Overtraining Leads To Increased Impulsivity

Sport brings a lot of benefits to our body and mind. Thanks to it, it improves physical fitness, strength and muscle tone, the cardiovascular system and even our cognitive capacity. However, overtraining can also lead to a number of negative consequences.

Among the problems that may have overtraining and without resting enough are addiction to certain sports, such as vigorexia or runnorexia, muscle injuries, heart and respiratory problems, a worsening of the immune system, joint aging and the so-called overtraining syndrome.

Overtraining syndrome

Occasionally, overtraining goes to a higher level leading to overtraining syndrome or staleness . Thus, the syndrome is similar to the burnout that occurs in workers. Therefore, a sharp drop in performance occurs in athletes, even in a state of rest, accompanied by a series of physical and psychological symptoms.

Among its symptoms, it is possible to differentiate between physical and mental overtraining:

Physical overtraining

The physical and physiological symptoms that can appear in this syndrome are:

• Increased blood pressure and heart rate.
• High body temperature
• Hypertension.
• Loss of weight and appetite.
• Gastrointestinal disorders.
• Muscle pains.
• Vulnerability to infections and reduced defenses.
• Increased cortisol.

• Increase in fatty acids.
• Decrease in iron, hemoglobin and / or glycogen.

Mental overtraining

In addition, the following psychological symptoms occur:

• Mood disturbances
• Fatigue and exhaustion.
• Anxiety.
• Irritability.
• Lack of concentration.
• Low self-esteem and confidence.
• Loss of libido
• Sleep disorders.

Additionally, a recent study found that overtraining can lead to increased impulsivity. This fact does not affect this trait in a simple way, but can have very negative consequences on behavior and health.

The study

Last September, a French research group published research on the consequences of overtraining on impulsivity. Specifically, how overtraining affects cognitive control.

To do this, they recruited a total of 37 triathletes, who were divided into two groups: training overload and control group. That is, 19 of them had their training duration increased by 40% in each session for three weeks. The other 19 were supervised in normal training during the same period.

Thus, after the experimental weeks of training (of usual intensity or overloaded) they subjected the participants to an evaluation session. This session was divided as follows:

• For 50 minutes, inside a functional magnetic resonance imaging machine, they carried out cognitive control tasks interspersed with 3 decision making where they had to choose between two financial rewards: one more immediate and the other long-term.

• A 45 minute session of cycling at maximum speed to unleash the effects of overloaded training, seeking fatigue.
• Another 50 minutes in the MRI performing the same cognitive and decision-making tasks as in the first block.

In this way, the researchers observed: the excitability of the cerebral cortex, performance in specific tasks and the preference for immediate or delayed rewards.

What did you find?

The researchers were interested in the activity of the cerebral cortex related to impulsivity, and the results in the task of temporal decisions. The cognitive tasks were included, mainly, to provoke the activation of said brain area.

Thus, comparing brain activity after 45 minutes of acute exercise with activity in the first part of the session, they found a decrease in the activity of the lateral prefrontal cortex during decision making, not in cognitive performance.

This would mean that overtraining has a negative effect on tasks in which a decision must be made on a subjective basis, consuming resources and making the task slow.

In this task, they observed that the overtrained triathletes showed a greater preference for rewards of lesser amount, but earlier in time, compared to the control group and to their own level prior to overload.

Implications

These results are relevant for several aspects. On the one hand, cognitive control, versus impulsivity, helps us to perform tasks in a directed and conscious way. In sport, less cognitive control would lead to a greater sense of security, pushing the body to further limits. In this way, not stopping or resting when necessary or valuing the immediate reward more, could lead the athlete to injuries and riskier behaviors.

On the other hand, that preference for getting the best in the present moment is related to doping. An adulteration of the organism that, in addition to compromising long-term goals, has direct consequences for physical and psychological health.

In summary, as with most activities, accumulated fatigue resulting from overtraining can have negative consequences both in the short and long term. It is important to promote healthy habits, which should include learning to make good decisions and knowing how not to push our body and mind to the limit.