Objective: To find the individual intensity for aerobic endurance training, the lactate minimum test (LMT) seems to be a promising method. LMTs described in the literature consist of speed- or work rate-based protocols, but for training prescription in daily practice mostly heart rate is used. The aim of the present study was to investigate the reproducibility of a new heart rate-based LMT protocol.
Design: 20 subjects each underwent 4 LMT’s on a cycle ergometer. The LMT consisted of a first part (Conconi test) to induce lactate accumulation and a second part (incremental protocol) with stages of 5 min starting beyond the aerobic threshold. During these stages work rate was adjusted to reach predetermined heart rates, which were calculated for every single test from heart rate (HR) at rest and maximum HR. Lactate was measured after each stage to define the lactate mini-mum (LM) and the corresponding HR.
Setting: Institute of Sports Medicine
Participants: 20 healthy and endurance trained individuals (13 males, 7 females).
Main Outcome Measures: Reproducibility of heart rate at LM
Results: The reproducibility of heart rate at LM was high (coefficient of variation CV = 2.1%). The reproducibility of work rate at LM was good (CV = 6.7%). CV for lactate concentrations at LM was 17.4%. High inter-individual differences at LM were found in heart rate (range 149–178 bpm) and lactate levels (range 1.2–6.8 mmol•L-1).
Conclusion: The LMT using a heart rate-based protocol is a reproducible method of assessing HR at an exercise intensity where an equilibrium between blood lactate accumulation and elimination exists.