DIURNAL VARIATIONS IN ANAEROBIC CAPACITY BASED ON MAXIMAL BLOOD LACTATE

Abstract

The aim of this study is to assess diurnal variations in anaerobic capacity based on maximal blood lactate levels. Forty-one male participants from the Ege University School of Physical Education and Sports participated in the study. Participants’ chronotypes were determined using the Horne-Ostberg’s Morningness-Eveningness Questionnaire. The 22 morningness-moderate morningness subjects and the 19 eveningness/ moderate eveningness subjects were evaluated in the morning (08:30-10:30 am) and evening hours (5:00-7:00 pm) in terms of resting blood lactate levels, body temperature, resting heart rate, total running time and maximal blood lactate levels. The treadmill protocol to assess maximal blood lactate consisted of running 4x1 min intervals at a pace of 20 km/h on a 6% incline. Blood lactate was monitored at the 3rd, 5th and 7th minutes to establish its maximal levels. In the morning hours, body temperature, resting blood lactate and maximal blood lactate were respectively measured as 36.5°C (36.3°C-36.8°C), 1.55 ± 0.41 mM and 15.11 ± 1.57 mM. The same variables were measured as 36.7°C (36.6°C-36.9°C), 1.81 ± 0.51 mM and 15.90 ± 1.85 mM in the evening hours. Resting blood lactate (p<0.05), body temperature (p<0.05) and maximal blood lactate (p<0.001) were found to display significant diurnal variation. It may be accordingly concluded that maximal blood lactate, thus anaerobic capacity have diurnal variation characteristics. Therefore, this situation should be considered when designing anaerobic power and anaerobic capacity type trainings.