How to avoid blowing up in MTB racing

In 2005, I was the king of blowing up.

In our local mountain bike XC series, top racers from the Trek/VW and Cannondale teams used to show up every week scattered amongst other super fast dudes; I could start with the best of them, but couldn’t finish with them. In our weekly interval training sessions, I was fastest at the start of our 2-minute efforts, but I just couldn’t figure out how to hold on during those last few efforts.

“I just need to get fitter,” I thought. And I was kinda right…except in the wrong way.

Now that I’m a coach, proper pacing strategy is one of the main things I try to teach to my athletes. And we can do this properly when we have power meters.

Back when I was always blowing up, I didn’t have a power meter. I did however have a heart rate monitor, and it was the devil. No one taught me I should ease in to my efforts; rather, to get my heart rate in to my heart rate zone, I’d always start off real hard so that my heart rate would get in to the zone, then I’d settle in to the effort. Races were no different, and my heart rate always looked pretty good. What was I doing wrong?!

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This is a pretty good example of starting too hard and slowing down later. Notice heart rate increase then fading later on.

THE PROBLEM WITH USING HEART RATE

Heart rate is old school, and it’s absolute rubbish of a guide for the beginning of efforts. When we start a hard effort (say from easy pedalling), we recruit more muscle fibers. These fibers can contract for a little bit anaerobically, but eventually need more oxygen which comes about through freshly oxygenated blood and a higher heart rate. For this reason and some other bit, it takes a little while for your heart rate a little bit to catch up. What this means for those training off of heart rate is that often times they are increasing power to greater than what it should be, then reducing power to below what it should be despite maintaining a mostly-even heart rate reading. The feeling in the legs is a bit similar. It’s pretty easy to go hard for a short period of time, especially during a race. It even feels easy for a little while! But soon after the start, it gets hard, and you begin to pay for your early efforts.

RACE STARTS ARE THE DEVIL

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Riders actually start to navigate the trails more efficiently as they repeat laps, which is something I came to understand through in-depth analysis during one of my PhD studies.


The nature of any type of MTB racing gets complicated by single track trails. The perception is that you have to be in to the single track quickly, because you want all the others behind you once you’re there. So at the start of the race, everyone goes HARD. A lot of athletes achieve their PB peak power at the start of a race–this couldn’t be worse for their performance. While this may feel easy at first, and seem like the thing to do, it doesn’t take long to pay for that effort, and payment comes in the form of HAVING TO SLOW DOWN.
Most athletes can produce relatively steady power at a moderate effort for quite a long time, however high power output can only be sustained for a while. In this case, starting hard results in a reduction in power output and is why you are seeing your lap times get slower and slower every lap. This sin’t an ideal strategy if you aim to finish strong! Think about it this way: what is your best 30s power? How do you feel after going all out at that power? Many racers think that just because everyone is going fast at the start of the race that they too have to go hard at the start of the race. This is what I also thought in 2005; I thought I should go all-out to try to stay with Chris Eatough, and try then to hold on to him for another 2 hours… This was stupid. Chris’ critical power was leaps and bounds above mine, and while I could sprint hard to keep up with him at the starts, I had to pay for it…and he didn’t. I didn’t have a power meter then, but if i did the at-home-analysis would have showed me what was going wrong even though my heart rate looked nice and steady the whole race. [Check out Pacing in Enduro for a MTB power analysis]

NEGATIVE SPLITS SHOULD BE YOUR GOAL

Once I got serious about understanding power and how the body responds to MTB, I decided to start as fast as I could, not as fast as the race started. Suddenly, I started getting better results. I can distinctly remember one race at the PA State Championships where I started DEAD LAST; I was literally in last place until the very top of the climb. It felt easy. Then, I started picking guys off. By riding within myself, I rode the descents faster than ever and continued riding the next climb at a pace I knew I could maintain. As other riders fatigued, I passed them. I finished the race on empty, but by riding at a power I knew I could maintain, my lap times got faster from the start to the finish! I finished on the podium!

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When an athlete uploads a file like this, it’s a very proud moment! Look at that finish!

If you’re not pulling negative splits, you are starting too hard. Let me rephrase: if you can’t maintain your starting effort, your starting effort is too hard. If your power numbers are dropping every lap, you are starting too hard. One things we’ve learned in our research is that rider start to become more efficient in how they use their brakes when they repeat laps; this can results in further reduced lap time [more on this when this study is published next month]. Give it a try–what do you have to lose?

KEEP IN MIND:

I realize all types of MTB are dynamic, and that sometimes you have to dig deeper than you want. An example might be going hard to catch on to a group on a road section. In this case you might go hard for a short time but be able to settle back in (but be going faster due to the draft). A general rule of thumb for overall increased speed in humans is to go hard in the places that are slow, and reduce your effort in the places that are fast (you can coast!). Physically speaking, you’ll get more bang for your buck by increasing your power on the climbs than on descents or flats. Also, your fitness might not yet be to the point that you can ride steady for the duration of a race. Maybe try increasing your metabolic efficiency. Those long rides might help.

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When things click **ahhhhh…**

Also, it’s important that if you try starting easier, you make sure to finish having given your all. You’re not starting easier to have a ride in the park–it’s a race after all! It’ll require some practice as there are metabolic limits on your ability to make up time by using a negative split strategy, but don’t bash it until you look at your power and asses your results.

How to try it:

  1. Get a power meter. Spend time understanding what you can do and how long you can do it.
  2. Do a practice race of around 45 minutes long on the same trails on separate days. On one day, go all out as you would normally in a race. On the otehr day, start at a power you can maintain, then aim to go as hard for the remainder of the laps. Compare times. Compare power. Where can you go harder/ Where should you go easier?
  3. Sign up for a race.
  4. Start at the back of the pack.
  5. Be patient, ride smart and finish strong!

Picking a power meter-which should I get??
Pacing when riding down a hill???
Research in MTB is a real thing!
Critical power is probably better than FTP. Try it! 
Get in touch!

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