But How Do You Know?

A sculler I know, Bill, asked me last week, “How do you know when you are rowing at AT?” along with the usual apologies for asking such a “dumb” question. 

[Here’s a lesson I might decide to live by:  If you feel like you have to apologize for asking a dumb question, you’re probably onto something really deep.]

The answer to this question dovetails nicely with my recent post, “Proxies”, which talks about how to assess level of effort during workouts, but it includes some other useful information as well.  That made me decide to expand my answer to Bill’s question into its own post. 

First, let’s start with a definition.  I’m using “AT” to mean “anaerobic threshold”, and that means something like “the level of effort where the athlete is producing lactic acid at a rate faster than he or she can get rid of it.”  (McNeely, p.30).  This causes lactate to accumulate in your muscles, with the attendant feelings of pain, breathlessness, and wanting to stop.  [I sense that a discussion of lactate and its importance in rowing is an upcoming post.  At some point I should really go back through my old posts where I teased you with all the potential future posts, and actually write them.  Uh, anyone want to donate me a paid working vacation for a week?]

Sometimes AT is abbreviated “AnT” to distinguish it from “aerobic threshold”, which is an easier level of effort, the one at which blood lactate levels just start increasing measurably from their resting levels.  At this level, the vast majority of your muscle fibers are working aerobically; but at higher levels of effort you begin to activate more and more fast-twitch muscle fibers, and they prefer to work anaerobically – thus the increase in lactate levels. 

So why is AT (anaerobic threshold) something to care about at all?  Again, a good question.  The reason is because lactate production is one strong limiting factor on your performance in races that tap your endurance capacity.  This includes 1Ks, 2Ks, head races, and anything longer.  500s, not so much.  And if you’ve ever pulled too hard at the beginning of any race whatsoever and then had to ride out the rest of the race all acidic, you know how excruciating lactate accumulation can be.  [Although some people like that feeling.  Not mentioning names here.] 

Given all of this, a lot of how exercise physiologists have designed training programs has been aimed at increasing an athlete’s power output before reaching the AT.  That ties in with the idea of racing as aerobically as possible, which is a laudable goal both in terms of racing success and in terms of personal comfort. 

Yes, Bill, I know:  I still haven’t gotten around to answering your question.  Bear with me just a little longer, if you will, because I have a little more background to get through. 

When we talk about AT, we’re already talking in physiological terms.  I mention this, Bill, to address your comment, “To say something like 4mmols of lactic acid is meaningless to me - unless somebody is giving me a blood test on the move.”  Quite right, as is your next comment, “I never got the hang of heart monitor pacing.  I could never get my pulse up near what the books and articles say it should be without feeling like I was going to explode.” –Which ties in with the caveats about heart rate monitoring as a proxy for level of effort.  And, as is usual with simple questions, the answer may be more complex than you were hoping for.  But don’t worry, because I’ll give you a few very simple tips at the end.  [What's that funny sound?  It reminds me of a scroll wheel zooming…  --Oh.  Never mind.] 

So:  Okay:  let’s leave out the possibility of on-the-fly lactate testing.  In actuality, lactate testing is done during something like a step test or Test Conconi, which is an unexpectedly challenging workout where you row (or bike, or run, or whatever) at increasingly effortful paces.  Immediately after each interval, which lasts 2’ in a Test Conconi, an athlete’s heart rate or lactate level is measured and graphed against speed or power output.  The end result is supposed to be a graph tracking output and either HR or lactate concentration, and that’s useful to athlete and trainer because it shows what the athlete’s current functional output level is for a particular race pace. 

Regardless of whether you’re doing actual physiological testing, though, it’s important to know where your own AT is.  It’s important in being able to pace yourself and, as Bill found, in being able to do a workout at the proper level.  “Proper” here means, of course, “effective for your own athletic improvement”, rather than “fast enough to be at the front of the coached group.”  [Charlie!  Jamie!]  Bill was asking specifically in reference to a workout I often prescribe because it kicks your ass is very efficient in improving your fitness quickly.  It’s another acquisition from Ed McNeely, so blame him.  This workout alternates periods of time at AT and periods of time just below it, at the Canadian Category V or a vigorous steady state; and it lasts for an hour.  Because you’re oscillating just above and just below that point where you generate more lactic acid than you can process, it spurs your body to generate the enzymes and other physiological adaptations to the increased workload.

There are a few ways of telling when you’re at AT.  One way:  Do a head piece (20’-30’) all out for the distance, at the pace at which you can do the best time over the distance.  Then, either memorize how it feels or note the average speed on your speedcoach, GPS unit, or timer+landmark; or note the range of your heart rate through the workout.  Remember that if you go by feel, your speed will vary as you become more or less fit, but you’ll still be at the right physiological level.  On the other hand, if you go by speed, you’ll have to do another piece every so often as you become more or less fit to find the speed at which you’re at the right level of effort.  If you go by heart rate, you may find that your heart rate rises for the same level of effort if it’s hot out or if you haven’t slept well.  

You can also estimate level of effort on the fly by how much talking you can do during the workout.  During AT work, you should be able to get out a word or two, as if you were bow of a double or 2-seat of a straight four or a quad and needed to give commands, but not more than that.  Breathing is deep and rapid, and at the end of the piece you will experience a newfound appreciation for oxygen.  Finally, for most people, rating is the easiest way to understand this level of effort.  Anything from 24-26 up to 32 is what people race head races at, but I would say that for the purposes of the workout I mentioned a 26 is probably the right range for the AT intervals.  22 is probably about right for the steady state intervals. 

One final piece to remember:  It actually doesn’t matter too much if you’re at a precise split or rating.  You’ll still be near AT, and you’ll still get the benefit from the workout as long as you’re in the general region. 

Happy AT!  And don’t forget to breathe.

Comments

[liz]

Very glad you're back! Love your posts even though I can't say I always remember the details once I'm on the water. So I just keep re-reading them and gleaning more every time. Thanks!