The Importance of Lactate.

See, TC?  I’m making good on a promise to discuss an issue I referred to.  –And that check will be arriving soon, yes? 

Also, people interested in training by splits may want to look back at a comment to the original post on the topic, because reader Joy asks how to calculate the splits.  I've replied to her comment with that information, and can give folks some information on how to construct workout plans for yourself if you don't have a coach to do it for you.  But now, on to today's topic:  Lactate. 

 

In the throes of acidosis, I’ve often wished – prayed – begged – that we could race without incurring all the pain of lactate production.  And, of course, realized how futile that wish is.  In any case, it might be useful to look a little at why lactate is important in rowing, and when it might or might not actually help you. 

 

First, I feel it’s necessary to clear up an issue that I might have misled you on (well, me and practically everyone else who writes about aerobic or anaerobic thresholds).  When we use terms like “anaerobic threshold”, that implies that your body doesn’t begin producing energy anaerobically (i.e., producing lactate) until you reach a certain level of output.  But of course that’s not true.  You’re producing lactate all the time.  It’s just that, when the energy demands on your body get to a certain point, you need to produce proportionally more of your energy anaerobically.  Keep that up and it’ll eventually result in your reaching a point where you can just barely keep up with processing the amount of lactate you’re making, and that’s your anaerobic threshold.  Ernest Maglischo, author of my favorite book on exercise physiology, says on page 343, “A more accurate term is the respiratory anaerobic threshold, or simply the respiratory threshold.”  [This book has 791 pages, just so you know.]

 

It’s also going to be useful to understand the three stages of energy metabolism.  They are: aerobic metabolism, anaerobic metabolism, and the ATP-CP system.  Without going into too much detail here and distracting from the topic at hand, the aerobic metabolism functions to derive energy from aerobic glycolysis, changing muscle glycogen to glucose, then to pyruvate and hydrogen ions, and finally to carbon dioxide and water.  While aerobic glycolysis is much more efficient than the anaerobic phase of glycolysis, in that it allows much more energy to be released (something like 13 times more energy), it also takes about twice as long. 

 

On the other end of the energy spectrum is the ATP-CP system, also called the “anaerobic alactic system.”  That’s because is does not use oxygen to produce energy, nor does it produce lactate.  In this metabolic process, ATP is recycled (and energy produced) by breaking down CP, or creatine phosphate.  This process releases energy very quickly, allowing muscle fibers to contract at maximum speed, but only for about 5 seconds.  The CP supply within muscles declines quickly enough that by the end of the first 20 seconds or so of exercise, the contribution of this system to energy supply is pretty much nil for most races. 

 

So, from about 5 or 10 seconds into a race until the end, you’re getting most of your energy from glycolysis (breaking down glycogen).  The anaerobic phase is actually the first part of glycolysis, and you can continue metabolizing the byproducts of this phase aerobically into CO₂ and H₂O if the energy demands on your body are not too great.  The rate of anaerobic glycolysis, on the other hand, is limited by the amount of certain enzymes that are used to catalyze the reactions, but that amount can be increased with training – sprint training.  Acidosis is actually caused by a buildup of hydrogen ions, which lowers the pH in your muscles, and causes not only pain but a loss of muscular power and speed.  And even though you might will yourself to work through the pain, pain tolerance alone won’t help you overcome the reduction in speed from acidosis.  If you keep going, you get stiff, then numb, and once I even felt a kind of interesting "sparkling" feeling just as my muscles sort of ground to a halt. 

 

So why’s it good? 

 

There are several reasons. 

 

One is that when you start getting acidic, it can mean you’re pulling hard enough to achieve the benefit the exercise is designed to proffer.  Getting acidic can also mean you’re pulling too hard, especially if what you’re trying to train is the aerobic glycolitic energy system.  

 

Engaging in anaerobic glycolysis enables you to perform at speeds that are higher than you could if you stayed completely aerobic.  You know that already – if you don’t pull hard enough, sure, it doesn’t hurt; but you also get beat real quick. 

 

In a larger sense, there are substantial advantages to lactate-production training.  You do this to improve sprint speed (and, remember, as rowers we sprint at the beginning of some races, as well as at the end – but don’t get me started on that topic.  Yet.)  You also do it to increase your body’s ability to buffer lactic acid, because eliminating it won’t completely do the job. 

 

Improving sprint speed involves, in turn, two parts.  One part is developing the ability of your muscles to produce large amounts of force very quickly, using the anaerobic system; that is, developing anaerobic power.  The Canadian rowing trainers (that’s a way for me to say “Ed McNeely” without sounding like a sycophant, though that’s kind of what I am) have a “Peak Power” workout that they use with rowers and scullers for just this purpose.  The idea is that increasing the peak power your muscles can produce during rowing, you’ll also improve your submaximal power output.

 

Improving sprint speed also involves increasing your anaerobic endurance, which is the largest percentage of maximum (anaerobic) power that you can maintain for the length of a race.  For most rowers and scullers, races fall into the “middle distance” category, which means that half  to three-quarters of your energy during racing comes from aerobic sources (depending on the length in time of the race, not just on the distance of the race).  For this reason, middle- and longer-distance athletes need to work more on oxygen consumption and lactate removal more than lactate buffering.  To that end you will add to your aerobic and peak power workouts what Maglischo calls “Lactate Production training.” 

 

Even though there is a lot of truth to the idea that training to produce lactate is antithetical to training to remove lactate, in fact both are important.  Training to improve the ability to produce lactate very quickly is a way of bumping up your sprint speed, and then taking lactate away quickly allows you to keep up that high rate of speed longer.  But when you do lots of basic aerobic endurance training, the contraction speed of your fast-twitch muscle fibers, the ones that like to be anaerobic, will decrease.  So you can train the fast-twitch muscles even without affecting the slow-twitch muscles (because basic endurance does the reverse). 

 

During peak power workouts, you want to give yourself a lot of rest.  You also want to avoid a lot of pain from acidosis.  Why?  Because you want to build it up fast and get rid of it fast.  You don’t want to incur a lot of acidosis, since this actually slows the rate of anaerobic metabolism.  It turns the workout more into a buffering one or a pain-tolerance one.  And those are important, but in smaller quantity. 

 

At the beginning of your workout three to five mornings per week, take a very easy warmup (like what you would do for lifting).  [TC, you’ve just reminded me that the topic of lifting for rowing is a very important one and that I should cover it at some point.  So there.]  Then, do the following:

         10x [10 seconds on, 1 minute off]

Your 10 seconds on will be absolutely all out, as hard and fast as you can go, for about 3 strokes at most.  It doesn’t really hurt, because you mostly use the alactic anaerobic energy system.  Then you paddle really, really easy for a minute, or even longer if you want.  Do that ten times, then do your regular workout for that day. 

 

To progressively overload yourself throughout the training season, you can increase the speed at which you do sprint pieces as the season progresses.  Increasing the volume (doing more of them) is also a good way of pushing yourself with this work.  But don’t decrease the rest between the pieces.  If you do, then you’ll just cause acidosis to occur sooner, and you will reduce the pieces’ effectiveness.  You want to rest enough that you can pull at the same speed through all the pieces; if your speed suffers, you’re done with the workout and it’s best to move to something else. 

 

Does this answer or raise questions?  Let me know.  First time I’ve written about this, so I expect I can do a better job with practice.  But let me know.