# Thread: Interval Training - Anaerobic zone - how do I know when I'm there??

1. ## Interval Training - Anaerobic zone - how do I know when I'm there??

Going into my third summer of cycling, been spinning indoors all winter, feel like I have a good base. Uploaded my Garmin data to Strava, analysis showed that I've done virtually NO work in the anaerobic zone, so I figured time to add interval training to the mix.

I'm 46, so 220-age = max heart rate of 174, so anaerobic zone should be somewhere north of 168 bpm. Today, did first attempt at intervals on bike. Pushing for as hard as I could, as long as I could, legs searing, chest exploding, I found it VERY hard to get my heart rate even past 155, and I only briefly went over 160. Most of the time during the hard intervals I was in the 149-153 range. What does this mean?

2. First, the 220-age calculation is pretty much useless for an individual. It's akin to buying shoes based on your height. The first thing to do is establish what your max heart rate is. You could do a treadmill or training test and just see what is the highest HR you can attain. Or you could do a 20 minute test: go as hard as you can for 20 minutes and use the average HR for that interval as your lactate threshold HR.

I'm sure someone can chime in with a more detailed explanation, but that's it in a nutshell.

3. look at the stickies...there is a 2x20 anerobic test described there

4. Fortunately, I happen to live near a sports clinic that does these sort of tests in a lab enviorment. Maybe its time I made an appointment..

5. There's no such thing as the "anaerobic zone" of the heart rate, it is not a well defined scientific concept. Don't trust Strava on that one. You should be thinking in terms of power output, not heart rates.

Some basics (you might know some of this, but bear with me):

* You have a certain maximum capacity for oxygen intake called VO2max. You can get that measured at a sports clinic if you want.
* When you exercise at a sufficiently low intensity, your power output is proportional to your breathing rate.
* If you try to raise your power output slowly and gradually, you pass through the "lactic threshold" (when lactic acid begins accumulating in your bloodstream), then through the "ventilatory threshold" (when you have to start huffing and puffing), and eventually you can get to VO2max. Everyone's different, but, as a ballpark figure, your lactic threshold is somewhere around 70% of VO2max and your ventilatory threshold is somewhere around 80%. Using this procedure, you can measure your maximum heart rate and your power at VO2max. That is mostly a useless number because it is very difficult to sustain that kind of power output for long. It's easier and less painful to estimate your power at LT/VT and use that as a starting point. The 2x20 test mentioned above should give you a number close to your VT.
* In interval training, the idea is to get your power output close to, or even above VO2max. You can't sustain that power for more than a few minutes, and your heart rate simply may not have time to rise that much. That's exactly what you were seeing in your attempt. Getting the heart rate up is not the point. You work for a few minutes, stop, rest, and repeat. The higher you go, the less time you will last. You can go as high as 200% of VO2max for 30 seconds and 300% of VO2max for 5-10 seconds.

6. Clinic testing can be helpful (assuming they know what they're doing). Better is to establish targets for your thresholds (what eugenek was discussing) and go from there. Besides the stickies here (and I think in the rr forum), there is a bunch of stuff on the web for establishing training zones. Friel wrote the book (actually several) on this and IMO remains a good starting point if you want that amount of detail.

The other factor is what are you trying to accomplish. What kind of riding do you do/want to do and where do you need to improve. Fitness for commuting/touring/hill climbs/century rides/tri time-trial/crit racing can emphasize different things, requiring different training. Although I'm sure none have "establish max heart rate" as a starting point (although a friend who races crits tells me, "if you're not feeling like you are about to die, you're not going hard enough").

7. The other thing that happens is that large training volume will depress HR, sometimes a lot. So your HR at a particular perceived exertion (RPE) will vary with training load. This includes MHR. One needs to be well rested before attempting LTHR or MHR tests.

8. What they said. When doing intervals I will frequently be maxed out in terms of effort but my HR will not have got anywhere near its maximum because of lag. This is much less likely to be the case when I am thoroughly warmed up, however, and by thoroughly I mean having been riding at moderate to high intensity for more than thirty minutes. If I sprint after that degree of preparation, I can send my HR soaring towards its limit.

Ks1g, I recently took up crit racing quite late in life. Your friend is quite right. LOL.

9. Originally Posted by eugenek
There's no such thing as the "anaerobic zone" of the heart rate, it is not a well defined scientific concept. Don't trust Strava on that one. You should be thinking in terms of power output, not heart rates.

Some basics (you might know some of this, but bear with me):

* You have a certain maximum capacity for oxygen intake called VO2max. You can get that measured at a sports clinic if you want.
* When you exercise at a sufficiently low intensity, your power output is proportional to your breathing rate.
* If you try to raise your power output slowly and gradually, you pass through the "lactic threshold" (when lactic acid begins accumulating in your bloodstream), then through the "ventilatory threshold" (when you have to start huffing and puffing), and eventually you can get to VO2max. Everyone's different, but, as a ballpark figure, your lactic threshold is somewhere around 70% of VO2max and your ventilatory threshold is somewhere around 80%. Using this procedure, you can measure your maximum heart rate and your power at VO2max. That is mostly a useless number because it is very difficult to sustain that kind of power output for long. It's easier and less painful to estimate your power at LT/VT and use that as a starting point. The 2x20 test mentioned above should give you a number close to your VT.
* In interval training, the idea is to get your power output close to, or even above VO2max. You can't sustain that power for more than a few minutes, and your heart rate simply may not have time to rise that much. That's exactly what you were seeing in your attempt. Getting the heart rate up is not the point. You work for a few minutes, stop, rest, and repeat. The higher you go, the less time you will last. You can go as high as 200% of VO2max for 30 seconds and 300% of VO2max for 5-10 seconds.

10. Originally Posted by ks1g
Clinic testing can be helpful (assuming they know what they're doing). Better is to establish targets for your thresholds (what eugenek was discussing) and go from there. Besides the stickies here (and I think in the rr forum), there is a bunch of stuff on the web for establishing training zones. Friel wrote the book (actually several) on this and IMO remains a good starting point if you want that amount of detail.

The other factor is what are you trying to accomplish. What kind of riding do you do/want to do and where do you need to improve. Fitness for commuting/touring/hill climbs/century rides/tri time-trial/crit racing can emphasize different things, requiring different training. Although I'm sure none have "establish max heart rate" as a starting point (although a friend who races crits tells me, "if you're not feeling like you are about to die, you're not going hard enough").
I just bought Friel's book. I do the metric century version of the Deer Creek Challenge each year, billed as the toughest century in the US (for the metric, it is 7,000 feet of elevation gain). I seem to get passed by just about everyone, and I mean everyone, on the hills. I want to increase power and hill-climbing ability mainly.

11. Originally Posted by chasm54
What they said. When doing intervals I will frequently be maxed out in terms of effort but my HR will not have got anywhere near its maximum because of lag. This is much less likely to be the case when I am thoroughly warmed up, however, and by thoroughly I mean having been riding at moderate to high intensity for more than thirty minutes. If I sprint after that degree of preparation, I can send my HR soaring towards its limit.

Ks1g, I recently took up crit racing quite late in life. Your friend is quite right. LOL.
I did seem to notice that after I had warmed up well, probably more than 30 minutes into the ride, that the increases and decreases in heart rate as I pushed then recovered seemed to become more uniform in time taken to hit the highs and lows, and in the high and low values. It also seemed like I could hold the high intensity longer after I had been riding for 35 or 45 minutes, and could get the rate higher.

12. Originally Posted by carbonframe
I just bought Friel's book. I do the metric century version of the Deer Creek Challenge each year, billed as the toughest century in the US (for the metric, it is 7,000 feet of elevation gain). I seem to get passed by just about everyone, and I mean everyone, on the hills. I want to increase power and hill-climbing ability mainly.
You don't need to do anaerobic work for that. Building your anaerobic capacity is useful for very short term (30-60S) efforts. It is typically the last system you would train in structured program.

The first thing you should be doing is building a strong base by doing long rides and increasing your weekly hours. This is a good period to drop any excess weight which will have a direct impact on your climbing speed, i.e. a 10% drop in weight will make you 10% faster even if you don't gain any power.

Once you have a good base you can start with threshold intervals starting at 10min and working up to 20-30 min per interval. These are not anaerobic but they will help you with threshold power which is what you need for climbing faster. VO2Max intervals are shorter 3-5min and useful for staying with the group on short, sharp hills.

13. Originally Posted by carbonframe
I did seem to notice that after I had warmed up well, probably more than 30 minutes into the ride, that the increases and decreases in heart rate as I pushed then recovered seemed to become more uniform in time taken to hit the highs and lows, and in the high and low values. It also seemed like I could hold the high intensity longer after I had been riding for 35 or 45 minutes, and could get the rate higher.
That's right. If you ever watch a TT, check out how long a warm-up the riders do.

And listen to what Greg is telling you. The last thing you want is to go anaerobic on a hill, unless it's a very short one!

14. For the scientifically oriented of us, a couple more numbers to go with what I previously wrote. I found one study that reported time to exhaustion near VO2max (unfortunately, for runners rather than cyclists, but it should be applicable): it observed that runners were able to sustain 90% of VO2max for an average of 16 min, 100% of VO2max for 5 min, and 105% of VO2max for 2.5 min.

You can also work backwards from that - if you have a flat road where you can train, work out the speed that you can maintain for 5 min (but not a minute longer), and use that in your intervals.

This is what the heart rate response to intervals (4 min @ 90-95%) looks like for someone with max heart rate of 199 bpm:

hr.png

Source

Once you have a good base you can start with threshold intervals starting at 10min and working up to 20-30 min per interval. These are not anaerobic but they will help you with threshold power which is what you need for climbing faster. VO2Max intervals are shorter 3-5min and useful for staying with the group on short, sharp hills.
Actually, shorter 3-5 min intervals are supposed to be very helpful with threshold power too.

15. Originally Posted by eugenek
Actually, shorter 3-5 min intervals are supposed to be very helpful with threshold power too.
No doubt, but most find VO2Max intervals mentally tougher than threshold work. It doesn't hurt to mix it up a little though.

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