Why HIIT May Be Failing You

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What are you waiting for? Good night. HIIT, high-intensity interval training, it may be failing you, failing to burn the excess total body fat and particularly the VAT, visceral adipose tissue, which means belly fat to you and me. Spoiler alert, there are two reasons why, and I'm going to give them to you right now. Number one, You aren't actually hormonally in a place where you'll benefit. Number 2 is you're doing them—intervals, that is—outside a sweet spot that is optimal for results. All the details inside.

I'm Debra Atkinson. You're listening to Flipping 50. I started this podcast over a decade ago to answer questions about fitness in menopause and beyond before you knew to ask them. The goal to help accelerate your results with science and the practical application of proven protocols while living your best life. There's no more powerful health influencer in the world than a midlife woman. And it's not just about you, but the 3 generations that you influence. My unique 40-year career, including being a university senior lecturer in kinesiology, an industry subject matter expert, and an international speaker, to founder of the first and the only exclusively made for menopause and beyond fitness membership in the world. Every week I interview experts behind the scenes and the science of optimal hormone balancing fitness and longevity and share answers to our community's questions so you can have the vitality and the energy that you want, need, and deserve.

Okay, so let's unpack this. All right, so truly high-intensity interval training has been broadcast high and low in praise for supporting visceral belly fat dissolution or dissolving for decades now. Actually, it's kind of the late '90s this came into play, and for women in post-menopause It's been proven. However, it's not just across the board, all women will get these benefits, all women in postmenopause will get these benefits. You've got to actually be feeling pretty good in order to step in to losing belly fat from doing something. So in other words, I'll say it the opposite way. If your adrenals are shot, you're trying to push through because you've gained some belly fat, but you're known for pushing, pushing through, burning the candle on all ends, not getting enough sleep, maybe not getting enough rest, working around the clock, and you're trying to do high-intensity intervals, but your adrenals really are screaming, stop, just rest, go to sleep, take a bath, get in a sauna, do something else. Please, please do that. And you're ignoring them. That probably won't work. I'm going to spend the rest of this episode, however, talking about number 2. You're doing high-intensity intervals and you're really ready for them. You're feeling pretty good energetically, feel great. You do a workout, you're energized after the workout, sleeping well, libido is pretty good, your appetite is pretty good, but cravings are non-existent really for you. Kind of figured things out. But you're still not seeing the results that you want from them. What's going on? We're going to spend our time going over that. So quickly wanted to address that adrenal issue because please, please, please realize that there is a high percentage of women within our membership who— they're not ignorant. They're highly intelligent, highly intelligent. And I would say by the time we're 50, 60, we're also fairly highly intuitive, wouldn't you say? We've been there, done that. We've seen it. We hear 20 and 30-year-olds say things and we're okay biting our tongue because we get it. No matter what we'd say, they need to figure it out themselves and they will. And it's probably better for them to learn it that way. That's great intuition. Right. And there would have been a time when I can't let that go. I'm going to get in there. I'm just somewhere else right now. And I'm guessing you're getting there too, or you're there and maybe you were there way ahead of me. Let's just both admit that's probably true. So let's be sure that you're in the right place to do HIIT. Why isn't it working if you're doing it? Well, a couple of things I got to the bottom of really some of the mechanisms why it's working, why it's not, and what's going on. So we need to really talk about this. So glucose metabolism during high-intensity exercise or high-intensity interval training. But I want you to think about this too. Your weight training is actually high-intensity interval training in a way. So if we have you wearing a heart rate monitor, and most of us are wearing one. You know, I will lift weights and every once in a while I'm lifting weights, I will get this message like, you should relax, relax reminder, you're a little stressed, how about you take a deep breath? Like, how about you mind your own business? That's kind of what I'm thinking. But, you know, I don't care if it beeps at me. But there are times when your heart rate, if say if you do a set of squats, a set of heavy squats, I'm not talking you have to be doing plyometric jumps or you have to do a cardio between your strength training sets. In fact, I really despise that and that direction or those kinds of boot camp classes. They negate results in either way. You're not getting optimal cardio, which is really what's going to determine your longevity. You're not getting that bump in VO2 max that you would. And you're not getting complete muscle fatigue. You may think, oh, I'm burning a lot of calories, it's really hard, it feels hard, I did a hard workout, so it was good. Hard is good, right? Not always. Not if that wasn't what the workout was supposed to do, and not if you didn't ring the bell on both sides. And generally you don't when you're going back and forth and back and forth. You're not recovering in between. You don't get your capacity of speed or resistance. If you're going against resistance and not doing speed for that cardio, or it's really anaerobic interval, or you're not getting as heavy with the weight that you're able to lift, or the number of repetitions alternatively that you otherwise would be able to get, you're just kind of meh on both. And so you're not gonna If you were training for the Olympics and you had a meh workout, your coach is probably going to have something to say about that. And I'm guessing it's not going to be good. So consider me for a moment your coach. And let's just say we want really quality workouts every time. We want to train the good ones. When you start putting out junk, it's time for you to leave, right? And go rest and go recover so we can come back, train the good ones again. If you're just putting in more time doing more stuff you're probably not getting more fit, and you may actually be inhibiting yourself. But let's talk about glucose metabolism during high-intensity exercise. The classic form of all-out HIIT, meaning you dump it all, you like totally to exhaustion during every HIIT bout— it's called the Wingate test, and it's been around since forever, like forever since I was an undergrad. The Wingate test is— was a really popular protocol done a lot to look at fitness levels. After about 3 to 5 minutes of warmup, what happens is the subject will cycle. It's usually on a cycle, and lab tests are done using cycles because it's so easy to plug you in. Like, we can put— we can have you breathe in oxygen, we can have you wear electrodes, we can look and measure so many things in a controlled environment where That's not as easily done if we have you doing some kind of aerobics. We have you on an elliptical, we have you running on a treadmill even. It's not as easy. It's done, but it's not as easy, certainly because things are flopping around. There's that resistance of gravity. It's just a little bit easier on a metabolic cart pulled up to a bike. So know why we say cycling. We're actually not referring to female cycles today. Okay, so after about 3 to 5 minutes of warm-up, the subject will cycle for about 30 seconds at maximum effort, like going as hard out as possible against standardized resistance. And that means that we're putting it at a level like it's going to be— this is, this is the resistance it's going to be. You're going to push hard. Typically there's 4 to 6 Wingate tests performed separated by 4 minutes of rest. So we do that 30 seconds of all out, and then we recover by 4 minutes of rest. And that could be sitting still on the bike, or it could be beginning to barely pedal just a little bit, just to move and circulate for a total of 2 to 3 minutes of maximal exercise, right? That's spread over 15 to 30 minutes with warm-up and cool-down. But the work time, right, the work time, it's a total of 2 or 3 minutes, 30 seconds, right? Done by how many? 4 to 6 sets of them. So the workload time is not very high. You need to pay attention to that, right? So, so many times we think we'll hit A little bit of it is good. So I'm going to, I'm going to do it for an hour. I'm going to torch tons of calories, right? Hello, have you done that? Yes, you have a heartbeat and you're alive, right? And you're probably female, conscious of your health and body composition, right? I know it's so tempting, but it's not the way. It's the way we tend to think, but it's not the way. So that is all-out cycle ergometer form of HIIT. It's also referred to as sprint interval training. And I have to tell you this because we're going to do a couple more episodes coming up about sprint interval training versus high-intensity interval training. Everybody seems to think sprint interval training is something that is unique and different, and sprint interval training doesn't really have a definition all its own. Like, you don't look it up or go to science and say, what is sprint interval training? Well, in one study on postmenopausal women, it was bicycle testing, and it was 8 seconds of sprinting followed by 12 seconds of recovery, done for a 20-minute total, bookended by 8-minute warm-up and 8-minute cool-down. So there's a lot of 8s in this study, right? But that's it— 8 seconds of sprinting, 12 seconds of recovery. Repeat, repeat, repeat. That was sprinting. In other forms, someone will say, want you to do sprint interval training, and that is like 15 to 20 seconds of sprinting as hard as you possibly can and then recovering completely in between. And someone else will say, want you to do this, you know, 8 unique times and recover, you know, 3 minutes in between. And there are unique protocols is what I'm trying to point out, that if you're referring to sprint interval training, I have to say, what does that mean to you? Because everybody has this different idea or concept on what it means. Similarly, I coach trainers and health coaches and to build their business with the Flipping 50 menopause specialists. And, you know, before we start, I ask, you know, what's your definition of success? So I don't, I don't want to help you build a business that is, you know, 35 to 40 hours of one-on-one kind of coaching if that's not your idea of success. We have to know what it looks like. Like, how much do you want to work? How much do you want to make? Do you prefer to work with one-on-one? Do you want to work with groups? How do you want to— how do you see this playing out that you love getting up in the morning every day to go to work? So same with you, right? So just you have to define, you know, what is it that you're really talking about and realize, please, that there is no universal definition of high-intensity interval training. There's no universal definition of sprint interval training. And we're putting out a book. For women in menopause so that you can identify which of those. And some of this content here is actually from the research for that book, and it'll be short, it'll be consumable, and it will include protocols that you can actually test for yourself and say, huh, that works, this feels good, I like this. And by the way, this isn't just about total body fat or visceral adipose tissue or belly fat. This is about your brain health. The brain really gets turned on and loves— it's like your foreplay for your brain, right? So it gets turned on when you do high-intensity interval training in a way that is different than, say, you go for a walk. It's good for your brain too, more in a de-stressing kind of way. But this really like plugs in those electrical outlets up here. In a way that other things don't. So know that that is true. All right, in intense exercise— when we say intense exercise, it's relative, and I'll give you what feels like, but we're talking about intensities over 80% of your VO2 max. Let me tell you where that is. That is a point where you start asking, how much longer are we gonna do this? Like, and you're not asking in a complete sentence, you're saying, how much longer, right? You're talking between breaths. It's work. You're very aware it's work. It's no longer just a walk and a stroll through the park. 80% is pretty hard. You're going to know it's hard. Unlike at lesser intensities, glucose is the exclusive muscle fuel. So your body is burning carbohydrate for the fuel because it is happening so quickly, right? And when your body is forced to do something really hard, really fast, it's going to go to the most available resource. It's not going to— it's not going to go deep in the crowd. So if you're running a marathon, sprinting to the finish line, you really have to— you need to choke down something for your throat is so dry. You're going to take a water bottle from that person right there in the front row. You're not going to go to the back row and say, hey, I want the one you have. No, no, no. Just who can put it in my hand? Easy. Your body really is doing the same thing. It's like, I'm not going to go into fat storage and get that because to break down the fat molecules, to put it into energy, and to number one, have to go get it out of fat cells— too much work. Don't have time to do that. We need to get all the working blood flow oxygen delivered to the muscles, and I need to do it fast. So conversion of glucose— carbohydrates are readily available. It's stored in your muscle for that purpose until it's gone, right? And that's when you have to be probably eating on the run. But glucose is the exclusive muscle fuel. It's why we can't work really, really hard for a really, really long time. Your body can't continue to supply that fuel. You can't continue to make that ATP, which internally to your cells is like, give me the fuel, then go. Give me the fuel, then go. Catecholamine levels. What the heck did I just say? Catecholamine levels rise markedly, causing glucose production to rise 7 to 8 fold while glucose utilization is only increased 3 to 4 fold. Okay, in people without diabetes, that's you and I, for the majority of you listeners, there's a small blood glucose increase during intense exercise that increases further immediately at exhaustion, and it persists for about an hour. So if you and I did a high-intensity interval training session, it was really high, we had on our continuous blood glucose monitors— I'll tell you how to get one at the end If we have that on, we're going to see a little bit of spike while we're in that workout. But we're so busy sprinting and huffing and puffing and sprinting and huffing and puffing that we're probably not paying much attention. But afterward, we're going to be walking out the gym thinking, oh, this is so great. Oh my God, my blood sugar spiking. It's okay. You should expect that this happens. It's going to be elevated and then it's going to come down because You released all that blood sugar to use. Okay, plasma insulin levels rise, correcting the glucose level and restoring the muscle glycogen. And that physiological response would be absent in somebody who has type 1 diabetes. Remember, type 1 doesn't actually make insulin, doesn't generate it. They are reliant on it. Type 2 makes it, but the cells are not receiving it, right? It's like insulin resistance on steroids. It's type 2 diabetes. Let's talk about aerobic endurance and high-intensity exercise. Look at the two. HIIT is effective in improving aerobic endurance. HIIT is effective at improving aerobic endurance. That means that marathon runners also do high-intensity interval training because twofold, it helps improve their aerobic capacity without having them have to have so much training volume that is wear and tear on the joints, does break down lean muscle, right? And they know it. So, they don't have to do as much, but also can raise the roof potentially and get them a little speed because they're able to do more speed training in those short little bouts, right? So this is really important to understand. So it's effective, but we can't say the opposite. You can't go run long and expect that your VO2 will improve, right? So that chronic cardio in that middle zone doesn't increase your high-intensity interval ability or fitness level, which is equated to your VO2 max. That's an important distinction. In one study, 6 all-out sprint interval training sessions over 2 weeks improved. So when I say session, within the session there were probably 4 to 6 sprints going on, right? So 6 all-out sit sessions— was a lot of S's— over 2 weeks. So 6 sessions, they probably had what, 3 each week? Improved the mean cycle endurance time to fatigue while cycling at approximately 80% of pre-training VO2 max by 100%, meaning they could cycle harder, longer And at first, they could only do it 26 minutes. 2 weeks later, 2 weeks later, they could do 51 minutes. That is crazy. Now, I'm— total disclosure, that is not a study that was done on perimenopausal women. But we know now, at least from this, what's possible and the benefits from it. This required a total intensity exercise time of 15 minutes, 15 minutes over 2 weeks of training, right? The hard stuff, the total training time commitment. So the time getting on the bike to getting off the bike, 2.5 hours over 2 weeks. All right, so pretty good return on investment. In another study, a less intense version of HIIT— it was just 6 to 10 cycling bouts of 30 seconds each at— this is going to sound like, are you kidding— less intense, at 125% of the power at VO2 max with 2-minute recovery produced a similar improvement in VO2 max after 4 weeks of training. So it took a little bit longer if it wasn't as hard. So I want you to realize that again, if you start getting wishy-washy, you're not going to see the results as quickly. And you may get so wishy-washy that you're not recovering completely, and then it won't work at all. But you will see results if you go a little bit slower or you can't go harder. By the way, hard is relative. So don't ask me what speed you have to go., right? Don't ask me what resistance you have to go against. It's up to you. What you get breathless at is totally your business and nobody else's, right? Except your coach. If I was your coach, I would want to know. The less intense HIIT required only half the intensity but double the repetitions of the sit. Now, this, I think, is dangerous information. May be more practical for the non-athlete was the conclusion of the researchers. But watching thousands of women come into and out of our membership, come into and out of programs with varying levels of success, what I've noticed is that those who do not as hard but go longer and they get their volume not from intensity of heavier weight, more sets, but in terms of more days a week, longer sessions. I'm going to throw in additional intervals. That doesn't usually pan out as well because they're really tapping into cortisol and adrenals and getting into muscle breakdown. And then we also think I still don't want to eat much. I don't want to overdo protein. And we're making mistakes coming and going that end up washing out the best of intentions. We do it unintentionally, partially because of the conditioning we've had for decades. So I want you to realize, if you get pulled back into this, it's very easy to allow this to happen. After high-intensity exercise, insulin sensitivity is typically increased, right? And that's exactly what we want. Whether it's strength training or it's high-intensity exercise, insulin sensitivity is increased just by an acute bout of exercise. The body may require less insulin to utilize glucose effectively, which could lead to a slight rise in insulin levels during recovery as the body replenishes glycogen stores. Why does that happen? Think about it. So you've used the glycogen in your muscles, like you poured it out, poured it out, right? In between intervals, they restock. It's kind of like they reload, like you were ready to pull the trigger again if you give yourself adequate rest. If you don't, you'll know in consecutive intervals you don't get as far, you don't go as fast, you, you're just not allowing yourself the recovery. But afterward, now you've really depleted all of it, and so we have to put it back in. So your glucose levels rise for that to happen, and then the insulin rises because that's circulating, and the insulin comes in so that— get that out of the bloodstream, let's put it back in the muscle until the muscle bank is full. Then will potentially go to the liver, and then after that it will go to the fat stores, right? But let's hope we don't have that happen because you're resupplying and you're moving regularly, greater muscle mass. So go you, right? So the lower the conditioning level, the more insulin is likely to be increased. Right? So you have to be cautious about this one, and this is where the kind of intervals you do will really matter. The longer the activity level, the more insulin is likely to be secreted after exercise. The shorter you keep that activity level— 10 minutes and 15 minutes of sprint interval training can do you more good because you won't get that respond or rebound higher insulin level. So it is twofold: short intervals, get yourself to breathlessness fast, recover completely before you do it again. Keep those intervals short, and then keep the full session short. 10 to 15 minutes. If you do that more frequently, you're going to get better results than saying, I can't do this very often, so I'm going to go for 30 minutes today. Potentially, you will have actually hit your sweet spot and then pulled back out of it and not only not got more return on investment of time because you hit a threshold, but you will potentially get— go backwards and get fewer results. Whole different way to think about your intervals. So if adequate recovery does not occur between the intervals, there may be greater elevation in your stress hormone. And what do those stress hormones do? Cortisol breaks down muscle. What does the insulin do? Increases fat storage. Now temporarily, you're going to have that dance between glucose and insulin. If it's short-lived, you're going to be okay. But if you get more insulin released, you're not so okay. You're missing some of the benefits. So that if it helps you remember, sprint is shorter, SNS, as opposed to HIIT, which may be the same duration, it's just words, then great, use it. Sprint interval training just means go all out 15 to 20 seconds at most. And therein lies your task, is finding the activity that will do that. Okay, so really important. So either keep your intensity high, the duration extremely short, or make this a longer session with up to 4 minutes between all-out bursts of 20 seconds, with a total 20 minutes of interval rounds. Including warm-up and cool-down to make it a maximum 30-minute session. So think cool-down, warm-up— they've got to be longer, right? At least your warm-up has to be longer, especially if you're going to do high impact, like you're sprinting, you're jumping, you're plyometric exercise, because it's much harder on you. But even if you're doing something low impact, like you're using an elliptical, trainer, you're using a rower, or you're on a spin bike, there's still a little bit more muscle tearing going on because you're going so, so fast. So realize that that's there, definitely less, but it is still there. So the key to HIIT and not letting it fail you is keep it shorter. Keep your intervals shorter, recovery long. Do fewer of them. 4 to 6 is maximum. But hey, you know what? One or two counts. If just you go for a walk and you do a two-breathless something for 15 seconds at the end of it, even that counts, right? And you're potentially increasing your longevity by doing that. We've got a couple resources. The references are in the show notes today if you're interested. Let me know what your questions are about sprint interval training, high-intensity interval training. Know that we have a book coming out. We'll put that in the show notes once it's complete. Can't wait to hear your questions, and I want to hear what you're using because I think this one gets women stopped sometimes. Like, I can't run, I can't jump, and it's hard for me to get my heart rate up that quickly, so I never get out of breath. What could I do? So I want to know if you found a solution to that. What's your solution? How are you getting breathless? So by the way, for those of you who need low impact, mentioned the elliptical, I mentioned a rowing machine. They, they require equipment. I know it gets a little tricky and you've got to get a little creative, but if you can get in the water, do water running, water actions, you can still be upright if you don't swim, but water can be a great environment to be just a little bit safer in order to get this. But any activity can be high-intensity interval training or Sprint interval training. What are you waiting for? Let's start Flipping 50 today.

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