In energy system terms, for all intents and purposes, total power production can be thought of as the composite of 2 systems - the aerobic and anaerobic.

VLamax quantifies the power of the anaerobic (glycolytic) system in producing energy in the same way that VO2max quantifies the power of the aerobic system. Because it is a *power* measurement it is expressed per unit of time, in mmol/L of lactate per second, just as VO2max is expressed in Liters per minute (or ml/kg/min)

Any effort is a composite/balance of these systems. You could have 2 athletes putting out the same power but generating that power in different ways. A good example would be the 1500m on the track. You have some '800m types' with very strong VLamax running just as strongly as '5000m types' coming down a distance with very high VO2max. Obviously, these types of athletes with different physiological strengths will (& should) train quite differently as they are 'getting the job done' in very different ways using a different balance of their energy systems.

This obviously applies strongly to a sport like road cycling where we have 'sprinter types', 'climbing types' and every type in between that must also strike just the right balance in the strength of each system for their specialty while still making it to the finish line!

However, it also applies in a reverse sort of way to a sport like triathlon. If we look at 70.3, for instance, we have some athletes with very high VO2max values coming up from Olympic Distance racing and doing well. We also have other athletes with lower VO2max coming down from Ironman distance racing and doing similarly well. These athletes are able to do so because of the 'weakness' of their VLamax, i.e. they don't use a lot of glycogen & are, therefore, able to maintain a very high % of their VO2max for a long period of time.

Knowing where your own strengths (& weaknesses) lie with respect to each of the systems can provide useful insight into where to direct the training - higher aerobic power or higher/lower glycolytic power

---

Alan Couzens, M.Sc. (Sports Science)
Exercise Physiologist/Coach
Twitter: https://twitter.com/Alan_Couzens
Web: https://alancouzens.com