Talk test: a simple alternative to identify lactate thresholds during progressive cycling exercise

The assessment of speech production difficulty has been used to control aerobic exercise intensity through the Talk Test method. The aim of this study was to compare the Talk Test variables to lactate thresholds using an incremental test. Thirteen male subjects performed an incremental cycle test to identify the first lactate threshold (LT1), second lactate threshold (LT2) and transition points of the Talk Test. During the incremental exercise test subjects read aloud a standard paragraph at the end of each stage. The last stage at which the subjects could talk comfortably, the first stage at which the subjects could not talk comfortably, and the first stage at which they definitely could not talk comfortably were referred to as the last positive (LP), equivocal (EQ) and negative stages (NEG), respectively. The power output (88±22W) and heart rate at the first lactate threshold (115±15 bpm) were significantly lower (p<.05) than the power output at the last positive (127±26 W) and heart rate (131+21 bpm) at the last positive. The power output and heart rate at the second lactate threshold (169.5 ± 22.6 W; 157 ± 14 bpm) were not significantly different (p=.195) from power output and heart rate at the equivocal (178.8± 30.3 W; 161 ± 15 bpm). The heart rate at the second lactate threshold and equivocal were significantly correlated (r=.57; p<.05). In conclusion, this study showed that the equivocal stage of the Talk Test can be used as a simple tool to indirectly identify the second lactate threshold in healthy men during cycling exercise. Keys words: exercise test, speech production, physiological thresholds