Heart-rate-based prediction of velocity at lactate threshold in ordinary adults

BACKGROUND: Velocity lactate threshold (VLT) is commonly used as a standard for exercise intensity, although previous studies of VLT have focused mostly on well-trained athletes. Heart rate (HR) is an important physiological index which is easy to measure, the heart rate-workload relationship curve is the reported coincidence with lactate threshold (LT). This study aimed to develop valid, simple and economical velocity at lactate threshold prediction methods for general Chinese adults. METHODS: Eighty-four Chinese adults (49 males and 35 females aged 27.1 ± 8.3 years) were recruited to perform a graded exercise test on a treadmill. A 20-s rest time for the blood sample collection was set between each 3-min successive stage. Blood lactate concentration and heart rate (HR) were determined using a blood lactate analyser and HR monitors. Multiple linear regressions were applied to develop VLT prediction models using velocity at different HR levels, genders, BMI and ages as dependent variables. RESULTS: Eight VLT prediction models were established, in which 47%–65% of variance of VLT could be explained. The results of the paired t-tests showed no significant difference can be observed between estimated and measured VLTs. CONCLUSION: In conclusion, simple and convenient VLT prediction models were established, and the models are valid in predicting VLT for general population.