Fig. 2

^{©Karsten Königstein}: Study design. The target sample size is n = 39 (n_EC = 13, n_NLPE = 26) and participants will be allocated to their group via a 2:1 randomization model (see section “Power calculation” for details). Expecting a 10% drop-out rate, n = 4 additional participants will be recruited to a final sample size of n = 43 (n_EC = 15, n_NLPE = 28). Abbreviations: baFMD = brachial arterial flow-mediated vasodilation; ECG = electrocardiography; ECs = mature endothelial stem cells; EPCs = endothelial progenitor cells; HDL-cholesterol = high-density lipoprotein cholesterol; LDL-cholesterol = low-density lipoprotein cholesterol; POMS = profile of mood states questionnaire; SVA = static retinal vessel analysis; V̇O2_peak = maximum oxygen capacity