Introduction: Combat sports alternate both anaerobic and aerobic efforts (Smith, 2006). Powerful and fast anaerobic actions are of paramount
importance for explosive punch or kick attacks, feigns and defensive actions. Some authors examined the effects of fight on blood
lactate production among different combat sports (Khanna et al., 2006). However, especially during kickboxing fights, the effects of fatigue
on muscle power and metabolic indexes remain unknown. Therefore, the aim of this research was to determine the effects of
fatigue induced by a kickboxing fight on vertical jump, bench press peak power, heart rate, and blood lactate accumulation.
Methods: Eleven athletes (5 females and 6 males) volunteered for the experiment. Females mean (\ub1 SD) age, height, weight and training
experience were 29.6 \ub1 3.8 yrs, 164.8 \ub1 3.9 cm, 59.0 \ub1 2.4 kg, 6.4 \ub1 1.3 yrs, respectively. Males group was 26.5 \ub1 6.2 yrs, 178.3 \ub1 3.4 cm,
78.3 \ub1 10.5 kg, 8.0 \ub1 1.0 yrs, respectively. Subjects performed unofficial fights with three 120 s rounds with 60 s rest among rounds. Fights
were conducted in accordance with kickboxing rules (low kick style). Athletes, referee, and coaches used their usual competition behavior.
One day before fights, pre-tests were performed to determine bench press peak power using an accelerometer (Myotest, Switzerland),
and vertical jump height during counter movement jumps (Optojump, Microgate, Italy). Just before fights and after warm-up, basal
lactate (Lactate PRO, Japan) was collected. Heart rate (TMpro, Hosand Technologies, Italy) has been continuously recorded during fights.
Finally, immediately after the end of the third round, bench press peak power, vertical jump height, and blood lactate values were evaluated
for post-tests.
Results: At pre-test, a sex effect was found for both bench press peak power and vertical jump height, with males demonstrating greater
values than females (p<0.05). During rounds, heart rate was on average 93 \ub1 1 % of the maximal heart rate. After fights, blood lactate
concentration significantly increased until 13.6 \ub1 2.3 mmol/L (p<0.001). After fights no time effect was found for both bench press peak
power and counter movement jump height.
Discussion: This study highlighted high heart rate and blood lactate values suggesting anaerobic metabolism plays a key role in kickboxing
fights. However, aerobic power also plays an important role during recovery (e.g., lactate clearance). Neuromuscular indexes (vertical
jump height and bench press peak power) were surprisingly unchanged although a fight-induced fatigue. These data could be explained
by the non specific nature of these tests regarding with kickboxing skills