Aerobic and anaerobic capacity of professional soccer players in annual macrocycle

IntroductionSoccer is a demanding sport the performance of which is determined by physical, techno-tactical, psychological, and social parameters. Aerobic capacity is also a crucial factor for soccer success (Ekblom, 1986). Physiological requirements of the game demand a high aerobic and anaerobic capacity, muscle strength, speed, power, skills, coordination and flexibility for the improvement of performance and the injury prevention (Reilly, Howe & Hanchard, 2003). Intensities of the game are also extremely high. Average heart rates have been found to be around 85% of maximal values, and peak heart rates have been close to maximal (Bangsbo, Iaia, & Krustrup, 2007). Furthermore, midfielders cover about 10-12 km with a mean intensity 80-90% of heart rate max and 70-80% of VO2max rates close to the anaerobic threshold (Casajus, 2001; Ekblom, 1986; Helgerud, Engen, Wisloff, & Hoff, 2001; Hoff, Wistoff, Engen, Kemi, & Helgerud, 2002).During an elite soccer game players perform about 1000-1400 repeated movement actions (Bangsbo, 1993; Mohr, Krustrup, & Bangsbo, 2003) with speed and pace changes and several changes of physical demands (Bangsbo & Krustrup, 2008). Soccer players walk about 18-27 min (20-30% of game duration), run on a very low intensity for about 13-23 min (15-25% of game duration), run on a moderate intensity for about 9-13 min (10-15% of game duration), run on a high intensity for about 4-7 min (4-8% of game duration), walking backwards for about 8-12 km (Reilly & Doran, 2001). Aerobic capacity is an important factor that affects the final league ranking, the quality of the game and the covered distances (Hoff, 2005; Impellizzeri, Rampinini, & Marcora, 2005). Furthermore, it may improve performance indicators such as the time spent in high intensity, sprint number, and ball touches during a game. Researchers conclude that high aerobic capacity also improves the recovering of high intensity interval training that alternates with lower intensities during the game (Bangsbo, 1993; Svensson & Drust, 2005). Although aerobic metabolism is highlighted, the most decisive actions such as short distance sprints, jumps, tackling and duals are very crucial for the final result of a game. These 150-250 short but intense actions during a game show that anaerobic capacity plays a crucial role for the final performance (Bangsbo et al., 2007). It is obvious that the quality of high intensity actions develop elite professional players. Specifically, international players significantly differ from professional players as they cover about 28% in high intensity running (2.43 km vs 1.90 km) and 58% more sprints (650 m vs 410 m). Sprints constitute 1-11% of the total covered distance, corresponding to 0.5-3% of the actual play time. During game players perform a sprint every 90 sec that usually lasts for 2-4 sec. Moreover, it has been found that 30 m sprints demand longer recovering period than the usual 10 to 15 m sprints. Thus, sprint resistance and anaerobic capacity are very important indicators of performance. Players are required to cope with these physical demands with the highest physical condition during the whole competitive season (Aziz, Newton, Tan, & Teh, 2006). Therefore continuous assessment, information and feedback regarding physical condition play a crucial role in the success of any team.It is also known that anthropometric characteristics and body composition have a significant effect on performance (Bangsbo, 1993; Reilly, 2003; Reilly, Bangsbo, & Franks, 2000; Shephard 1999; St0len, Chamari, Castagna, & Wistoff, 2005). Because all these parameters change throughout the annual macrocycle many studies examined their changes during a whole competitive period (Mukherjee & Chia, 2010; Ostojic, 2003). In addition, because soccer performance is related with speed resistance the researchers also focused in changes of aerobic capacity throughout a whole competitive period (Aziz, Tan, Teh, & Council, 2005; Caldwell & Peters, 2009; McMillan et al. …