Fast Talk, ep: 73: How to balance your VLamax with Sebastian Weber

In episode 73, we talk about the important balance between our aerobic and glycolytic energy systems and why they may require a little give and take.

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The VeloNews Fast Talk podcast is your source for the best training advice and most compelling insight on what it takes to become a better cyclist. Listen in as VeloNews managing editor Chris Case and our resident physiologist and coach, Trevor Connor, discuss a range of topics, including sport science, training, physiology, technology, nutrition, and more.

Balance. That becomes an increasingly important concept as we get stronger. If you’re unfit, just getting off the couch, everything is trainable. Everything can get better.

But we reach a point where it’s not that simple. We love to look at peak numbers… best 20-minute power, best five-minute power, best top sprint. But can all of these numbers keep rising in unison as we train? The answer is we hit a point where we have to make sacrifices.

Back in episode 67 we talked with Sebastian Webber about the concepts of VO2max and VLamax. Think of them as ways of measuring the max rate of your aerobic system and your anaerobic system (though to be exact we’re talking the glycolytic system only.) A big aerobic engine allows you to do things like sit in the field comfortably for hours or put down a good time trial. In the world of cycling, there’s no such a thing as too big a VO2max. But a big glycolytic system allows you to cover moves and win the sprint at the end of the race.

The problem is that there is such a thing as too big a VLamax because it can hurt your aerobic engine. So it’s a balancing act, and while we love to focus on those peak wattages, an important consideration is to figure out how high or how low a VLamax you need. And that can change through the season.

Today we’ll dive into this concept and talk about:

• VO2max and VLamax – what exactly do they measure and why are they useful
• Another term that’s becoming very popular is W’ or Functional Reserve Capacity. It’s a valuable number, but a lot of cyclists think it’s a measure of our anaerobic strength and confuse it with VLamax. We’ll explain the important differences and the value of both
• We’ll talk about the balancing act of shifting your VLamax depending on your target races
• Then we’ll try to get a little more practical starting with the right training for the time trialer or GC rider
• Next we’ll talk about how to train if, like a lot of riders, you focus on road races and need good enough an aerobic engine to get to the end of a 3 plus hour race, but also need a good enough VLamax to win the sprint
• Finally we’ll talk about just how much you can shift your VLamax and why it’s not just about making that shift, but learning to use what you have.

Our primary guest today is of course Sebastian Weber. Sebastian is one of the founders of INCSYD, a company that uses on-the-road testing to give quite detailed analyses of a rider’s physiology. Weber has also worked with teams like High Road and riders like Peter Sagan and Tony Martin.

I love having Weber on the show because we go deep into the physiological weeds. And also apparently put Chris to sleep. So, I agreed to cut our talk about lactate vs pyruvate transport across the mitochondrial barrier. Don’t ask me why…

Along with Weber we also talked with a pretty incredible group of scientists and riders about this balancing act including Dr Stephen Seiler from the University of Agder in Norway who is one of the originators of the Polarized training model. We have an episode on interval work coming up with him soon.

Next, we got the opinion of a World Class time trialist and Grand Tour rider. Brent Bookwalter who now rides with Mitchelton-Scott, talked with us about how training for time trials and Grand Tours affects his sprint. And if you haven’t done so already, check out his end of season Gran Fondo, the Bookwalter Binge.

And finally, we talked with Dr Andy Coggan and Hunter Allen who just put out the third edition of their groundbreaking book “Training and Racing with a Power Meter.”

So let’s dive into this idea of VLamax and let’s make you fast!

Graph 1: Example 2013 season of how a World Tour rider who is focused on the Spring Classics and a possible sprint win at the Tour de France balanced his anaerobic threshold and VLamax through the season. Notice that he raised and held his threshold through the season, but his VLamax fluctuated.


1. Urhausen, A., et al., Plasma catecholamines during endurance exercise of different intensities as related to the individual anaerobic threshold. Eur J Appl Physiol Occup Physiol, 1994. 69(1): p. 16-20.
2. Messonnier, L.A., et al., Lactate kinetics at the lactate threshold in trained and untrained men. Journal of Applied Physiology, 2013. 114(11): p. 1593-1602.
3. Laursen, P.B., Training for intense exercise performance: high-intensity or high-volume training? Scand J Med Sci Sports, 2010. 20 Suppl 2: p. 1-10.


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