Arterial adaptations to training among first time marathoners

Abstract

Background: Exercise training favorably alters arterial anatomy in trained limbs, though the simultaneous effects on passively trained arteries are unclear. Thus, brachial (non-trained limb), popliteal (trained limb) and carotid total wall thickness (TWT), wall-to-lumen ratios (W:L), intima-media thickness (IMT) and lumen diameters (LD) were compared between experimental (n = 14) and control (n = 11) participants before and after the experimental participants participated in marathon training. Methods: Arterial dimensions were measured with B-mode ultrasonography. Initial and final testing of VO2max and running speed at 3.5 mmol lactate were measured in the experimental group. Results: VO2max was unchanged by training, but running speed at 3.5 mmol lactate increased by 5 % (p =.008). Time by group interactions were observed for the brachial and popliteal measures (p < 0.05), but not the carotid. No changes were observed in the control group. Prior to the intervention the experimental group had larger LD in the brachial (p =.002) and popliteal arteries (p =.007) than controls; no other pre-testing differences were found. Following training, TWT declined in the brachial (pre =.99 ±.16 mm; post =.84 ±.10 mm; p =.007) and popliteal (pre =.96 ±.09 mm; post =.86 ±.11 mm; p =.005) arteries, characterized by a 0.07 mm decrease in brachial IMT (p =.032) and a non-significant 0.03 mm reduction in popliteal IMT. LD increased in the brachial (pre = 3.38 ±.35 mm; post = 3.57 ±.41 mm; p =.015) and popliteal (pre = 4.73 ±.48 mm; post = 5.11 ±.72 mm; p =.002) arteries. Conclusions: These data suggest that exercise-induced alterations in arterial dimensions occur in trained and non-trained limbs, and that adaptations may be dose dependent.