Study design: Prospective, experimental study.
Objective: To investigate whether the heart rate (HR) at lactate minimum (LMHR)determined by means of a HR-guided lactate minimum test (LMT) corresponds to the HR at maximal lactate steady state (MLSS) in wheelchair-racing athletes.
Setting: Institute of Sports Medicine.
Methods: Eight well-trained wheelchair-racing athletes (mean age: 33±12 years; height: 169±12 cm; body mass: 59±11 kg; VO(2peak): 2.76±0.73 l min(-1)) completed a HR-guided LMT on a treadmill in their own racing wheelchair. Subsequently, exercise intensity at MLSS and corresponding HR were determined by means of several endurance tests on different days.
Results: All measured parameters (HR, speed, blood lactate, oxygen consumption and rating of perceived exertion) revealed significantly higher values at MLSS compared with values at lactate minimum (LM). However, there were highly significant correlations (r=0.914, P=0.002) between LMHR and HR at MLSS (163±6 versus 172±7 b.p.m.) as well as for speed (r=0.935, P=0.001) and blood lactate (r=0.944, P<0.001) at LM versus MLSS. The correlation for oxygen consumption (r=0.798, P=0.018) at LM versus MLSS was lower yet significant.
Conclusions: There exists a close relationship between LMHR and HR at MLSS in wheelchair racing. This allows the prediction of MLSS based on a single exercise test in this special group of athletes. For practical use during daily training, routine HR at MLSS can be assumed to be 8-9 b.p.m. above the LMHRin wheelchair-racing athletes.