Improving My Blood Pressure With Anaerobic Interval Training
heart rate / cardiovascular | sports & fitness
Siva Raj noticed his blood pressure rise after he turned 40, which was a wake-up call since he watched his father have three heart attacks in ten years. He then tried to figure out how to normalize his blood pressure, so he began doing anaerobic interval training. In this talk, he shares his success doing the training using Revvo, a small exercise pack.
My name is Siva Raj. I’m the founder and CEO of Revvo which is a Boston based startup, building a small exercise pack. Very excited to be here to tell you about how I improved my blood pressure through anaerobic interval training.
First up, just quick poll have any of you ever measured your anaerobic threshold or Vo2 max fitness level. That’s a little bit more than I usually see, so given the audience that kind of makes sense.
So this all happened a few years back when I turned 40, and 40 seemed to have come with some consequences I did not expect. So I started to see my blood pressure rise, and 120 over 85 it’s usually considered mild pre-hypertension, but for me it was a bit of a wake-up call, because I had seen my dad have about three heart attacks in 10 years, so I knew what was going to come down the line, and so I was a bit curious about what I had to do. So it got me thinking about what I should be doing to get my blood pressure normalized.
One of the things that I kind of knew from previous work was that fitness and blood pressure correlates with each other, and so typically, when you have lower fitness as you see in this chart there is a green line and start seeing the blood pressure rise at about at the age of 40. Normally it happens at 50, and if you’re fitness level is high and it seems to hold your blood pressure off from rising until you get to about 60 or so. So there seems to be an underlying correlation, so I was very curious to first, measure my fitness level and see if I can improve it and thereby improve my blood pressure also.
So fitness is a very broad term, so I wanted to kind of define what I meant by it, and so I’m using a scientific definition of fitness, just multiply your measurements of VO2Max and METs and METs is 3.5 times your VO2Max. And at the very simple level, if you’re fitness level is low, it means that your capacity for physical activity is constrained. So even simple tasks like walking up a flight of stairs becomes very challenging. If fitness level is high, it means that you can cope with more challenging tasks like running a marathon or doing other stuff.
How is fitness and blood pressure correlated? So, fitness is a function of two things; VO2Max is a function of how much oxygen can your body actually supply to muscle. That’s transported in blood, so it’s the cardiac output that matters. Then, how efficient are your muscles at extracting oxygen from the blood, so that’s the muscle oxygen uptake.
So when your blood pressure increases, it increases the resistance to blood flow, so it reduces your cardiac output and therefore reduces your fitness. So these kind of inversely correlate with each other. And so the first thing I wanted to to literally was measure my fitness level and then see if I could influence that through exercise and see if that could therefore have an effect on my fitness level as well as my blood pressure.
So traditionally to measure fitness is to go to a fitness lab and then you get a VO2Max test as it’s called where you have an increasingly measure of intensity as your cycling or running, and the measure of oxygen uptake and respiratory gases and that estimates your fitness level of max you can obtain.
Now I want to be able to do this regularly to measure the impact of the change I was making. I took what I call the indirect approach where I measured the energy expenditure from a bike in terms of Watts, and I used all the latest heart rate monitors and see if I can measure my heart rate. So in this graph you can see my initial attempts to try and capture two data sets. The purplish line, the dotted line is the wattage from the bike as I’m doing it with training. And the lightish line is the heart rate data from the wrist base heart rate monitor.
So one thing that I realized early on was that the heart rate data and the energy expenditure was actually correlated so you’ll see in the early parts, the heat rate leaps a lot when I finish my activity. And then towards the middle or the end of the exercise it starts to catch up. So I switched to a chest strap and that immediately kind of give me fairly clean data. So here you’ll see the heart rate in yellow and the power output in Watts in blue and then you’ll see my heart rate raise very neatly at the moment I start pushing up my intensity and then it starts to decline when I stop. And so that kind of gave me the two data streams that I wanted to be able to use to estimate my fitness level in reasonable accuracy.
So my first estimate of fitness of some confidence was August 26 2013 and my fitness level was 11.9 METs, which basically meant that I was less fit than the average 50 year old healthy male. So it was no surprise with issues that should have come later on. And so my goal firstly was to be able to improve that and maybe try and see if I can push it up to being comparable to a 40 year old and maybe then try if I could take it up further.
So I started doing very intensive activity, and from the training that I had I picked interval, because I knew it was twice as effective as conventional training and pushing fitness up. I did that three times a week, 30 minutes a session. I was pushing VO2Max hear rate, so I knew it was pretty hard. I lost some weight I was boarder line obese then.
And I did that for six month and my fitness level did not change very much. My blood pressure didn’t drop very much either. So there wasn’t much of an impact on the things that really mattered to me, which was my blood pressure and fitness level. So I now had my fitness measure kind of working very nicely, I was able to experiment with different approaches. And one of the things I wanted to do was to see if I could push the intensity up because I had also seen a lot of the work that had been done, that heart intensity tends to have a bigger impact on your fitness levels so it’s more likely to improve it.
And so it was a little bit of a struggle to be able to push the intensity up without sacrificing the amount of time I was spending exercising. So it was a little counter intuitive to me as well for me to be able to do that, because you know I always believed you had to work out a certain amount to see a benefit. But I kind of valued my own kind of conceptions and switched trying to push, as you’ll see in this graph, the first kind of six months it was about 190, which was below my anaerobic threshold and endurance limit. And typically it’s very difficult to sustain high intensity for long periods of time continuously above the anaerobic. You can do that below, so by definition, that’s the point at which you stop being able to do that.
And so when I switch from 60 seconds to about 30 seconds I was actually able to get 50% higher than the level I reached until then. So I did that for a few sessions. And within weeks I could see the difference in terms of the impact on my fitness level. So it was 12.9, 20th Jan, the 5th of Feb was when I shifted to anaerobic, 18th Feb 12.4, 12.7 so it was a pretty consistent increase.
Very quick within six month it had barely moved, and within a few weeks it started to shift automatically and my blood pressure dropped as well almost immediately. Even though there was barely any difference in my weight in this kind of timeframe.
So what is the anaerobic threshold and why does it seem to kind of give this surprising very interesting result. So in the muscle uptake of oxygen kind of stops being efficient at a certain point, and that’s where your muscles switch the stored glycogen which doesn’t usually last very long, so it’s only a very short amount of supply and I think of it as (unclear 0:24) supply, so that’s what it’s meant to be, it’s high intensity work out but very short.
And so when you push yourself above it, it challenges your body to improve.so your muscles get more efficient and challenges your cardio vascular system so you get a whole body improvement in how your physiology functions. So since then I’ve in fact continue to increase the intensity, and again each time I’ve done that I’ve had to trade off the amount of time. Now I’m doing a 10 minute program workout that I do. It’s 20 second intervals and I do about 3 to 5 intervals per session. And I started at 11.9 as you saw which is less fit that the average 50 year old, and now I’m about 16, but I’m fitter than the average 20 year old which I’m a little bit about.
So my key takeaway from all of this is kind of basically three things, one is that accurate data really really mattered for me and so I think with a lot of the devices out there we really don’t know how accurate they are and in this case I actually had an opportunity to measure it. And getting accurate date made it possible for me to do the things I did with the precision that I could do and without this precision it would not have been possible.
The second thing that mattered was actually measuring fitness repeatedly so I could see the effects of my exercise on the metric that exercise actually really meant to influence, which is your fitness level.
The third thing of course was being able to push the intensity, particularly above the anaerobic, which seems to be a point at which you start seeing much more quicker adaptive responses from your system. And of course, pushing it further seems to be better. But that seems to be a very good point to start for everyone.
So this technology and the learning from this led to the creation of Revvo, so a lot of what you’re doing with Revvo has now been linked. So we have a booth out there if you’re interested in learning more and please feel free to come over and chat.