Randomised controlled trial in women with coronary artery disease investigating the effects of aerobic interval training versus moderate intensity continuous exercise in cardiac rehabilitation: CAT versus MICE study

Abstract

BackgroundThe primary aim of the present study was to investigate the effects of aerobic interval training (AIT) versus moderate intensity continuous exercise (MICE) on aerobic exercise capacity (V̇O2peak), in women only, with coronary artery disease (CAD) and who were referred to a large, 24-week outpatient cardiac rehabilitation (CR) programme. Secondary objectives included comparing the effects of AIT versus MICE on cognition, cardiovascular risk profile, adherence and quality of life before and after the 24-week CR programme.MethodsThirty-one postmenopausal women with CAD (left ventricular ejection fraction >35%; 68.2±9.2 years of age; V̇O2peak: 19.1±3.5 mL kg-1 min-1) were randomised to 24 weeks of usual care MICE (60%–80% of V̇O2peak, five times per week) or AIT (four 4-min intervals at 90%–95% of peak heart rate, three times per week+two times per week usual care MICE). Differences between and within groups were assessed using independent samples t-tests and paired samples t-tests, respectively. Treatment effect analysis of AIT on V̇O2peak and secondary outcomes was determined using analysis of covariance with baseline values as covariates.ResultsA randomised controlled trial study design was unfeasible in this female CAD population. Unanticipated challenges in recruitment availability and eligibility, in combination with a 59% and 50% attrition rate in the AIT and MICE group, respectively, rendered this study underpowered to detect differences between groups. The per protocol treatment effect analysis, however, unveiled a 0.95 mL kg-1 min-1 improvement in V̇O2peak in response to AIT over MICE (p<0.001).ConclusionsFurther research is necessary to elucidate the patient profile and circumstances under which the potential for the implementation of AIT may be individualised, and offered in clinical practice.Trial registrationNCT02966158.

Can high-intensity interval training improve mental health outcomes in the general population and those with physical illnesses? A systematic review and meta-analysis

“…Following HIIT, no reduction in depression severity compared with active control was found (SMD: –0.129; 95% CI: −0.328 to 0.070; I 2 =0%; n=9) 38 51 53 57 59 67 82 83 86…”

“…Search results are shown in figure 1. Overall, 58 RCTs (N=3038 participants) were included (including three follow-up analyses34–36), encompassing HIIT in adults with no medical comorbidities (n=10, n=577),21 37–45 healthy older adults (n=3, n=142),46–48 adolescents (n=2, n=133),49 50 patients with cardiometabolic disorders (including obesity, hypertension, diabetes, metabolic syndrome (MetS), heart failure, stroke, coronary artery disease (n=35, n=1807),19 20 34–36 51–80 COPD (n=3, n=193),81–83 patients with cancer (n=2, n=78),84 85 Crohn’s disease (n=1, n=36),86 cutaneous systemic sclerosis (SSc) (n=1, n=34)87 and patients undergoing liver resection (n=1, n=38)88 (see figure 1). Mean age of participants ranged from 15.5 to 74.9 years.…”

“…Fifty-three per cent of RCTs prescribed cycling HIIT, 17% prescribed running HIIT and other modalities included boxing, suspension training, resistance training, tennis and mixed-modality sports. Twenty-four RCTs compared HIIT to an active (exercise) control,19 34 35 43 44 47 51–53 56 57 59 63 64 67 69 70 74 76 78 79 81–83 23 RCTs compared HIIT to a non-active control,20 36 37 39 40 45 48–50 58 60–62 65 66 68 72 75 80 84 85 87 88 10 RCTs compared HIIT to both active and non-active conditions21 38 41 42 46 55 71 73 77 86 and 1 RCT compared HIIT to a low-energy diet 54. Where an active control group was prescribed, continuous cycling or jogging was provided on 28 (82%) occasions.…”

“…Supervision was provided in 55 (95%) RCTs, 2 RCTs conducted non-supervised home-based HIIT,75 80 and 1 did not provide supervision details 59. Additionally, in five RCTs participants were asked to conduct extra non-supervised HIIT sessions/supplementary home-based components 20 50 62 64 67. HIIT was mostly supervised by a researcher, physiotherapist or personal trainer, although background of the supervisor was not reported in 19 (33%) RCTs.…”

“…Thirty-six per cent of studies reported motivational strategies, motivational strategies included positive encouragement,35 51 52 71 motivational talks and fitness advice,57 58 75 monetary compensation/gift vouchers,38 49 60 free gym memberships,38 Fitbits38 and certificates 49. It is also important to note that actual intensity reached during HIIT sessions was reported in 31 (53%) RCTs, of which 26 (45%) stated that, on average, the desired heart rate (≥85% HRpeak/equivalent) was reached during high-intensity bursts as per protocol,34 36 37 40 42 45 48–50 59 61 63–69 71 74 82–87 and 5 (9%) RCTs reported that either a lower intensity was averaged/a proportion of participants did not meet the desired intensity,35 41 51 72 81 whereas 27 (47%) RCTs offered no discussion as to whether the HIIT protocol was adhered to 19–21 38 39 43 44 46 47 52–58 60 62 70 73 75–80 88. No study reported modifications to the intervention design.…”