The comparison of endothelial function of moderate intensity interval exercise with continuous exercise in healthy men.

Background/aim: Exercise enhances endothelium-dependent vasodilation; however, it is unclear whether intermittent exercise has a different effect on vascular endothelial function compared to continuous exercise. This study aimed to compare vascular endothelial function following intermittent exercise including short rest intervals with continuous exercise, both at the anaerobic threshold level. Materials and methods: Peak oxygen consumption (VO2 peak) and anaerobic threshold were measured in physically active healthy young men (n = 12) by breath-by-breath analysis. After completion of intermittent exercise consisting of eight 1-min long intervals at the anaerobic threshold intensity with 75-s rest periods, total work was calculated. Equivalent work was done during continuous exercise. Immediately after the two exercise periods, venous blood lactate, endothelial nitric oxide synthase (eNOS), endothelin-1, N-terminal proANP (NTproANP), N-terminal proBNP (NTproBNP), and N-terminal proCNP (NTproCNP) levels were measured. Brachial artery flow-mediated dilatation (FMD) was measured before exercise and 30 min after exercise. Results: Mean VO2 peak level was 33.42 ± 5.9 ml/min/kg and anaerobic threshold level was 47.33 ± 5.85%. Lactate levels following continuous exercise were higher than levels following intermittent exercise (27.76 ± 7.43 mg/dl, 18.54 ± 4.87 mg/dl respectively; p˂0.05). Endothelin-1, eNOS, NTproANP, NTproBNP, and NTproCNP levels were similar after both modalities of exercise (p > 0.05). No significant difference was found in FMD response when comparing intermittent and continuous exercise (7.05 ± 15.11%, 2.49 ± 16.24% respectively; p > 0.05). Conclusion: Since blood lactate levels are higher following continuous exercise, individuals who find difficulty exercising may prefer an intermittent form of exercise. However, both intermittent and continuous exercise at the anaerobic threshold level seem to not produce a significant acute change in endothelial function in healthy men.

High-intensity interval training acutely alters plasma adipokine levels in young overweight/obese women.

The aim of this study was to investigate the plasma adipokine responses to high-intensity interval training (HIT) in overweight/obese women. Twelve women (age 21.7 ± 3.8 years) completed a 19 days of HIT comprising six session of 4-6 repeats of a Wingate test (0.065 kg load/kg). Plasma adipokine levels were measured before exercise, and at 5 and 90 min after exercise on the first and the last training days. Adiponectin was higher at 5 min than 90 min post-exercise (11.7 ± 7.3 and 10.5 ± 5.8 ng/ml; p = .01) in the first exercise day. Leptin decreased 5 min after exercise (23.6 ± 13.2 vs. baseline 27.8 ± 14.4 ng/ml; p < .01) and remained depressed following 90 min (p < .01). The changes in adiponectin and leptin concentrations were similar on the first and last exercise days. No consistent effect was found on resistin concentration. Future studies are required to disclose the functional consequences of these alterations in plasma adipokine levels.

The alteration of asymmetric dimetilarginine (ADMA) levels in cardiac and gastrocnemius muscles following radioactive iodine application in guinea pigs and the effect of L-carnitine on this alteration.

PURPOSE: Tissue levels of asymmetric dimetilarginine (ADMA) and symmetric dimetilarginine (SDMA) were investigated in cardiac ventricle and gastrocnemius muscles of guinea pigs treated with radioactive iodine (RAI) alone or in combination with L-carnitine (LC). MATERIAL AND METHODS: Group 1 received no treatment (control group). Group 2 received a total dose of 30 mCi⁻¹kg⁻¹ body weight iodine-131 alone. Group 3 received 200 mg⁻¹kg⁻¹ of LC for 10 days alone. Group 4 received 200 mg⁻¹kg⁻¹ of LC plus RAI therapy. Free thyroid hormones, ADMA and SDMA concentrations were measured. RESULTS: Serum free thyroid hormone concentrations were found decreased in the RAI and LC-RAI groups after RAI application. A significant decrease in ADMA and SDMA concentration was observed in ventricle muscle following RAI application. The LC-RAI group had significantly decreased ADMA levels in ventricle muscle compared with those of the control group. Similarly, SDMA concentrations in ventricle and gastrocnemius muscles of the LC-RAI groups were significantly lower than those of the control groups. CONCLUSIONS: Our results indicated that RAI appears to exert an inhibitory effect on ADMA and SDMA levels of ventricular muscle. LC administration when given adjuvant to RAI therapy may cause a marked decrease in ADMA concentrations of both ventricular and gastrocnemius muscles.