Impact of short-term training camp on arterial stiffness in endurance runners

Lack of elasticity in the central artery causes an increase in left ventricular (LV) afterload. Although regular moderate-intensity endurance exercise improves cardiovascular function, including arterial destiffening, little is known about the effect of short-term vigorous exercise on cardiovascular function (i.e., the interaction between cardiac and arterial functions). We measured arterial stiffness [via pulse wave velocity from the heart to ankle (haPWV)] and LV contractility (via systolic interval time) before and after a 1-week training camp in a total of 33 regularly highly-trained collegiate endurance runners. They participated in three training sessions per day which mainly consisted of long-distance running and sprint training. The averaged running distance was ≈44 % longer during the camp than the regular training program. After the camp, heart rate at rest and haPWV were significantly increased, whereas blood pressure remained unchanged. Although a ratio of pre-ejection period and LV ejection time (PEP/LVET, an index of blunted LV contractility) was unaltered, presumably due to the large variability of individual response, there was a significant correlation between changes in haPWV and PEP/LVET (r = 0.54, P < 0.01). These results suggest that, in regularly highly-trained endurance athletes, arterial stiffness increases after a training camp characterized by greater training volume (vs. regular training), and that the individual response in arterial stiffness correlates with the corresponding changes in myocardial contractility.