Thermographic Evaluation of Lactate Level in Capillary Blood during Post-exercise Recovery

Changes in body temperature and in the blood lactate concentration are typical symptoms of an organism’s reaction to effort. The aim of this work was to search for a relation between the temperature of the lower extremities and the blood lactate concentration. Sixteen non-training male subjects took part in the test (average age: 22.3±1.6 years). They performed maximum-height jumps from a fully knee-bent position for one minute. Their body temperature was measured by thermographic imaging and blood lactate concentration was determined at the beginning and throughout a thirty-minute recovery. An analysis of isotherms showed a strong dependence between the temperature of the front surface (FS) and back surface (BS) of the lower extremities (r=.83, p<.05). Immediately after exercise the temperature of the lower limbs decreased on average by about 1.44°C (p<.001) and then during the recovery period rose almost to the pre-exercise value. There was a significant negative correlation (r=-.29, p<.05) between the temperature of lower limbs and the blood lactate concentration, both for FS (r=-.22, p<.05) and BS (r=-.23, p<.05). The results show that a maximum anaerobic effort is accompanied by a substantial drop of the temperature on surface of engaged muscles and the degree of the drop is proportional to the blood lactate concentration.