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Science with STAPS: the anaerobic threshold

Science with STAPS – we explain things!

Individual anaerobic threshold, aerobic threshold, 4 mmol threshold and so on … There probably are many more terms to describe this “mysterious“ threshold so many pieces have been written and lectures been held on. Instead of wasting time defining a name for this threshold, we would rather like to explain what it is all about:Anaerobic threshold in cycling and triathlon FTP

The anaerobic threshold (as we call it) is not the transition from aerobic to anaerobic metabolism. And the allegedly occurring acidification is not the reason for the break-off when riding / running at the anaerobic threshold, either.

The anaerobic threshold determines the highest performance / intensity possible at which physiologically there still is a steady state of lactate. In other words: lactate production (via the anaerobic metabolism) is exactly as high as lactate oxidation (via the aerobic metabolism). Unlike the linearly proceeding lactate oxidation, the lactate production is an exponential process (see picture), therefore both metabolic pathways intersect at a certain intensity. As soon as this intensity is surpassed and by climbs above the anaerobic threshold, the athlete produces more lactate than he or she can break down – with the consequence of acidification.

Clearing up the (wrong!) myths surrounding the anaerobic threshold:

  • the anaerobic threshold is not the transition from aerobic to anaerobic metabolism, but the maximum steady state of lactate, i.e. both metabolic pathways run “equal“, the resulting lactate concentration remains the same!
  • lactate production does not start at the anaerobic threshold only: lactate is always produced (with or without training load!) and further metabolized!
  • acidification is no break-off criterion: where is acidification to stem from when riding at the anaerobic threshold, if lactate production and lactate break down are at equilibrium?!
  • the limitation of stress duration at the anaerobic threshold is of an almost exclusively energetic nature: the consumption of carbohydrates is so high that it cannot be topped up adequately!


Training support in cycling and triathlon by STAPS

Science with STAPS: VLamax – fuel and opponent at the same time!

VO2max is well known, VLamax as well?

VO2max is a term that has been used in endurance sports increasingly often in the past months. Several years ago, only “insiders“ like sport scientists and coaches knew what it meant, meanwhile also ambitious age group athletes employ the term. This is no surprise as it is mentioned increasingly often in articles about pro cyclists. But what does VO2max mean and why is it of such great importance? The term stands for maximum oxygen intake and is considered as the most important criterion of endurance performance.

The situation is different when it comes to VLamax – a parameter that is not yet as well known, but nevertheless just as important. What both have in common is a “V“ that describes the flow rate as well as a “small“max that describes the flow rate’s maximum state. The only, yet considerable, difference between these two parameters therefore is what is transported: the former transports oxygen (O2), the latter lactate (La).

VLamax stands for the maximum rate of production of lactate and provides insight into the anaerobic metabolism of the respective athlete. Explained in a simplified way this means that anaerobic metabolism converts carbohydrates into lactate without the aid of oxygen. Therefore, the rate of production of lactate is not only decisive when it comes to the acidification of the athlete after very intensive exercise load, but also in general in the metabolization of carbohydrates during classical endurance exercise.

Opponent of aerobic performance

Why? Because the one effects the other! VLamax is the “opponent“ of aerobic metabolism (VO2max) and has a positive effect on short intensive loads, but also limits the steady state of the athlete – and therefore also the metabolism.Science with STAPS | Die VLamax - maximale Laktatbildungsrate

Similar to VO2max, performance also may increase with higher VLamax. This, however, does only apply for short, high-intensity exercise like sprints or attacks. If these intensities surpass a short period of time (i.e. several seconds or a few minutes) the excessive production of lactate swiftly leads to a change of blood pH – and thereby to an acidification of the muscles as well as a drop in performance.

As mentioned before, VLamax, however, significantly influences the “classic“ endurance performance. It influences the lactate production and accumulation, the ability to recover and to metabolize fats. A very low VLamax or anaerobic threshold would therefore be of use for a good endurance performance. Also see animation that illustrates how a low VLamax virtually conserves carbohydrates and increasingly uses fats for energy production.

Science with STAPS | Die VLamax - maximale Laktatbildungsrate

The lower the rate the lower the activity of the anaerobic metabolism. For orientation: presumably more than 95% of all endurance athletes are in the area of 0.3 mmol/l/s (production of millimole lactate per liter of blood per second) to 0.9 mmol/l/s.

Triathlon: the lower the better. Cycling: depends on race load

In Triathlon the ideal alignment of the anaerobic metabolism may cautiously be generalized: the lower the maximum rate of production of lactate the better. Even in sprint races the load over a period of time of approx. 20 to 40 minutes (depending on the respective discipline) is high. It becomes even more apparent in long-distance races: a low lactate production saves carbohydrates due to a strong metabolism and allows for riding submaximal loads.

The alignment of VLamax is less clear in cycling: for long-distance rides and high-intensity workouts (cycle marathons, time trials, mountain rides a.s.o.) extremely low rates (<0,35 mmol/l/s) are desirable. If high intensities are necessary at times, e.g. in criteriums, road races or the like – a rate of production of lactate of 0.40 to 0.50 mmol/l/s is recommended. The VLamax of specialist road sprinters or track cyclists mostly is higher, as this sort of energy supply is of great importance with maximum loads. Therefore, no ideal rate of production of lactate can be defined as it depends on the respective competition’s demands.

It is decisive – in cycling as well as in triathlon – to also attach great importance to the maximum rate of production of lactate when determining the endurance performance. The rate of production of lactate is decisive for athletic success and has to be determined individually in order to find out the background of the athlete’s physiology and to include it into the training process!

Further articles of our Science with STAPS series:

Science with STAPS: Optimize your winter training!