Cardiac vagal index varies according to field position in male elite football players

Abstract

BACKGROUND: Cardiac vagal index (CVI) is supposedly higher in athletes and may differ between sports and/or between field positions. OBJECTIVE: To compare CVI: a) between elite football players vs. non-athletes and b) according to five football positions. METHOD: 242 football players of the first Brazilian/Angolan division were divided in five positions (N): goalkeepers (17), defenders (44), wingers (34), midfielders (87) and forwarders (60) and compared with 303 age-matched healthy non-athletes. CVI was estimated from a 4-second exercise test by quantifying the ratio of two cardiac cycle durations, before and at the end of a fast unloaded cycling exercise. RESULTS: Football players had resting and maximal heart rates of, respectively, 59 and 190 bpm and measured VO 2 max of 62.2 mL/(kg.min). Players and non-athletes showed similar CVI results (median-[P25-P75]) -1.63-[1.46-1.84] vs 1.61-[1.41-1.81] (p = 0.22). Wingers tended to have a higher CVI (1.84-[1.60-1.99]), especially when compared to defenders (1.53-[1.41-1.72] (p = 0.01). There was a modest non-physiologically relevant association between VO 2 max and CVI (r = 0.15). CONCLUSIONS: Football players did not differ from non-athletes in CVI; however, among players, wingers were more often vagotonic, which may represent a hemodynamic advantage for match situations, where rapid heart rate transitions and faster oxygen delivery to muscles are required.

Physiological, morphological characteristics and blood profile of female elite Brazilian soccer players according to position

“…These findings have practical implications for soccer performance, as previous research has indicated that the highest scores in the cardiopulmonary system might be predictive of athletic performance enabling athletes to attack and defend more effectively as likewise as faster recuperation [11,21]. This is important because the endurance capacity of soccer players appears to be related to improvements in the level of play.…”

“…Bishop et al [19] states that a higher VO2max in soccer is an obligatory condition to prolong high-intensity displacements due to the greater contribution of aerobic metabolism to the performance of late sprinters. Position shared by several researchers [11,[20][21] who verify a faster recovery process in those with higher VO2max. Therefore, it can be seen in some studies on international sports teams that this physiological parameter ranged from 45.1 to 55.5 mL/kg/min [16,22].…”