Effect of Kickboxing Fight on vertical jump, muscle power, and metabolic indexes

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 (± SD) age, height, weight and training experience were 29.6 ± 3.8 yrs, 164.8 ± 3.9 cm, 59.0 ± 2.4 kg, 6.4 ± 1.3 yrs, respectively. Males group was 26.5 ± 6.2 yrs, 178.3 ± 3.4 cm, 78.3 ± 10.5 kg, 8.0 ± 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 ± 1 % of the maximal heart rate. After fights, blood lactate concentration significantly increased until 13.6 ± 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.