Strengthergo240

Training was conducted twice weekly on nonconsecutive days for 4 weeks using StrengthErgo 240 stationary cycling exercise machines (Mitsubishi Electric Corporation, Tokyo, Japan). The subjects completed 3 sets of 15 % maximal voluntary contraction (MVC) cycle exercises for 60 s and 7 sets of 20 % MVC cycle exercises for 40 s at 50 rpm.

Individual aerobic fitness level was assessed using a graded exercise test with a recumbent ergometer (Strength-ergo 240, Mitsubishi Electric Corporation, Japan). Peak oxygen uptake ( $\dot{\mathrm{V}}$ O_2peak), the gold-standard measurement of aerobic fitness, was determined by measuring oxygen uptake continuously during an incremental test to exhaustion. After warming up for 3 minutes at 30 W, the work rate increased by 20 W (females: 15 W) per minute in a constant and continuous manner to exhaustion. The pedaling rate was kept at 60 rpm. Exhaled gas was analyzed using a gas analyzer (Aeromonitor AE280S, Minato Medical Science, Japan). Heart rate (HR) and rating of perceived exertion (RPE) were recorded every minute. The RPE was assessed verbally on which participant are asked to rate their perceived exertion ranging from 6 (no exertion at all) to 20 (maximal exertion). $\dot{\mathrm{V}}$ O_2peak was determined when at least two of the following criteria were satisfied: (1) the respiratory exchange ratio (R) exceeded 1.05, (2) achievement of 90% of age-predicted peak HR (220–age), and (3) an RPE of 19 or 20.

The isokinetic leg extension strength of each leg was measured using a StrengthErgo 240 (Mitsubishi Electric Co., Tokyo, Japan). Each subject rode on the apparatus and pedaled at maximum effort five times. The peak muscle strength of the right and left legs was calculated as the maximal isokinetic leg extension strength.

Cardiorespiratory fitness is a strong predictor of mortality in patients with CVD, with CPX commonly used to measure oxygen uptake as an indicator of cardiorespiratory fitness [7 (link),8 (link)]. In this study, CPX and expiratory gas analyses were performed to quantitatively evaluate oxygen uptake (VO₂). CPX measures VO₂, ventilatory carbon dioxide output, and respiratory and ventilation rates. CPX also calculates the minute ventilation rate from these measurements [20 (link)]. In the CPX test, a Strength Ergo 240 (Mitsubishi Electric Engineering Co., Ltd., Tokyo, Japan) was used for exercise load, an AE-310s Aeromonitor (Minato Medical Science Co., Ltd., Osaka, Japan) was used for breath gas analysis, and an STS-2100 (Nihon Kohden Co., Ltd., Tokyo, Japan) was used for exercise load electrocardiogram. In the study protocol, the patients began with a 3 min warm-up on a bicycle ergometer, followed by a 10 watt/min or 20 watt/min ramp incremental protocol. Continuous 12-lead electrocardiography was performed during the assessment, and blood pressure was recorded every minute during the exercise and recovery periods. After reaching the peak load, all patients pedaled at 0 watts, with a cool-down period of ≥2 min to prevent excessive venous pooling. The testing procedure adhered to published guidelines [21 (link)].