What is Lactate and How Does it Affect Our Athletic Performance

Article by Dr. Daniel Brotons, Head of the Sports and Health Unit of the Catalan Sports Council and the Sports Medicine Area at ERGODINAMICA Clinic

When we exercise, our body uses energy from what we call aerobic metabolism. This energy is usually sufficient for low to medium intensity activities, such as walking or leisurely biking. However, when the intensity of exercise rises to higher levels, the energy provided by the aerobic pathway is no longer enough to meet the demands of the muscular work we are doing, and a second energy source is activated. This comes from the anaerobic metabolic pathway, providing a quick energy boost in exchange for accumulating lactate.

What is Lactate?

Lactic acid, whose *anion is lactate, is the final product of glucose metabolism or its reserves, glycogen.

It is measured by a micrometric sample of capillary blood, taken with a small puncture in the fingertip or earlobe, and the result is obtained immediately.

Lactate formation occurs at all times during physical exercise, and its concentration varies depending on the intensity of the physical activity we perform.

Lactate in Increasing Intensity Activities

When we engage in increasing intensity sports activities, there is a first phase of pure aerobic endurance. In this phase, fat metabolism is activated before glucose metabolism, and lactate concentration does not increase beyond basal levels.

This involves physical work or exercise utilizing type I muscle fibers, or red fibers, which are primarily involved in endurance work.

In the second phase, the exercise intensity starts to demand more energy, and with the insufficient amount provided by fats, our body also begins to use energy from glucose, thus increasing lactate levels above the basal levels. In this second phase, we reach a new state of stability where lactate has not yet spiked and remains at moderate concentration levels.

Finally, the third phase is when the increasing exercise intensity requires power demands and a high energy supply, necessitating the activation of glucose degradation and therefore greater lactate accumulation. In this phase, lactate concentration exceeds its clearance and there is no longer a state of stability; its increase is exponential. This phase involves the use of type II muscle fibers, which are implicated in speed and power training.

What are the Effects of Lactate?

On one hand, lactate concentration implies the use of a different energy pathway, allowing us to assess the optimization of this energy pathway, which is very important for certain sports disciplines and training intensities. On the other hand, lactate causes metabolic acidosis, physiologically inducing neuromotor blockage. Hence, it is important for athletes to better tolerate this acidity through compensatory buffering mechanisms; otherwise, their performance decreases.

Why is Knowing Our Lactate Levels Important?

With lactate determination, we can precisely identify the first threshold or aerobic threshold (VTh1) and the second threshold or anaerobic threshold (VTh2). Knowing these thresholds, determined by an exercise test conducted by a sports medicine specialist, provides valuable information for making a functional diagnosis of the athlete’s physiological characteristics and allows the athlete or their coach to perfectly plan their training according to established goals.

Additionally, on a nutritional level, lactate determination helps us understand the effort intensities where we activate fat metabolism and glucose metabolism. This information, combined with calorimetric parameters obtained from the exercise test, is fundamental for good nutritional planning.

Currently, a device is being developed to measure lactate levels more easily, continuously, and through sweat, using non-invasive methods. This device is being developed by ONALABS, a company specializing in non-invasive remote biomedical sensor technology for health and sports applications. Studies conducted in hospital settings have shown positive bioequivalence results, and additional tests in sports laboratories, including the validation of the first lactate monitoring prototype during ergometry tests with healthy subjects, have also shown very good results and trends.

With these technological advances, we will be able to obtain physiological information about athletes much more easily, ensuring better training planning, optimizing sports performance, and preventing issues arising from poor training.

Author: Dr. Daniel Brotons

Head of the Sports and Health Unit of the Catalan Sports Council and the Sports Medicine Area at ERGODINAMICA Clinic

*Anion: An ion with a negative charge that comes from a negative element.