Acute and delayed biochemical and physiological effects of exhaustive weightlifting exercise

Human Physiology 01/2011; 37(2):200-205. DOI: 10.1134/S0362119711010129

ABSTRACT The goal of the work was a study of the effect of exhaustive weightlifting exercise on prolonged changes in the physiological
and biochemical variables characterizing the functional state of skeletal muscles. An exercise accentuated at muscles of the
hip surface gave rise to a significant increase of the blood lactate concentration, which indicated that aerobic metabolism
was a predominant mechanism of energy supply for muscle contraction. A reduction of the m. rectus femoris EMG amplitude and
frequency, a decrease in the tone of tension, and an increase in the tone of relaxation were found immediately after exercise.
One day later, the amplitude and the frequency of the EMG signal increased. On day 3, the activity of creatine kinase (CK,
a marker of muscle injury) considerably increased, while the amplitude and frequency of EMG decreased. By the ninth day of
recovery, all measured variables with the exception of CK were normalized. A significant negative correlation was found between
the blood serum’s lactate concentration and m. rectus femoris EMG activity at the same time points. Blood serum CK activity
and m. rectus femoris EMG and tone parameters were significantly correlated on the third postexercise day. The data demonstrate
that exhaustive exercise-induced muscle injury resulted in phasic alterations in the electrical activity and the tone of the
muscle apparently related to a decrease in pH because of lactate accumulation in the sarcoplasm and the cascade of reactions
leading to muscle tissue damage.

Keywordsweightlifting exercise–blood serum–lactate–creatine kinase–m. rectus femoris–electromyogram–tone

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