Maximum glycolytic/lactate formation rate (VLamax)

Maximum lactate production rate? What exactly is that and is it related to the maximal oxygen uptake (VO2max)? 

Definition 

The maximum lactate production rate is the ability to produce a maximum amount of energy (ATP) by metabolising carbohydrates in an anaerobic state (without oxygen supply). In this process, a maximum amount of lactate is produced in a short period of time (10 - 15 seconds), which reflects the maximum lactate production rate (VLamax) in millilitres per litre per second (ml/l/sec). 
In our blog about VO2max we have already explained that the VO2max represents the amount of oxygen that our muscles can absorb per minute. Therefore, this function is particularly important for our aerobic energy metabolism. 
VLamax in turn represents the function of anaerobic metabolism. Therefore we can say that VO2max and VLamax - which here represent both types of metabolism (aerobic and anaerobic) - complement each other.

How do I measure my VLamax? 

VLamax must be determined by doing a performance diagnostic. There are various test procedures for this, such as the Wingate Anaerobic Test according to Inbar, Bar-Or and Skinner (1996) (3).
The aim here is to generate a maximum pedal speed (with individually set braking force). The maximum power ("peak power", PP) is usually reached after about 3 - 5 seconds. At the point where the power drops, the body must switch to the glycolytic system (Heck & Schulz, 2002) (5).

According to Mader (1994), a good diagnosis of the lactate production rate is possible with the help of the following formula (4):

Explanation: dLa/dtmax (mmol - l-1 - s-1) = maximum lactate production rate (VLamax) maxNBL (mmol - l-1) = maximum postload lactate  RLa (mmol - l-1) = resting lactate  tbel (s) = loading time  talak(s) = fictive lactate-free time at the beginning of the load

Standard values 0.2 - 0.3 long-distance runner 0,4 – 0,6  0.7 - 1.0 sprinter

Muscle fibre types and their influence on VO2max and VLamax

We have two different muscle fibre types. A distinction is made between slow-twitch (ST) and fast-twitch (FT) muscle fibres. The slow twitch fibres are also called type 1 fibres, or red muscle fibres, while the fast twitch fibres are called type 2 fibres, or white muscle fibres. 
The slow-twitch muscle fibres are well suited for aerobic metabolism and thus for long endurance exercise because of their properties (very many mitochondria). The fast-twitch muscle fibres, on the other hand, are capable of anaerobic metabolism because they contract very quickly and can quickly reach a high output. Because of this, type 2 muscle fibres fatigue faster than type 1 fibres. 
Type 2 fibres are further divided into FTx and FTa fibres. The FTx fibres have significantly more myosin, which means they can contract even faster than the FTa fibres. Compared to the FTx fibres, the FTa fibres have significantly more mitochondria, which makes them somewhat more persistent (1).

It is therefore clear that the VLamax has a great significance for the work of the fast-twitch muscle fibres. The higher the VLamax, the more glycogen the fast-twitch muscle fibres can metabolise and the more lactate is formed. If the VLamax is rather low (<0.5 ml/l/sec), it means that the type 2 fibres are more endurance-oriented and can convert less carbohydrate into energy. In the study "Training Fast Twitch Muscle Fibers: Why and How" by Maglischo (2015) (1) on page 6 - 9 you get a good overview of the characteristics of the different muscle fibre types.

What exactly does this mean for our training? 

As you already know, it is particularly important for endurance athletes to have a well-developed maximal oxygen uptake, so that the muscle cells are supplied with enough oxygen even during prolonged exercise. But what about the maximum lactate production rate? 
The VLamax must always be adapted to your competition profile and should be as low as possible for a long-distance athlete (0.2 - 0.4 ml/l/sec) and significantly higher for a sprinter (approx. 1 ml/l/sec).
It is therefore very important for long-distance athletes to have a low VLamax, as they can then consume fewer carbohydrates and produce more energy via aerobic metabolism. For athletes training for a fast and short distance, it is important to generate power quickly and be able to rely on glycolytic (anaerobic) metabolism.

How do I train my maximum lactate production rate?  

Depending on your training profile, it is therefore important to keep your VLamax low or high.
For most cycling races or triathlons, for example, it is particularly advisable to keep your VLamax as low as possible so that you can draw most of your energy from aerobic metabolism for as long as possible.
It is well documented that training improves the aerobic capacity of FTa fibres so that they fatigue less quickly. The mitochondria within the FTa fibre become larger, more numerous and the number of capillaries surrounding them increases (7). In addition, training increases the lactate buffering capacity of the FTa fibre, which helps to sustain a given power output for longer (1). This adaptation results in the type 2 fibre being less able to contract and perform at a high level less quickly. The Andersen et al. (2005) study also found an increase in FTa and a decrease in FTx muscle fibre content (2). 

At the end: Three practical tips on how to train your type 2 muscle fibres for greater endurance:

1. Strength endurance intervals on hills 
   Everyone knows the classic strength endurance intervals on the mountain. 
   You don't strengthen your muscles, but train your fast-twitch muscle fibres to become more enduring.
   During the power intervals, you pedal at a lower frequency, so you have to use more power to pedal the same distance. This recruits more type 2 muscle fibres, which "learn" to work against high resistance for a longer period of time.

2. Low carb training
   Another possibility is to train low carb. In this case you do not give your muscles, especially the type 2 fibres, exactly what they actually need to work and therefore train them to work differently.

3. Strength training
   Avoid hypertrophy training in strength training.
   We hope you could take something with you in this article! Let us know what other topics you are interested in - maybe you will find something on our blog soon 😉

Sources

1 Maglischo, E. W. (2015). Training Fast Twitch Muscle Fibers: Why and How. Res. Gate, 19, 1-30.

2 Andersen, L.L., J.L. Andersen, S.P. Magnussen, C. Suetta, J.L. Madsen, L.R. Christensen, and P. Asgaard. (2005). Changes in human muscle force-velocity relationship in response to resistance training and subsequent detraining. Journal of Applied Physiology, 99: 87-94.

3 Inbar, O, Bar-Or, O & Skinner, J.S. (1996). The Wingate Anaerobic Test. Human Kinetics, Champaign.

4 Mader,  A. (1994). Energiestoffwechselregulation, Erweiterungen des theoretischen Konzepts und seiner Begründungen – Nachweis der praktischen Nützlichkeit der Simulation des Energiestoffwechsels. In: Mader A, Allmer H: Computersimulation. Möglichkeiten zur Theoriebildung und Ergebnis- interpretation. Brennpunkte der Sportwissenschaft 8: 124-162.

5 Heck, H., & Schulz, H. (2002). Methoden der anaeroben Leistungsdiagnostik. Deutsche Zeitschrift für Sportmedizin, 53(7), 8.

6 Wahl, P., Schütt, S., & Volmary, P. (2016). Power Profiling als leistungsdiagnostisches Tool im Radsport—Identifizierung leistungsrelevanter physiologischer Zubringergrößen. BISp Jahrbuch Forschungsförderung, 17, 63-69.

7 Holloszy, J. (1967). Effects of exercise on mitochondrial oxygen uptake and Respiratory enzyme activity in skeletal muscle. The Journal of Biological Chemistry. 242(9): 2278-2282