Abstract

Anaerobic Sport events, e.g. Cricket, make use of mostly carbohydrate metabolism, which in turn is the main producer of lactic acid. This results in lactic acid concentrations exceeding the normal threshold value and reaching values near 8mmol/L. Aerobic fitness, e.g. endurance athletes, makes use mostly of fat metabolism, thereby producing lower lactic acid concentrations. This study was designed to determine whether or not the lactate threshold occurred at 4mmol/L, and if an individual anaerobic threshold (IAT) could be proposed? A direct running VO2 max using the MedGraphics cardiopulmonary exercise testing system was done on thirty-six endurance athletes with an average age of 36 years. The MedGraphics cardiopulmonary exercise testing system provides computerized gas exchange date for each individual breath and 12-lead ECG information regarding heart rate. The running protocol was done on a Quinton treadmill and consisted of different progressive incremental stages were the elevation was kept constant at a 1% grade, while the running speed was increased. The results showed that more than 90% of the athletes would have over trained if training was dictated by the 4mmol/L intensity. In conclusion the evidence presented questioned the reliability of a lactate threshold. The authors are of the opinion that blood lactate concentrations cannot be used as a measure for prescribing the highest work intensity when training without fatigue. An individual anaerobic threshold can be proposed due to individual variability in athletes. Training an athlete at his/her own individual anaerobic threshold would lead to increased aerobic fitness and performance without placing unnecessary stress on the body. Verf.-Referat