In the last post, I talked about what the various heart rate zones are, how they are most simply calculated, and then talked about why it is important. I want to recap the last point because it is so critical. When endurance athletes talk about Zone 3 and Zone 4, they often refer to them as the grey zones. This is not to say that there isn’t a time or place for work in Zone 3 or Zone 4, but if you’re going to venture there you should have a really good reason for doing so, otherwise the time you are spending exercising will burn calories, but will not do a lot for improving your fitness or, in technical terms, your aerobic threshold. I know this seems ridiculous, but if you’re a runner, ask yourself, when was the last time you made a significant gain in your running times? If the answer is “a long time” or “I don’t remember” I’m sorry to tell you that all those hours and miles you’ve put in haven’t been as beneficial as they might have been. On the other hand, they were not for naught and they have taught you excellent habits of discipline. Now let’s make them really pay off.
Step One: find your zone
I showed you the super simplistic calculation for HR Zones in the last post. If you don’t want to delve further, use that calculation. There are several other ways to calculate your Zone 2, including the Karvonen Formula, the Maffetone formula and the Friel formula. If you’re interested, drop me a note and I’ll gladly explain further. Or, if you’re so inclined, I put together an Excel spreadsheet that calculates them for you. This is a link to the spreadsheet. Personally, I like the Karvonen Formula, which uses your age to calculate your maximum heart rate, as before, but then also takes into account your resting heart rate. I like it because it seems to be a way of taking your existing fitness into account (assuming your existing fitness is loosely marked by your resting heart rate, but I’m OK with making that assumption). The Friel formula is probably the most precise as it is a percentage of your actually Lactate Threshold (the point where you go from exercising aerobically to anaerobically) but unless you have access to a physiology lab you’re going to have to guess your Lactate Threshold. Using the various methods, the upper limit of my Zone 2 is somewhere between 126 and 144 beats per minute. For simplicity sake, I’ve chosen 135 as my number. Could I do better? Maybe, but it is’t the lowest or the highest and it seems to correlate pretty closely to my rating of perceived effort (RPE). For those on a beta blocker medication, which keeps the heat rate artificially slowed, all of the Zone 2 calculations in the world won’t really work. In that case, learn the RPE scale and use it!
Step Two: get a heart rate monitor
None of this really works without a heart rate monitor of some sort, unless you’re just going to go with the RPE scale. If you’re a data nerd like me, you’ll need a heart rate monitor. Most of new Garmins, including the smaller ones, have heart rate monitors built in. The newer Fitbits have HRM (heart rate monitors), the Apple Watch has HRM, and you can even go “old school” and get a chest HRM. If you’re going that route, look at Tickr! a newer chest strap HRM that links by both ANT+ and Bluetooth technology, so it links to most anything (including most newer treadmills) and, oddly, is on sale at Amazon today.
Step Three: slow down!
Go ahead, go do a work out. Go for a run. But as soon as you reach your Zone 2 maximum heart rate, you have to slow down. In fact, you’ll probably have to slow down to a walk until your heart rate comes down. Eventually, you’ll find a pace you can keep for a while, but your heart rate is going to go up again, virtually guaranteed and you’ll have to slow down and walk.
Personal Experience: I was just starting up running after a lengthy time off (infectious mononucleosis) so I know that my aerobic conditioning was off. But, when I started Zone 2 I was back running 4 miles or so at a 9:30–10:00 minute/mile pace and feeling pretty good about it. My first run with Zone 2 I knew would be slow, so I slowed the treadmill down to 5.5 (about 11 minutes/mile). I made it about 10 minutes before I hit my Zone 2 threshold and had to slow down and walk. I spent an hour on the treadmill and managed to just get over 4 miles in, so I averaged about 4.0 for the hour, which is a brisk walking pace. But I’ve varied my workout between running, rowing, stationary cycling and elliptical, all keeping at Zone 2 threshold and within 3 weeks I’m covering 5 miles in the hour. More importantly, I’m running for an hour and feeling really good after. No terrible muscle aches, no cramps and no feelings like I’m physically spent. I anticipate being able to run for the entire 60 minutes soon and then starting the get the pace back up to at least 10 minutes a mile if not better.
OK, you are probably thinking, what a slug. But consider this in a different light. If you could run a 10 minute mile pace in Zone 2 and do a marathon, you’d run the entire race in about 4 and half hours and walk away ready to run the next day. I don’t know many runners who can do that. Imagine, then, what might happen if you did this Zone 2 training not for a couple of months, but a year. Imagine getting to the point that your current “race pace” could be done in Zone 2, so that come race day you could run the first half in Zone 2 and then push yourself a little for the second half. You might walk away with a significant improvement in both your time and your ability to run the next day!
Give up your preconceived notions!
I’ll admit that committing to Zone 2 training is a bit of a leap of faith. But after reading Rich Roll’s account, doing a good bit of research on it and now trying it in my own training, I’m a full fledged convert. So if you think it might be interesting, but know in your heart that you have to run to exhaustion to improve your running capacity, I will ask you to reconsider sometime next year. Because I’m a complete Zone 2 convert and I’m going to run a half-marathon next spring and my firm belief is that: 1) I’ll break my previous PR by at least 5 minutes while 2) feeling better during and after the race than I’ve felt for any previous race. And if I’m right and I’m making serious improvements in my running at age 54 and at least 5 years since I made any other gains, I defy you to come up with a better explanation that just better training through science and understanding.