulus to put on fat, keep residual inflammation, bloating, can't sleep, can't come down, can't relax. So if we're doing true highintensity interval training and we're polarizing where we're hitting those intervals, that's you know that 80% or more and then the recovery aspect is 50% or less.

2:37 So, you're really going hard when you're supposed to go hard, going super easy when you're supposed to go easy. You have a subsequent rebound response after exercise where your body reduces cortisol, increases growth hormone, increases testosterone, and those things help with reparation. They help decrease some of that deep vicerial abdominal fat or that minnow pot that people talk about getting that belly fat. So, there's a feedback mechanism that goes on that your muscles are talking to the fat and saying, "Hey, you know what? We don't need you. We don't need you fat.

3:15 Go away. We need to be able to make our muscles really strong. We need to be able to overcome this interval stress." And so, it feeds forward to having better body composition, better muscle morphology, meaning that your muscle function. And then when we're looking at it from a like a sleep point of view because you've done this really polarized training, then when it's time to go to bed, you have an increase in what we call your parasympathetic drive.

3:44 And that's what we need to get into a deep sleep. So if we do this maybe twice a week, then we end up with better sleep patterns, better messaging to our body for for increasing our lean mass and decreasing our body fat. So Stacy, I think everybody listening to this is um saying, "Oh, so this is the exercise that really does, you know, cut down my belly fat as per like the ad you see across the internet everywhere. That sounds pretty good, but I didn't really understand at this point what it was.

4:13 Could you like um give us an example?" >> So if we're looking at highintensity interval training, um I'll take it for someone who is more fitness class-based. So, we can talk about it as being every minute on the minute you're doing five burpees and the rest of that minute you're recovering and you do that five times. Or we can talk about it as you're on a bike urg or a rowing urg and you're going to hold a steady state for 2 minutes and then you're going to just get into a nice relaxed pace for 3 minutes, maybe four minutes. Really recover and then do the 2 minutes again.

4:52 And you won't do that any more than four to five times when you're super fit. When you're first starting out, it's very, you know, very short amount of time where you're doing that highintensity work. Um, then when we get into what we call sprint interval training, I'm not talking about running sprints. That's the misconception. Everyone's like, I can't run. I can't sprint. Sprint interval training is all about 30 seconds or less going as hard as possible. So, you're hitting that nine to 10 on a rating of perceived exertion. You feel like you're going to throw up at the end, but then you're fully recovering. So, you might be walking down a hill that you've just tried to sprint up or you might um pedal really lightly on a bike urgy or thrusters or some other kind of movement that you might be working on in the gym. So your recovery time might be 2 to 3 minutes bringing everything down because we want to be completely ready to go for that next 30 seconds. So it's really really intense exercise. It's really high high intense exercise but the benefits for that is then we end up with better blood vessel control which helps reduce hot flash responses as well. We have a epigenetic change within the muscle. So this means that we're um changing the muscle itself to be able to pull more glucose in without insulin. So it helps with that insulin resistance that comes with pmenopause.

6:30 And again, we have that subsequent post exercise response that then allows us to drop cortisol and increase our parasympathetic responses. So that means better sleep. People are like, "How do I do sprints?" like I've never like it's been so long since I've gone that hard. How do I do sprints? It is something that you want to phase in. So maybe after you've done 20 minutes of resistance training, you do a couple of box jumps. So that might be, you know, three or four box jumps and that takes 20 or 30 seconds. You're going from the floor and you're jumping on up on top of a box. So it's a squat jump up. Um, or maybe you're just doing squat jumps in place where you're squatting down and jumping up, squatting down, jumping up, cuz then you're getting some bone stimulus as well. So, it's all about how hard can I go for those 30 seconds. One of the other things I like are battle ropes. If you've been in the gym, then you've seen the battle ropes. They're the long really heavy ropes and people are just trying to create a wave with them. It's a total body really hard exercise. you try to do that for 20 or 30 seconds, you're completely gassed. So that's another way to think about it.

7:48 >> And Stacy, on the sprint interval training, again, you're looking to do like 30 seconds of this, then rest. And again, this is four or five times, and that has achieved the the objective. >> Yes. And at this point, it's all about intensity. It's not about volume. Because I hear women all the time who come from an endurance background, meaning that, you know, they've run marathons or half marathons or, you know, they they really love their spin classes or, you know, they're used to going to the gym for an hour and a half and they're saying, "How am I going to get these body composition changes I want?" If you're telling me I really only have to work hard for 2 minutes, it's not about the time. It's about the intensity and the physiological response your body has to that intensity.