Arterial Stiffness Differences between Aerobically and Resistance Trained Turkish Elite Athletes

The purpose of this study was to evaluate whether arterial stiffness was different in aerobically trained elite athletes than in anaerobically or resistance trained elite athletes. The cohort comprised 36 healthy male volunteers, aged between 17 and 32 years. All subjects were basketball players (n=10), weightlifters (n=11) or sedentary controls (n=15). The Pulse Trace System (Micro Medical Ltd., Rochester, UK) was employed to record central and peripheral arterial stiffness. Echocardiographic images were taken by the use of a commercially available machine (Vivid 7 GE-Vingmed, Horten, Norway) with a 2.5 MHz transducer. Aortic elastic properties derived from echocardiographic measurements did not differ between the groups (p<0.05). Pulse wave velocity measurements reflected significantly lower values in both the basketball players and weightlifters compared to controls (p<0.001-0.05). No significant difference was seen between the basketball players and weightlifters (p<0.05). Contrary to existing knowledge, arterial stiffness of athletes that perform more resistance exercise such as weightlifters improved significantly and did not get worse. This result implies that in the long-term arterial stiffness improves with sports activities that are predominantly comprised of resistance exercises despite increased arterial stiffness in the acute phase. Address for correspondence: Tolga Saka Associate Professor MD Bezmialem Vakif University Medical Faculty Department of Sports Medicine Istanbul, Turkey Telephone: +905333358683 E-mail: [email protected], tsaka@bezmialem. edu.tr INTRODUCTION Arterial pulse wave velocity (PWV) is widely used for the indirect assessment of arterial stiffness. PWV is measured as the transit time of the pressure wave between two remote parts of the arterial tree (Eugene et al. 1982). If the vessel is stiffer, the pulse pressure wave moves faster along the vessel. Regular physical training has a protective effect against cardiovascular diseases such as hypertension, coronary heart diseases, and peripheral arterial occlusive diseases. Although the mechanisms underlying this protective effect probably include favorable changes in blood pressure, plasma lipids and glucose-insulin metabolism (Shephard et al. 1999), an additional possibility is that regular aerobic exercise is associated with enhanced arterial compliance. Accordingly, several studies provide evidence of reductions in central arterial stiffness with en430 TOLGA SAKA, UFUK SEKIR, ALI DOGAN ET AL. durance training in young (Cameron et al. 1994; Kakiyama et al. 2005) and older populations (Collier et al. 2008a; Tanaka et al. 2000), and in competitive endurance athletes (Edwards et al. 2005). Such results were noted from both cross-sectional (Edwards et al. 2005; Vaitkevicius et al. 1993; Kingwell et al. 1995; Monahan et al. 2001) and mostly longitudinal studies (Tanaka et al. 2000; Cameron et al. 1994; Edwards et al. 2004). However, in longitudinal studies exercising durations were between 8 to 12 weeks in general (Ciolac et al. 2010; Ferrier et al. 2001; Madden et al. 2009; Yoshizawa et al. 2009). In few studies the duration of exercise was 26 weeks long (Madden et al. 2013). The effects of the exercise training on arterial stiffness have never been conclusive (Ciolac et al. 2010; Ferrier et al. 2001; Madden et al. 2009; Yoshizawa et al. 2009; Madden et al. 2013). Tanaka et al. (1998) showed that arterial stiffness of the upper and lower limbs in welltrained postmenopausal female runners was not different from that in sedentary counterparts. Hayashi et al. (2005) evaluated the effects of aerobic exercise training on the stiffness of central and peripheral arteries. Following the aerobic exercise training, they found reductions in central arterial stiffness, but no difference in peripheral arterial stiffness. The researchers stated that the stiffness of the peripheral artery was difficult to change in the short-term and moderate-intensity aerobic exercise training. In contrast, Schmidt-Trucksass et al. (2000) indicated that femoral arterial compliance and diameter in endurance-trained males were significantly larger than those in age-matched sedentary counterparts. Today strength training takes up more space in exercise programs. National and international healthcare institutions continue to recommend resistance to be part of physical activity programs designed for both recreational and health purposes (Diabetes Mellitus and Exercise 2000; ACSM Position Stand 1998; Pollock 2000). Resistance exercise is known to strengthen the connective tissue and increase the muscle bone mass (Pollock et al. 2000). Some studies have shown that resistance training benefitted the cardiovascular system although it has not been clearly elucidated in literature. In marked contrast to regular aerobic exercise, it has been shown in longitudinal studies that high-intensity resistance training may increase central arterial stiffness in young (Cortez-Cooper et al. 2005; Miyachi et al. 2004; Okamoto et al. 2006) and middle-aged adults (Collier et al. 2008a). Some cross-sectional comparisons between sedentary and resistance-trained individuals have shown also reduced central arterial stiffening (Bertovic et al. 1999; Miyachi et al. 2003). The possible increased stiffness with both acute (Heffernan et al. 2007a) and chronic resistance exercise (Cortez-Cooper et al. 2005; Miyachi et al. 2004) was restricted to central elastic arteries and not found in peripheral muscular arteries. In contrast, no such changes were observed in several other studies (Casey et al. 2007a; Cortez-Cooper et al. 2008; Rakobowchuk et al. 2005; Yoshizawa et al. 2009). These studies reported contradictory results, that arterial stiffness was not significantly increased after resistance exercise (Rakobowchuk et al. 2005). Rakobowchuk et al. (2005) found that central arterial compliance was unaltered after three months of resistance training in young men. As can be seen, there is no unified view on the effects of resistance training on arterial stiffness and further studies are needed to evaluate the effects of longer duration resistance exercise on arterial stiffness. Therefore, the purpose of this study was to evaluate whether arterial stiffness was different in aerobically trained elite athletes than in anaerobically or resistance trained elite athletes. MATERIAL AND METHODS