A study of intensity, fatigue and precision in two specific interval trainings in young tennis players: high-intensity interval training versus intermittent interval training

Background The aim of this study is to find the differences between two specific interval exercises. We begin with the hypothesis that the use of microintervals of work and rest allow for greater intensity of play and a reduction in fatigue. Methods Thirteen competition-level male tennis players took part in two interval training exercises comprising nine 2min series, which consisted of hitting the ball with cross-court forehand and backhand shots, behind the service box. One was a high-intensity interval training (HIIT), made up of periods of continuous work lasting 2min, and the other was intermittent interval training (IIT), this time with intermittent 2min intervals, alternating periods of work with rest periods. Average heart rate (HR) and lactate levels were registered in order to observe the physiological intensity of the two exercises, along with the Borg Scale results for perceived exertion and the number of shots and errors in order to determine the intensity achieved and the degree of fatigue throughout the exercise. Results There were no significant differences in the average heart rate, lactate or the Borg Scale. Significant differences were registered, on the other hand, with a greater number of shots in the first two HIIT series (series 1 p>0.009; series 2 p>0.056), but not in the third. The number of errors was significantly lower in all the IIT series (series 1 p<0.035; series 2 p<0.010; series 3 p<0.001). Conclusion Our study suggests that high-intensity intermittent training allows for greater intensity of play in relation to the real time spent on the exercise, reduced fatigue levels and the maintaining of greater precision in specific tennis-related exercises. INTRODUCTION Training for endurance in tennis has, in recent decades, been aimed more specifically at an intermittent and high-intensity workload. At times, high-intensity work is related to anaerobic adaptations, but in recent decades, several studies have been published showing that, with this kind of training, maximum oxygen consumption and the oxidative capacity of muscle fibres are raised through an increase in mitochondria and their enzyme activity. Nevertheless, when the goal is to work more specifically, exercises should have a similar motor structure to the one carried out during a game. The problem, however, is that this can have a negative effect on technical and tactical skill and this is an important and common concern among trainers when choosing specific training systems and exercises. A relationship between fatigue and the deterioration of neuromuscular control in different sports has been established, with loss of motor control and modifications in kinetics and kinematics. 4 In tennis players, fatigue causes a reduction in the intensity of play and shot precision. There have also been findings that show reduced ability to apply strength in processes of excitability and relaxation after 3 hours of play. What are the new findings? " The use of interval training with specific tennisbased actions allows for very high levels of work intensity. " Intermittent interval training that includes exercises regularly used in technical training for tennis allows for very high levels of physiology and intensity of play. " The introduction of rest periods allows for greater precision and the maintaining of motor skills. " We believe that monitoring intensity and skill through the number of shots and errors is a good way to control intensity and motor control in specific resistance training. Su arez Rodrı́guez D, del Valle Soto M. BMJ Open Sport Exerc Med 2017;3:e000250. doi:10.1136/bmjsem-2017-000250 1 Open Access Original article group.bmj.com on January 7, 2018 Published by http://bmjopensem.bmj.com/ Downloaded from