An attempt to design optimal personalized exercise prescriptions using the KEIO-SENIOR treadmill protocol for patients with type 2 diabetes

Abstract

We evaluated the effectiveness of new treadmill protocol KEIO-SENIOR. Fifty Japanese patients with diabetes (mean ± standard deviation age, 52.7 ± 11.7 years) had undergone medical examinations using the KEIO-SENIOR protocol. The protocol, for the exercise test, was as follows: the treadmill speed was initially set at 3.2 km/h. The grade was set at 0% initially, and was subsequently increased by 3% every 2 min until 10 min. After that, the grade was not changed; however, the speed was increased by 0.8 km/h every 2 min until the end of the test. The end-points of the test included reaching the target heart rate (THR: 0.85 × [220 − age]); symptoms, such as shortness of breath and leg fatigue; increase in a blood pressure; changes in ECG. The average stage reached by the patients at the end-point was 7.3 ± 1.7, and the average exercise endurance time was 832.1 ± 206.1 s. Regarding end-points, 31 subjects reached the THR and 19 developed the described symptoms. Based on these findings, for subjects who reached the THR, we designed an exercise prescription for each patient based on the heart rate equivalent to 50% of the maximum oxygen consumption using the formula of Karvonen. For others, we prescribed an exercise program based on the optimal heart rate and pace, with reference to the heart rate at the end-point. After 6 months, significant improvements in the blood pressure, body mass index (changed from 27.7 ± 5.4 to 27.1 ± 5.3 kg/m² [p = 0.009]), and HbA1c (changed from 7.8 ± 2.0 to 7.2 ± 1.8% [p = 0.011]) were observed. In conclusion, our results suggest that this protocol, the main purpose of which was not to detect coronary ischemia, was a useful tool to evaluate physical fitness and to prescribe exercises for middle-aged or elderly Japanese patients.