To evaluate the effect of high-intensity interval training (HIIT) on psychological symptoms, activity states, and cardiovascular functions in patients with myocardial infarction (MI) of low and moderate risk stratification.
This prospective study randomly allocated 44 patients with MI to 18 sessions of HIIT or conventional moderate-intensity continuous training (MICT). Outcome measures were assessed at baseline and after 18 sessions.
Post-exercise cardiovascular and functional states, maximal oxygen uptake (VO2max), metabolic equivalents (METs), 6-Minute Walking Test (6MWT), and Korean Activity Scale/Index (KASI) scores were significantly improved in the HIIT group compared to those in the MICT group after 18 exercise sessions. In particular, VO2max was significantly (p<0.005) improved in the HIIT group (7.58 mL/kg/min) compared to that in the MICT group (2.42 mL/kg/min). In addition, post-exercise psychological states (i.e., scores of Fatigue Severity Scale [FSS] and depression items of the Hospital Anxiety and Depression Scale [HADS_D]) were significantly improved in the HIIT group compared to those in the MICT group after 18 exercise sessions. HADS-D was improved by 1.89 in the HIIT group compared to decrement of 0.47 in the MICT group. FSS was improved by 6.38 in the HIIT group compared to decrement of 0.77 in the MICT group (p<0.005).
This study demonstrates that HIIT can improve cardiac function, psychological, and activity states in low and moderate risk MI patients. Compared to conventional MICT, HIIT can improve cardiovascular functions, activity states, depression, and fatigue more effectively.
Citations
Intensity of Physical Activity and Depressive Symptoms in College Students: Fitness Improvement Tactics in Youth (FITYou) Project
To compare and analyze the effects of cardiac rehabilitation (CR) in two groups based on the peak respiratory exchange ratio (RERpeak) 1.1 values using the exercise tolerance test (ETT) results, and to investigate the reasons for early termination of ETT.
Patients with acute coronary syndrome who participated in CR exercise training were selected and all subjects underwent 6 weeks of CR exercise training. ETT was performed on a treadmill using a Modified Bruce Protocol before and after CR exercise training. According to the result of the first ETT, the subjects were divided into two groups: those with an RERpeak≥1.1 (n=33) and those with an RERpeak<1.1 (n=22). We investigated the reasons for ETT termination and compared the effect of CR between the groups.
The reasons for the early termination of the first ETT in the RERpeak<1.1 group were subjective dyspnea, abnormal cardiovascular responses, leg fatigue and other problems. After a 6-week CR, the peak oxygen consumption (VO2peak) and ETT time increased, and the rate of perceived exertion (RPE) and RPP (rate pressure product) at stage 3 decreased in both the RERpeak<1.1 and RERpeak≥1.1 groups.
CR exercise training improved exercise capacity, not only in the RERpeak≥1.1 group, but also in the RERpeak<1.1 group. This means that patients with a lower exercise tolerance could also benefit from the effects of CR. Thoughtful consideration to identify the direct and indirect causes for the early termination of ETT would be necessary to improve the efficiency of CR.
Citations
To quantify changes in cardiopulmonary function using a lower body positive pressure supported (LBPPS) treadmill during the exercise tolerance test (ETT) in healthy subjects before applying the LBPPS treadmill in patients with gait problems.
We evaluated 30 healthy subjects who were able to walk independently. The ETT was performed using the Modified Bruce Protocol (stages 1–5) at four levels (0%, 40%, 60%, and 80%) of LBPPS. The time interval at each level of the LBPPS treadmill test was 20 minutes to recover to baseline status. We measured systolic blood pressure, diastolic blood pressure, peak heart rate (PHR), rating of perceived exertion (RPE), metabolic equivalents (METs), and oxygen consumption rate (VO2) during each LBPPS condition.
Systolic blood pressure increased as the LBPPS level was increased (40% to 80%). PHR, RPE, METs, and VO2 were negatively associated with the LBPPS condition, although they were not always significant different among the LBPPS levels. The equation from a random effect linear regression model was as follows: VO2 (mL/kg/min)=(2.75×stage)+(–0.14×LBPPS level)+11.9 (r2=0.69).
Detection of the changes in physiological parameters during a submaximal ETT using the LBPPS system may be helpful for applying the LBPPS treadmill in patients who cannot perform the ETT due to gait problems, even at submaximal intensity.
Citations
To evaluate the cardiopulmonary endurance of subjects with spinal cord injury by measuring the maximal oxygen consumption with varying degrees of spinal cord injury level, age, and regular exercise.
We instructed the subjects to perform exercises using arm ergometer on healthy adults at 20 years of age or older with spinal cord injury, and their maximal oxygen consumption (VO2max) was measured with a metabolic measurement system. The exercise proceeded stepwise according to the exercise protocol and was stopped when the subject was exhausted or when VO2 reached an equilibriu
Among the 40 subjects, there were 10 subjects with cervical cord injury, 27 with thoracic cord injury, and 3 with lumbar cord injury. Twenty-five subjects who were exercised regularly showed statistically higher results of VO2max than those who did not exercise regularly. Subjects with cervical injury showed statistically lower VO2max than the subjects with thoracic or lumbar injury out of the 40 subjects with neurologic injury. In addition, higher age showed a statistically lower VO2max. Lastly, the regularly exercising paraplegic group showed higher VO2max than the non-exercising paraplegic group.
There are differences in VO2max of subjects with spinal cord injury according to the degree of neurologic injury, age, and whether the subject participates in regular exercise. We found that regular exercise increased the VO2max in individuals with spinal cord injury.
Citations
To determine if assistive ergometer training can improve the functional ability and aerobic capacity of subacute stroke patients and if functional electrical stimulation (FES) of the paretic leg during ergometer cycling has additional effects.
Sixteen subacute stroke patents were randomly assigned to the FES group (n=8) or the control group (n=8). All patients underwent assistive ergometer training for 30 minutes (five times per week for 4 weeks). The electrical stimulation group received FES of the paretic lower limb muscles during assistive ergometer training. The six-minute walk test (6MWT), Berg Balance Scale (BBS), and the Korean version of Modified Barthel Index (K-MBI) were evaluated at the beginning and end of treatment. Peak oxygen consumption (Vo2peak), metabolic equivalent (MET), resting and maximal heart rate, resting and maximal blood pressure, maximal rate pressure product, submaximal rate pressure product, submaximal rate of perceived exertion, exercise duration, respiratory exchange ratio, and estimated anaerobic threshold (AT) were determined with the exercise tolerance test before and after treatment.
At 4 weeks after treatment, the FES assistive ergometer training group showed significant improvements in 6MWT (p=0.01), BBS (p=0.01), K-MBI (p=0.01), Vo2peak (p=0.02), MET (p=0.02), and estimated AT (p=0.02). The control group showed improvements in only BBS (p=0.01) and K-MBI (p=0.02). However, there was no significant difference in exercise capacity and functional ability between the two groups.
This study demonstrated that ergometer training for 4 weeks improved the functional ability of subacute stroke patients. In addition, aerobic capacity was improved after assisted ergometer training with a FES only.
Citations
To evaluate the effect of neuromuscular electrical stimulation (NMES) on cardiopulmonary function in healthy adults.
Thirty-six healthy adults without a cardiac problem were enrolled. All patients were randomly assigned to either a control (17 subjects, mean age 29.41) or an electrical stimulation group (19 subjects, mean age 29.26). The electrical stimulation group received NMES on both sides of quadriceps muscle using a Walking Man II® in a sitting position for 30 minutes over 2 weeks. Maximum oxygen consumption (VO2max), metabolic equivalent (MET), resting, maximal heart rate (RHR, MHR), resting, maximal blood pressure (RBP, MBP), and maximal rate pressure product (MRPP), exercise tolerance test (ETT) duration were determined using an exercise tolerance test and a 6 minute walk test (6MWT) before and after treatment.
The electrical stimulation group showed a significant increase in VO2max (p=0.03), 6MWT (p<0.01), MHR (p<0.04), MsBP (p<0.03), ETT duration (p<0.01) and a significant decrease in RsBP (p<0.02) as compared with the control group after two weeks. NMES induced changes improved only in RsBP (p<0.049) and ETT duration (p<0.01). The effects of NMES training were stronger in females.
We suggest that NMES is an additional therapeutic option for cardiopulmonary exercise in disabled patients with severe refractory heart failure or acute AMI.
Citations
Objective: The purpose of this study was to investigate the changes of oxygen consumption and heart rate at forward and backward treadmill walking in healthy male college students.
Method: Subjects were composed of twenty healthy male college students. The oxygen consumption, oxygen consumption ratio of maximal oxygen consumption (VO2max%) and heart rate, heart rate ratio of maximal heart rate (HRmax%) were measured for each subjects by administering a treadmill exercise test at 5 km/hr speed of forward and backward walking. Paired t-test was used to evaluate the difference of the forward and backward walking.
Results: The study showed that heart rate and HRmax% were 120.9 beat/min, 61.6% in forward walking, and 166.1 beats/min, 84.3% in backward walking, respectively. The oxygen consumption and VO2max% were 15.9 ml/kg/min, 37.3% in forward walking, and 23.6 ml/kg/min, 55.8% in backward walking, respectively.
Conclusion: We concluded that 5 km/hr backward walking was more effective exercise program than forward walking to promote health in the college students.
Objective: To compare the change of oxygen consumption and heart rate between walking and running at the same condition of treadmill in healthy male college students.
Method: Twenty healthy male college students completed steady-state treadmill test at 3 mph and 5 mph, separately, by walking and running. During the each 6 minutes treadmill test, oxygen consumption (VO2), heart rate (H.R), oxygen consumption ratio of maximal oxygen consumption (% VO2max), and heart rate ratio of maximal heart rate (% HR) were measured each minute.
Results: The showed that mean heart rate were 123.40⁑4.62 beats/min and oxygen consumption were 12.84⁑1.94 ml/kg/min, in 3 mph walking. The mean heart rate were 139.90⁑6.80 beats/min and oxygen consumption were 16.51⁑1.78 ml/kg/min in 5 mph walking. The running showed that mean heart rate were 187.55⁑6.74 beats/min and oxygen consumption were 26.45⁑3.11 ml/kg/min in 3 mph walking. The mean heart rate were 168.45⁑13.34 beats/min and oxygen consumption were 21.05⁑2.00 ml/kg/min in 5 mph walking. There were significant differences (p<0.05) in mean heart rate, VO2 between the 3 mph walking and running, the 5 mph walking and running.
Conclusion: We concluded that 3 mph walking and running and 5 mph running were an effective exercise to promote health in healthy college students.