CD28 and hereditary elliptocytosis: After the 6 week intervention, HIIT increased the percentage of CD28+ (%CD28+) lymphocytes (Fig. 2B, P < 0.05) and decreased the %CD57+ lymphocytes (Fig. 2E, P < 0.05) at rest and after HE, whereas MICT only increased the %CD28+ lymphocytes (Fig. 2B, P < 0.05) and decreased the %CD57+ lymphocytes (Fig. 2E, P < 0.05) at rest.