Complex network model indicates a positive effect of inspiratory muscles pre-activation on performance parameters in a judo match

Abstract

This study investigated the effects of inspiratory muscle pre-activation (IMPA) on the interactions among the technical-tactical, physical, physiological, and psychophysiological parameters in a simulated judo match, based on the centrality metrics by complex network model. Ten male athletes performed 4 experimental sessions. Firstly, anthropometric measurements, maximal inspiratory pressure (MIP) and global strenght of the inspiratory muscles were determined. In the following days, all athletes performed four-minute video-recorded judo matches, under three conditions: without IMPA (CON), after IMPA at 15% (IMPA15), and at 40% (IMPA40) of MIP using an exerciser device. Blood lactate, heart rate and rating of perceived exertion were monitored, and the technical-tactical parameters during the match were related to offensive actions and the time-motion. Based on the complex network, graphs were constructed for each scenario (CON, IMPA15, and IMPA40) to investigate the Degree and Pagerank centrality metrics. IMPA40 increased the connectivity of the physical and technical-tactical parameters in complex network and highlighted the combat frequency and average combat time in top-five ranked nodes. IMPA15 also favoured the interactions among the psychophysiological, physical, and physiological parameters. Our results suggest the positive effects of the IMPA, indicating this strategy to prepare the organism (IMPA15) and to improve performance (IMPA40) in judo match.

Effects of different inspiratory muscle warm-up loads on mechanical, physiological and muscle oxygenation responses during high-intensity running and recovery

“…After 1 h, a dynamic proposal to characterize the strength of the participants’ IM, the global strength index (S-Index), was assessed by an inspiratory threshold (POWERbreathe K5, IMT Technologies Ltd., Birmingham, UK), with the participants in standing position and using a nose clip. Thirty dynamic inspirations resistance-free were performed slowly, with verbal encouragement to inhale a greater air capacity 32 . During the protocol, breathing pattern curves were monitored by graphic records provided by Breathe-link ® software.…”

“…The total protocol was comprised of two sets of 15 inspirations with a 1-min rest interval between them. The loads were equivalent to 15% (WU15), considered placebo by the literature 32 , 35 , 39 , 40% (WU40) and 60% (WU60) of MIP. All experimental trials were randomly distributed.…”

“…Therefore, some studies have focused on IM training, aiming at reducing the IM fatigue in order to maximize performance and oxygenation redistributions 23 – 25 . Moreover, the warm-up or pre-activation of inspiratory muscles (IMW) using a portable device has been suggested to prepare this specific musculature before exercise, and consequently improve the physiological responses during effort 26 – 28 , as well as sports performance 29 – 32 . Positive effects of IMW were observed during high-intensity, short-duration exercises, with increased power in the Wingate test 33 , 34 .…”

“…Different IMW protocols (i.e., number of sets, repetitions and time between sets) and loads (characterized by airflow restriction in the inspiration phase) ranging from 5 to 80% of maximal inspiratory pressure (MIP) have been proposed 29 , 31 , 32 , 38 – 41 . Nonetheless, most studies that applied this strategy used efforts based on individual MIP, generally composed of 2 sets of 30 repetitions at 40% of MIP.…”

“…The application of higher inspiratory loads such as 60–80% of MIP 38 , 39 to improve subsequent results is still controversial and lower loads such as 5–15% of MIP are commonly applied as a placebo condition 27 , 31 , 35 , 36 , 39 . Concerning the number of repetitions, recent investigations have suggested a shorter IMW protocol consisting of 2 sets of 15 inspiratory efforts in order to minimize the time spent during warm-up and improve its application in a sports/physical training environment 32 , 38 , 39 . However, there is a lack of knowledge about the effects of different inspiratory loads of IMW on the mechanical and physiological performance in high-intensity and short-duration running, especially when performing such a short inspiratory protocol.…”