• Blaz Jereb
  • Vojko Strojnik
Keywords: high-low frequency fatigue, blood lactate, cycling


INTRODUCTION: A comparison among 60 seconds of maximal hopping, dropjumping, and cycling showed the presence of high-frequency fatigue after hopping and drop-jumping and low-frequency fatigue after cycling (Jereb & Strojnik, 1995). It was assumed that a shorter duration of maximal cycling may also produce highfrequency fatigue. METHODS: Nine sport students (age 23.4 + 2.7 years, height 176.9 + 3.3 cm, mass 70.4 + 4.9 kg) gave their formal consent and volunteered for the study. Three Wingate tests were performed: 15 s, 30 s and 45 s test. Fatigue index as a drop in power, blood lactate concentration and tetanus forces at 20 and 100 Hz electrical stimulation for the vastus lateralis muscle were measured. Before all tests and measurements, the subjects warmed-up with the standardized protocol. Measurements were obtained four minutes before and one minute after the workout. RESULTS: Fatigue indexes decreased by 15.5%, 35.77%, and 51.27%, respectively. Blood lactate concentrations were significantly increased after all tests and reached 6.7 ± 0.8 mmol/l, 12.5 ± 1.1 mmol/l, and 12.8 ± 1.7 mmol/l for 15 s, 30 s, and 45 s test, respectively. DISCUSSION: Low-frequency fatigue was dominant after all observed durations of the Wingate test. However, significant differences existed in its magnitude depending on the duration of the test. For practice, this means that the Wingate test is not suitable for highfrequency fatigue assessment. For theory, these results showed that a type of contraction has an important role in the modulation of fatigue appearance. It is possible to assume that during a maximal concentric muscle action low-frequency fatigue will occur, while a maximal stretchshortening cycle exercise may lead to high-frequency fatigue. REFERENCES: Jereb, B., Strojnik, V. (1995). Fatigue Effects of Three Anaerobic Power Tests. Book of Abstracts, XVth Congress of the International Society of Biomechanics, 434-