Lactic acid in the muscles

Many believe that acetylsalicylic acid can counteract the accumulation of lactic acid from intense activity. In fact, this belief is incorrect.

Among athletes and fitness enthusiasts there is an insistent rumour: acetylsalicylic acid (ASA) would be enough to counteract the accumulation of lactic acid that follows intense muscle activity. In fact, it has long been shown that taking the analgesic does not limit its production at all.

So why do so many athletes feel relief from taking Asa after intense exercise? The answer seems to lie in the anti-inflammatory and pain-relieving properties of the drug. Often, in fact, muscle pain is associated with trauma, injury or excessive tension that can be relieved by the analgesic. In addition, acetylsalicylic acid effectively protects against oxidative stress generated during muscular effort. Nothing to do, however, with the accumulation of lactic acid.

But how is lactic acid formed, and why? Let’s see in detail the characteristics.

Lactic acid, also called lactate, is a substance produced by cells present in the body, even in resting conditions, as a result of a chemical reaction and serves to generate energy. If in excess, however, lactic acid becomes harmful because, as a result of a synthesis higher than that which occurs under normal conditions, it accumulates in the muscles and produces toxins that negatively affect the efficiency of the muscular system, causing pain, cramps and the appearance of muscle fatigue.

It is a physiological process; in the pathological field, however, a hyper-production of lactic acid can also occur in the case of alcoholism or eating disorders, or serious diseases such as tumors, AIDS, liver disease.

When the effort is excessive

A small amount of lactic acid is always present in the muscle after physical activity: it is what is called a natural waste of muscle contraction. Its formation occurs when muscular effort occurs in the absence of oxygen, as can happen in the case of intense and / or prolonged physical exercise.

Lactic acid therefore derives from sports practice as a consequence of anaerobic muscle activity, and will be greater the lower the individual’s level of training.

Lactic acid production and athletic condition are in fact linked by an opposite relationship: the less a person is used to performing intense physical exercise, the greater the amount of lactic acid produced and accumulated in the muscles. The appearance of burning and muscle fatigue is a sign that the rate of lactic acid production is higher than that of disposal. This makes further effort impossible.

In these situations, lactic acid accumulates at the level of the muscles which, however, do not use it in any way; Initially, therefore, it forms deposits on the cellular and tissue plane. This molecule is then transported by the blood to the inactive heart, liver and muscles, which transform it into glucose: in this way its natural degradation takes place, of variable duration depending on the quantity to be disposed of.

If, however, the level of lactic acid that pours into the blood is higher than the amount that the body is able to dispose of, its excess causes a burning sensation in the muscles accompanied by fatigue. This phenomenon usually occurs the day after training, and tends to disappear shortly after.

The anaerobic threshold

To better understand the mechanism of lactic acid accumulation it is necessary to define the concept of anaerobic threshold. This term indicates the moment at which, during a training session, the anaerobic lactic acid metabolism begins to be more active than the aerobic one.

This threshold indicates the maximum intensity of physical exercise that allows not to accumulate lactic acid: below this value the concentration of lactic acid in the blood remains constant and therefore the body is able to dispose of it with the same speed with which it is produced (the aerobic system prevails).

When, on the other hand, the basic physical effort is more intense and prolonged, especially during resistance exercises, and there has not been adequate preparation in the form of stretching or warm-up, lactic acid begins to accumulate and the anaerobic lactacid system is activated, as aerobic metabolism is not sufficient to guarantee the energy supply required by that type of activity.

It should be noted that these two energy systems, and a third, the anaerobic alactacid system (which does not cause accumulation of lactic acid) are always simultaneously active and, all together but to different degrees, contribute to energy production. Since they are the result of a balance between power (amount of energy produced in a unit of time) and capacity (total amount of energy that can be produced), depending on the various stages of training and the intensity of the exercise one or the other will prevail.

But how is the value of the anaerobic threshold measured? One parameter used is heart rate: usually the threshold corresponds to a value equal to 80-90% of the maximum heart rate.

The threshold then depends on the degree of training. A trained person can perform high-intensity exercise without having lactic acid accumulation, and even reach 85% percent of their maximum heart rate. In sedentary individuals, on the contrary, the anaerobic threshold is much lower and lactic acid can begin to accumulate as early as 55-60% of the maximum heart rate.

With regular and intense training programs it is possible to increase one’s threshold value, and therefore also increase the level of lactic acid that the body is able to metabolize. In this way it will be possible to carry out a more prolonged sports performance over time without suffering from the negative effects of the accumulation of lactic acid.

How is lactic acid disposed of?

Lactic acid is disposed of quickly through normal metabolic mechanisms. This process can take from a few minutes to a couple of hours, but the amount present in the body halves every half hour or so, so its reduction is relatively rapid, and the pain should disappear soon once the period of the individual workouts is over.

When the metabolism falls below the anaerobic threshold, the body converts it back into water and carbon dioxide, respectively expelled through urine and respiration. A share of about 20% is converted back into glycogen so that it can be reused as a source of energy by muscle cells.

For this reason, delayed onset muscle soreness does not depend on the accumulation of lactic acid, i.e. 12-72 hours after exercise and can last for 5-6 days.

The discomfort in these cases is to be attributed to micro-muscle injuries or posture errors, which trigger painful inflammatory mechanisms and processes. Microlesions tend to heal in a short time, while for postural problems specific exercises are needed, for which it is good to contact specialists.

Remedies to eliminate lactic acid

Obviously, you can follow some very simple practical tips to reduce the excessive accumulation of lactic acid during sport in complete safety, intervening comprehensively on the factors that cause it and that prevent its elimination.

First of all, to promote the disposal of lactic acid and recover muscle efficiency, it is important to take care of the post-workout phase. Suspending it altogether is not a good idea; Rather than total rest, it is better to dedicate yourself to active recovery, that is, to a milder physical activity and a muscle cool-down phase. In this way, it is possible to actively prevent the accumulation of lactic acid and, consequently, its most harmful effects on the body.

In this regard, stretching exercises are useful to stretch the muscle fibers, as long as they are carried out correctly, with a moderate rhythm and, if possible, under the guidance of an expert since they could otherwise worsen the condition. Stretching even before training can help reduce the discomfort of lactic acid accumulation.

A remedy to relieve pain after exertion and reduce excess lactic acid are massages. For competitive athletes, massages are part of the training program, and can also be performed by muscle electrostimulation. But even amateur athletes can resort to it, perhaps self-practicing them: lightly massaging the painful part generates a localized heat in the area affected by the accumulation of lactic acid and promotes its disposal.

When the massage takes place through the water, the results are even better. The hydromassage, thanks to the physical properties of the liquid, exerts a gentle and effective action on muscle fatigue and can be associated with sauna and Turkish bath sessions. Here, too, the action of heat on circulation helps the elimination of lactic acid, as well as producing several proven beneficial effects on health.

It must be said that those suffering from heart disease or blood pressure disorders, children and the elderly should not practice sauna and / or Turkish bath without first seeking medical advice. Even without having a spa, a hot bath at home can be very positive for the well-being of the muscles.

The use of sodium bicarbonate, in the right doses, for its alkalizing action can counteract the formation of lactic acid. Studies on athletes have shown that drinking a solution of water and baking soda before a race can improve performance. However, do not exceed the dose of 0.3 grams per kilogram of body weight; In fact, excess bicarbonate can cause gastrointestinal effects such as nausea, vomiting, diarrhea.

It is also possible to reduce the effects of lactic acid through food. Mineral salts such as magnesium and potassium are important for muscle functioning, nerve impulse conduction and muscle contraction. They are foods such as rich fruits, bananas, green leafy vegetables, legumes, whole grains, cocoa and dried fruits.

More oxygen, training and rest

To eliminate excess lactic acid, simply give the muscles a little relaxation to let them reoxygenate. If the amount of oxygen is insufficient, in fact, lactic acid is eliminated much more slowly.

As soon as the blood is again able to transport it out of the muscles, the lactic acid will be disposed of within a few minutes or at most in a couple of hours. And the oxygen that will reach the muscles will allow the resumption of the so-called aerobic effort, without more soreness or burning.

In other words, the easiest way to reduce lactic acid formation is to limit the situations that cause it to accumulate, performing low-intensity exercise.

But also an appropriate training, which improves tissue oxygenation and the efficiency of aerobic metabolism, increasing the threshold beyond which the accumulation of lactic acid in the muscles begins.

In addition, to avoid pain from excessive effort, which often require the intake of an anti-inflammatory analgesic, it is good to associate the activity of warming, cooling down and stretching. On this point it is also useful to follow every indication of the experts, from your doctor to a qualified personal trainer, so as to reduce any risk associated with these activities.

Finally, drinking properly before, during and after exercise is very important, because, by balancing the water losses associated with sweating, it allows the blood to maintain intact the ability to transport nutrients and oxygen to the muscles under stress.