Is Over Training Threshold MetCons Killing Your Performance?

I noticed this recently in my training. I have been flogging threshold work. Lots of 10-15 minute, high sustained effort MetCons. Things like Fight Gone Bad, Helen, 1-mile run + grace + 2k row, etc. Then, one day, I decided I was a little beat up and would just hit a 45′ zone 2 BikeErg. About 20 minutes in, the juices started flowing; I got bored and decided it would be worthwhile to throw a 40-second VO2 Max level sprint at the top of every 5 minutes for the rest of the workout. Oddly enough, my sprint performance was terrible. I felt dead there for 30 watts under my base VO2 max power output and felt so much tension in my entire body.

Some folks will claim that it’s over-training. However, Arthur Lydiard, one of the essential running coaches, was among the first to notice and record a phenomenon: high levels of training at the lactate threshold (i.e., where most MetCons are) hurt one’s aerobic abilities and thus reduce their bodies abilities to clear lactate from the blood.  Yes, that is right; pushing the intensity boundaries can decrease your ability to perform at high intensities.

Why? You ask.

I had lost my ability to clear lactate out of my blood because I had only worked on building my lactate tolerance, not my body’s ability to clear (shuttle) it.

 

Before going further, we need a quick lesson on lactate (referred to by the bro scientist as lactic acid). Lactate is a byproduct of using glucose (blood sugar) for energy. Lactate is vital for muscles to keep working when we are short on oxygen. The problem is that the byproduct of lactate being burned for energy is hydrogen + ions (H+ ions), whose presence chokes our performance and turns our happy blood vessels into a corrosive, acidic soup.

 

Metabolic Conditioning Goals

So, when we train metabolic conditioning, our goal is technically two-fold.

1. We should improve our tolerance for large amounts of lactate (and, by association, H+ ions) by doing MetCons like Jackie and Helen. We should gradually build up our ability to tolerate more lactate.
2. The other thing we do is make our bodies more efficient at clearing lactate out of the blood.

 

My problem in this scenario was that I had not been training aerobic blend workouts. As I mentioned before, CrossFit-style MetCons are all high-intensity, which is a bunch of tolerating more lactate workouts; the reality is we also need to train to clear lactate out of our blood. There are a couple of ways to do that, but my favorite way for CrossFit is through what famous Italian endurance coach Renato Canova calls “blend workouts.” These workouts involve “levels” of intensity. Usually, something at a near threshold pace builds up the lactate in the blood, followed by something slow and easy, followed by a near VO2 max effort, followed by 4-5 minutes of really chill, slow-moving, complex I know, but here is an example of what that may look like:

 

3 Rounds

• 1-mile run @ 5k PR pace (so if your 5k PR is 21:00 you run a 7-minute mile)
• 2 minutes of slow burpees (I will use a metronome set to 10-15 BPM and do a burpee at every click for 2 minutes)
• 1000/800m on the Bike Erg @ Max Effort (going for a PR)
• 200m Farmers Carry @ 53/35lbs, walking at a very easy pace

 

I know it looks daunting, but it’s an enjoyable workout. The only thing in the workout that requires maximum effort is the bike; the rest of the time, it’s pretty sustainable. The best part is that you get good at clearing lactate to the point where you won’t lose your ability to tolerate lactate, as I did in the example above.

If you have made it this far, your head may be spinning slightly. The point of this article is to reiterate something CrossFit teaches at level 1: training at varied intensities. Going as hard as possible is essential, but so is going slow with a few mixed-intensity bouts OR going medium in intervals. If you aren’t doing this, you will leave large holes in your metabolic fitness.

 

I authored all of our Build Your Engine programs because I noticed over my 12 years of coaching that general CrossFit athletes usually only have one gear. They blow up whenever they must do something involving a different gear. I want to help people be prepared for the unknown and unknowable and the means being a complete metabolic athlete. That is what all of these plans do: train your energy systems to be complete, whether it’s tolerating more lactate or clearing it better.