In this segment of the "Movement as Medicine" series, Dr. Paul Anderson explains the key physiological distinctions between cardiovascular (aerobic) exercise and resistance (strength) training, and why both are valuable for health. He defines cardio as activities that raise heart rate and rely on aerobic metabolism, describing the anaerobic threshold and how training pushes this threshold outward. Cardio’s immediate benefits include a higher calorie burn during the session, endorphin release, and reduced stress signaling, though the metabolic boost wanes quickly after exercise. Early cardio can provoke a stress response (adrenaline, irritability) until the body adapts. Resistance training, by contrast, targets large muscle groups, especially the legs, and creates a prolonged metabolic afterburn lasting 1‑2 days, increases muscle mass, and shifts immune chemistry toward lower inflammation and greater disease resistance. Even modest increases in skeletal muscle confer metabolic health benefits. Dr. Anderson recommends incorporating both modalities, emphasizing resistance work for its broader impact on metabolism and disease resilience, while still acknowledging the complementary role of cardio. He also hints at future topics on muscle as medicine and recovery‑focused exercise.
Chapters
Good day. Welcome to Medicine and Health. I'm Dr. Paul, and we're doing a series on helpful therapies. This part of the series is called Movement as Medicine. So the first little section we want to go into in Movement as Medicine is resistance type of exercise versus cardio. type exercise. Just kind of talk about the differences between them and why maybe a healthcare provider might, you know, ask that you do one or the other or both of these. Now, obviously, for most people, if you're, you know, able to move around and, you know, do things, et cetera, it's nice to have some sort of a combination of these, as you'll see. But the, Many of the experts in the world of, you know, exercise physiology, all that, are now saying, you know, a lot of common sense things like, you know, we're— we have one body, and if we do one type, we're actually getting some of the other. Now, it might be shifted, you know, in proportion, but you actually, you know, because your body is not disconnected from your muscles, it knows what you're doing. So the idea with cardio is that you're increasing your heart rate and you are getting some sort of what they call aerobic exercise, right? So, and there's a whole type of exercises called aerobics, and that's not limited to just that. So you could do that by walking very fast, running, walking on a treadmill, riding a bike. Anything that gets your heart rate moving. If you went out and you played tennis or basketball and you're running around and your heart rate's up, you're getting some sort of cardio workout. Now, there is a thing, a physiological principle that is called the anaerobic threshold in your body. And that is a threshold at which your respiratory rate starts to rise. Now, the idea of aerobic metabolism is that your cells are receiving the nutrient substrates that they run on, the energy processes run on. And in— when they're in aerobic metabolism, they can take oxygen in, obviously, as they do, and work the oxygen and work the substrates from your nutrients all the way down through for example, glycolysis, and then into the mitochondria. And once you get into the mitochondria, whether you had glucose go in or whether you had fats go into the mitochondria through a separate pathway, you also need oxygen in there to run OXPHOS and create energy. So there is a place where you hit a threshold and that Threshold is based on how well trained your body is. So if you have aerobic training, whether it is a fast walk or biking or running or whatever it is that you do, you notice in the beginning, it is not just your muscles are kind of tired, but also you breathe heavier, maybe your heart rate goes up more, etc. And part of that, especially with your breathing, is when you hit the anaerobic threshold, which is where your cells no longer have enough oxygen going in to fulfill the needs to go all the way through, say, glycolysis and then into oxalate in the mitochondria, they send signals out and you get a sort of a little mild acidosis that goes on. And that is your anaerobic threshold. And that signals your brain to regulate your breathing up so that you get more air in. The longer you train, the further out your anaerobic threshold goes. So if it used to be, you know, you would get winded and out of breath immediately or within the first minute or 2, the longer you train, the further out that will go. Right. Now, what benefits physically would, say, cardio do? Well, if you are looking for immediate calorie burn, You have got an immediate calorie burn of about 20% higher than, say, resistance exercise, which is good to know. The thing is, is that aerobic training, or cardio as we like to call it, the calorie burn is during the session and there is not a lot of holdover in metabolic terms. Another thing that cardio does is increases the endorphins in your brain, which are sort of local chemicals, local little messengers that help with a feeling of well-being and, you know, that sort of thing. So it can improve your mood. And then there is also a decrease in central and peripheral stress signaling. And that's whether it's from physical stress or mental-emotional stress, as we've talked about before, they're all perceived the same way by your body. And so, as you go along, these benefits can be felt by your body. You first are going to notice that your aerobic threshold is longer and longer. It takes you longer to get winded. You can do more mileage, whatever way you are measuring things. But a lot of people also just say, I just feel better after I do a workout. Well, part of that is the endorphin dump, and part of it is your stress system, uh, kind of toning down. Now, I've had people, uh, patients tell me early in their exercise bouts that they, um, got actually agitated, uh, when they were, you know, before they were really well trained early on, etc. And what will happen is— so that didn't sound like endorphins and happy chemicals in the brain, everything— they actually got like rageful and angry and all this stuff. Well, early on before you're very well trained, what happens is that your body doesn't understand why you're doing this physical activity. Your body just responds to what your body and your brain are doing. And so one reason, you know, just biologically, that our heart rate might go up fast and our skeletal muscle may start to move fast is that, you know, a bear is chasing us or someone's trying to kill us or something. And so your body has a response to that, especially when you're not very well trained, you know, in cardio or resistance, et cetera. And that is to release adrenaline, also known as epinephrine, so that it liberates substrates for energy and things of that nature, in case you have to run away from a bear or fight someone off or whatever. Now, if you're not, you're just out for a jog and all of a sudden you feel like this rageful feeling or whatever, or shaky, That will go away. Now, there's a couple other things that mitigate it. If you've been fasting and you haven't eaten enough, sometimes that'll happen sooner. But a lot of it is just getting your body used to the idea of training so that then your body kind of goes into this mode of, oh, this is that thing that we do. We're not running from a bear or anything. We're just going out and getting on the treadmill, or we're going for a hike, or whatever it is that we're doing. So a lot of that is about training to get to like the happy brain chemistry, etc. Now, cardio is one big area of helping your body to work better, but then resistance training is more specifically trying to move your larger muscles. So that would be arms, shoulder, chest, legs especially, and then your core muscles that hold your body up. And so resistance training can be done with all of those and That's very, very good for you for a few reasons that we'll talk about. One of the benefits of resistance training is that you have a longer calorie burn. So while cardio will burn up to 20% more calories immediately, it kind of stops after your cardio event is over. And resistance will do things biologically to your muscles so that you have a metabolism change that lasts after the workout, which is very important. So the calorie burn can go on longer. The other thing is that your metabolism can upregulate with skeletal muscle activity resistance work for 1 or 2 days after you have a workout. So your metabolism actually goes up. People are always worried about their slow metabolism or they're recovering from a disease and they have slow metabolism. One way to get your metabolism back in the game and to kind of kick it up a notch is to do some resistive exercise. Now, in our series on movement as medicine, we're going to talk about, you know, healing up after injuries and other stuff like that. So we'll save that for that little section there. The other thing that resistance training does is increase your muscle mass. Now, it turns out that you don't have to be big and giant and, you know, have giant muscles all over to have an increase in muscle mass that makes a biological and a health difference for you. What we're finding now is that people that can work their skeletal muscles even a little more than they used to have chemistry shifts in their body that become less inflammatory, more prone to the right kind of immune chemistry, more prone to resistance from disease, more prone to all sorts of good things. And the important part about that is, yes, you'll get some of that with cardio, but you actually get more with resistance exercise. So then the next question that people often come up with is they'll say, well, you know, I'm not a powerlifter, or, you know, I've been sick, or I've whatever, or I'm just changing my life now and I want to get more active. Well, one of the best things that you can do is to move the biggest muscles that you can up to the point that you tolerate it. And it turns out that the major large muscle groups in your body are in your legs. So by even a sedentary person, by starting to stand and sit down more, for example, or somebody maybe who's a little bit trained or does a lot of cardio and they start to do a little bit of leg work and some squats and things like that. And then if you can do the other bigger muscles, that's great. But the legs have the most potent impact on resistive exercise initially because of the biggest mass of muscles. Then you go to your core muscles and your arms, etc. So you don't have to do a lot that's different for that effect to come about. So you get a metabolism increase, you get a longer caloric burn, and you also wind up with more muscle mass as you Go along. Now, there is the idea that muscle itself, muscle's metabolism, is actually medicine. That's going to be our next topic that we're going to talk about, so we won't get too much into metabolism here, except to say that by moving your body and by working the bigger muscles, you're doing resistive exercise, and that is very helpful. for your metabolic health, for your long-term health, your resistance to disease, etc. And even in things such as, you know, some bad infections and cancer, etc., you can have a better recovery if you're doing some kind of resistive type exercise. Now, when we get to recovery exercise, we'll get into the details of that because obviously, if you've just been through surgery or you've been through some other problem, you're not going to go right back out. you know, start powerlifting or something like that right away. You have to kind of work into it. So we'll get into that too. So what about, um, you know, if, if you had to make a choice and you had to do one or the other, what would help? Well, many experts that I've read, and I would agree with this because the body is not disconnected, will say do resistive exercise because your heart rate's still going to go up. Well, your, your, your brain knows what's going on now. When I was young, many, many decades ago, and I was an athlete, when we were training, they would always say, you know, you got to do a cardio portion and a weight portion and keep things in balance. That's probably ideal. But you're going to get a little bit resistive exercise doing cardio, and you're going to get a little cardio doing resistive exercise. But really, the resistive exercise and its impact on your muscle as medicine for your body. It's most important. All right, I'm Dr. Paul Anderson. Please like, share, subscribe, hit the notifications, because sometimes we get marginalized on the, uh, on the apps, uh, and we'll get on to our next, uh, next section here coming right up.
