The Acute Effects of High Intensity Interval Training on Circulating EPCs and VEGF in Trained Swimmers

• Main Authors: Lee, Ling-Chun, 李凌純
• Other Authors: Chiang, Jasson
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/00862837516007356653

博士 === 中國文化大學 === 體育學系運動教練碩博士班 === 102 === Endothelial progenitor cells (EPCs), originated from bone marrow, have the ability to proliferate, mobilize, and differentiate into endothelial cells. EPCs can repair damaged endothelium and have angiogenic and vasculogenic potential; therefore, they play an important role in maintaining vascular health. Exercise has been shown to increase EPCs numbers and to induce mobilization of EPCs from the bone marrow as well as increase their angiogenic capacity. High intensity interval training (HIIT) has been proven to be fast and effectively improves athletic performance; however, it may also have some adverse effects. The homeostasis of healthy endothelial function may depend on the balance between the rate of damage and the ability to repair in endothelial cells. In the past, limited researches had examined the effects of exercise on EPCs in trained athletes, and mostly on land exercise. Swimming is a sport that utilized vast amount of interval training, the effect of interval training on EPCs has never been investigated. Due to lack of available data, this study aims at investigate (1) the effect of single bout of high intensity interval swimming exercise on acute immune responses in well-trained swimmer (EPCs, CECs, apoptotic CECs, VEGF, IL-6, TNF-α, Creatinine, ALT) (2)the relationship among the above immune parameters in high intensity interval swimming exercise. 15 well- trained competitive swimmers participated in this study. Subjects swan 20 repeats of 100m freestyle at 105% critical velocity with work/rest ratio equaled to 3:1. Blood were drawn before and immediately at 0mins, 30mins after exercise, and the following immune responses were assessed: EPCs, CECs, apoptotic CECs, VEGF, IL-6, TNF-α, Creatinine and ALT. Statistical analysis: one-way repeated measures ANOVA for the within subject comparisons or nonparametric Friedman test were used if appropriate. Also, Pearson’s correlation or Spearman's rank correlation was used to exam the relationships among above parameters when appropriate. The results of this study show that a single bout of HIIT swimming exercise can significantly increase EPCs numbers (Friedman test: before exercise 5, 0mins after exercise 4, and 30mins after exercise 11 counts/100000 cells, χ2(2) = 25.200, P < 0.001). EPCs at 30mins after exercise increased almost 2.65 folds than that of before exercise. The CECs considered being a marker of endothelial damage increased 30mins after exercise (Friedman test: before exercise 45, 0mins after exercise 31, and 30mins after exercise 66 counts/100000cells, χ2(2) = 20.933, P < 0.001).; the increment was about 1.854 folds than that of before exercise. VEGF seems to be the factor to mobilized EPCs, VEGF increased immediately after exercise (before exercise 44.65 ±11.76, 0mins after exercise 61.38±13.83, and 30mins after exercise 47.32 ±10.37 pg/ml, F(2) = 11.214, P < 0.001) and was positively correlated with the number of EPCs at 30mins after exercise(r=0.756, P<0.01). Serum ALT significantly increased at the peak immediately after exercise then recovered after 30mins (Friedman test: before exercise 12, 0mins after exercise 19, and 30mins after exercise 14 U/L, χ2(2) = 21.926, P < 0.001). Serum Creatinine significantly increased at the peak immediately after exercise and maintain elevated 30mins after exercise (Friedman test: before exercise 0.8, 0mins after exercise 1.2, and 30mins after exercise 1.0 mg/dl, χ2(2) =27.193, P < 0.001). Although Creatinine and ALT elevated after exercise, but the magnitude had not exceed normal range indicated that no serious damage cause by exercise. Similar to the results of previous researches, the IL6 escalated in an exponential fashion and reached 6.75 folds at 30mins after exercise (Friedman test: before exercise .37, 0mins after exercise 1.69, and 30mins after exercise 2.64 pg/ml, χ2(2) =30.000, P < 0.001). The TNFα increased after exercise and maintain elevated 30mins after exercise(before exercise .94 ±.15, 0mins after exercise 1.29±.13, and 30mins after exercise 1.09 ±.14 pg/ml, F(2) = 60.266, P < 0.001), which indicated exercise cause slight pro-inflammatory immune response. The CECs outnumbered EPCs after exercise which indicated a single bout of high intensity interval swimming exercise induce damage exceed repair capacity, which may have adverse effects on endothelium. However, other researches results show EPCs numbers peaked at 24~48hrs after exercise; therefore, future study can extend duration of observation and compare ratio between EPCs/CECs in different mode of HIIT for finding an effective training mode that without the adverse effects.