Opti cca ts

Following an overnight fast, the subjects visited the laboratory at 7:30 a.m. and rested before the first blood collection. A 22-gauge polyethylene catheter was inserted into an antecubital vein after a 20-min rest, and a baseline blood sample was obtained. A series of blood samples were collected at sets 2, 4, 6, and 8 during interval exercise (blood was drawn at 3–3.5 min during each set). During the post-exercise period, further blood samples were collected at 1, 2, 3, 4, 5, and 10 min after exercise completion. All blood samples used for determining blood gas and electrolyte levels were collected using 2.5-mL syringes containing heparin. A 5-mL syringe was utilized to obtain serum samples.
Blood glucose, lactate, HCO₃⁻, potassium (K+), and sodium (Na+) concentrations; pH; and oxygen (pO₂) and carbon dioxide partial pressure (pCO₂) were measured using an automatic blood-gas analyzer (OPTI CCA TS, Sysmex Co., Hyogo, Japan). These analyses were completed within 15 min after blood collection, and the samples were kept on ice until analysis. Blood glucose and lactate concentrations were measured using a glucose analyzer (FreeStyle, Nipro Co., Osaka, Japan) and a lactate analyzer (Lactate Pro, Arkray Co., Kyoto, Japan) immediately after blood collection.

After overnight fasting, all subjects visited the laboratory at 09:00 and rested for 20 min before blood collection. A polyethylene catheter was inserted into an antecubital vein and a baseline blood sample was obtained. Blood samples were collected before and immediately after completing the HST. Blood samples for determination of blood hemoglobin [Hb] and the hematocrit [Hct] levels were collected using 2.5 mL syringes containing heparin; we calculated changes in plasma volume (PV). The PV was used to correct the plasma variables [29 (link)]. A 10 mL syringe was used to obtain plasma samples that were subjected to 10 min of centrifugation at 4 °C (3000 rpm); all samples were stored at –80 °C prior to analysis. Plasma I-FABP levels were measured in duplicate and averaged using an enzyme-linked immunosorbent assay (ELISA) kit (R&D Systems, USA); the intra-assay coefficient of variation was 2.5%. Blood Hb and Hct levels were measured using an automatic blood-gas analyzer (OPTI CCA TS, Sysmex Co., Japan). All analyses were completed within 15 min after blood collection; all samples were put on ice prior to analysis. The changes in baseline PV after endurance training were calculated using the equation of Dill and Costill [29 (link)]:
where Hct is the hematocrit level and Hb is the hemoglobin level.