Effects of high-load and low-load resistance training in patients with coronary artery disease: rationale and design of a randomised controlled clinical trial

Insulin resistance, lipids and body composition in patients with coronary artery disease after combined aerobic training and resistance training: a randomised, controlled trial

BACKGROUND

The effect of resistance training (RT) in cardiac rehabilitation (CR) on insulin resistance remains elusive. We examined whether the addition of high-load (HL) or low loads (LL) RT has any effect on the levels of insulin resistance and lipids versus aerobic training (AT) alone in patients with coronary artery disease (CAD).

METHODS

Seventy-nine CAD patients were randomised to HL-RT [70-80% of one repetition maximum (1-RM)] and AT, LL-RT (35-40% of 1-RM) and AT or AT (50-80% of maximal power output), and 59 patients [75% males, 15% diabetics, age: 61 (8) years, left ventricular ejection fraction: 53 (9) %] completed the study. Plasma levels of glucose, insulin, blood lipids [total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL)] cholesterol and body composition were measured at baseline and post-training (36 training sessions).

RESULTS

Training intervention had only time effect on lean mass (p = 0.002), total and LDL cholesterol levels (both p < 0.001), and no effects on levels of glucose and insulin resistance (homeostatic assessment 2-insulin resistance). Total and LDL cholesterols levels decreased following AT [mean difference (95% confidence interval); total cholesterol: - 0.4 mmol/l (- 0.7 mmol/l, - 0.1 mmol/l), p = 0.013; LDL: - 0.4 mmol/l (- 0.7 mmol/l, - 0.1 mmol/l), p = 0.006] and HL-RT [total cholesterol: - 0.5 mmol/l (- 0.8 mmol/l, - 0.2 mmol/l), p = 0.002; LDL: - 0.5 mol/l (- 0.7 mmol/l, - 0.2 mmol/l), p = 0.002]. No associations were observed between post-training change in body composition and post-training change in blood biomarkers.

CONCLUSIONS

RT when combined with AT had no additional effect beyond AT alone on fasting glucose metabolism, blood lipids and body composition in patients with CAD. Trial registration number NCT04638764.

Physical activity and sedentary behaviour following combined aerobic and resistance training in coronary artery disease patients: A randomised controlled trial

BACKGROUND

Effective training modalities and potential determinants to induce favourable changes in physical activity (PA) and sedentary behaviour (SB) remains elusive in patients with coronary artery disease.

AIMS

This study aimed to investigate the effects of high-load resistance training and low-load RT combined with aerobic training in comparison to aerobic training alone on PA and SB, and whether baseline level of SB modifies PA outcomes in coronary artery disease patients.

METHODS

We randomised 79 patients to aerobic training, low-load resistance training and aerobic training or high-load resistance training and aerobic training. PA and SB were measured using triaxial accelerometer at baseline and post-training for 8 days.

RESULTS

There was no difference between training modalities in post-training PA and SB. When stratified by baseline SB, the very sedentary patients improved SB (-52 min/day, p = 0.001) and light intensity PA (+27 min/day, p = 0.009) following intervention. The improvement in PA was greater in the very sedentary patients (SB: +27%, p = 0.002; light intensity PA: +24%, p = 0.004) and in sedentary patients (SB: +24%, p = 0.009) compared to the very active patients.

CONCLUSIONS

Post-training improvement in PA and SB was determined by baseline SB, while the addition of low-load or high-load resistance training provided no further benefits in coronary artery disease patients.

CLINICAL TRIALS REGISTRATION NUMBER

NCT04638764.

Combined resistance training with aerobic training improves physical performance in patients with coronary artery disease: A secondary analysis of a randomized controlled clinical trial

Background

The efficacy of combined resistance training (RT) and aerobic training (AT) compared with AT alone is well established in cardiac rehabilitation (CR); however, it remains to be elucidated whether RT load (high load [HL] vs. low load [LL]) modifies the outcomes. The aim of our study was to investigate the effects of HL-RT and LL-RT combined with AT in comparison to AT alone on body composition and physical performance in patients with coronary artery disease (CAD) enrolled in phase II CR.

Methods

We randomized 79 patients with a stable CAD to 12 weeks of lower limb LL-RT + AT (35-40% of one repetition maximum [1-RM]; n = 28), HL-RT + AT (70-80% of 1-RM; n = 26), or AT (n = 25). Fifty-nine patients (75% men) with mean (standard deviation) age 61 (8) years and left ventricular ejection fraction 53 (9)% completed LL-RT (n = 19), HL-RT (n = 21) and AT (n = 19). Body composition and physical performance (upper and lower submaximal muscle strength, flexibility, balance, and mobility) were measured at baseline and post-training.

Results

Training intervention had no significant impact on time × group interaction in the body composition measures. There was a significant time × group interaction for the gait speed test, chair sit-and-reach test, arm curl test, Stork balance test, up and go test, STS-5, and 6-min walk distance (p-values ≤ 0.001-0.04) following the training intervention. After the training intervention, HL-RT improved gait speed (+12%, p = 0.044), arm curl (+13%, p = 0.037), and time of Up and Go test (+9%, p < 0.001) to a greater extent compared with AT group, while there was a greater improvement in time of Up and Go test (+18%, p < 0.001) and time of five sit-to-stand tests (+14%, p = 0.016) following LL-RT when compared with AT. There were no differences between HL-RT and LL-RT in post-training improvement in any of the physical performance measures.

Conclusion

The combination of AT with HL-RT or LL-RT promoted similar improvements in physical performance, which were superior to AT. Therefore, both types of combined AT and RT can be applied to patients with CAD.

Clinical trial registration

[https://clinicaltrials.gov/ct2/show/NCT04638764] Identifier [NCT04638764].

High-Load and Low-Load Resistance Exercise in Patients with Coronary Artery Disease: Feasibility and Safety of a Randomized Controlled Clinical Trial

Resistance exercise (RE) remains underused in cardiac rehabilitation; therefore, there is insufficient evidence on safety, feasibility, and hemodynamic adaptations to high-load (HL) and low-load (LL) RE in patients with coronary artery disease (CAD). This study aimed to compare the safety, feasibility of HL-RE and LL-RE when combined with aerobic exercise (AE), and hemodynamic adaptations to HL and LL resistance exercise following the intervention. Seventy-nine patients with CAD were randomized either to HL-RE (70−80% of one-repetition maximum [1-RM]) and AE, LL-RE (35−40% of 1-RM) and AE or solely AE (50−80% of maximal power output) as a standard care, and 59 patients completed this study. We assessed safety and feasibility of HL-RE and LL-RE and we measured 1-RM on leg extension machine and hemodynamic response during HL- and LL-RE at baseline and post-training. The training intervention was safe, well tolerated, and completed without any adverse events. Adherence to RE protocols was excellent (100%). LL-RE was better tolerated than HL-RE, especially from the third to the final mesocycle of this study (Borgs’ 0−10 scale difference: 1−2 points; p = 0.001−0.048). Improvement in 1-RM was greater following HL-RE (+31%, p < 0.001) and LL-RE (+23%, p < 0.001) compared with AE. Participation in HL-RE and LL-RE resulted in a decreased rating of perceived exertion during post-training HL- and LL-RE, but in the absence of post-training hemodynamic adaptations. The implementation of HL-RE or LL-RE combined with AE was safe, well tolerated and can be applied in the early phase of cardiac rehabilitation for patients with stable CAD.

Objectively Measured Physical Activity in Patients with Coronary Artery Disease: A Cross-Validation Study

Physical activity (PA) and sedentary behavior (SB) levels in healthy adults are predominately based on self-reporting measures, which generally overestimate PA but underestimate SB. Patients with coronary artery disease (CAD) eligible for cardiac rehabilitation (CR) follow an individualized program; thus, objective assessment of physical performance and regular daily activity is required. This study aimed to compare self-reported and objectively measured PA and SB in patients with CAD prior to out-patient CR. We included 91 patients with CAD and assessed their PA with an accelerometer for 8 days prior to CR, along with the short form of the international physical activity questionnaire. We found that most patients were sedentary (61%, ~8 h/day), and on average performed 63 min/day of moderate-to-vigorous-intensity physical activity (MVPA). Males performed less daily light-intensity physical activity (−5%, p = 0.011) and performed more MVPA (+2%, p = 0.002) compared to females. Maximal aerobic capacity was significantly associated with MVPA (Spearman rho = 0.483, p < 0.001) and MVPA > 10 min bouts (Spearman rho = 0.391, p < 0.001). Self-reported measures overestimated MVPA (total MVPA, +108 min/day, p < 0.001; MVPA > 10 min bouts, +152 min, p < 0.001) and underestimated SB (−174 min/day, p < 0.001) compared to objective measures. There was no significant correlation between methods in MVPA (Spearman rho = 0.147, p = 0.165)), MVPA > 10 min bouts (Spearman rho = −0.059, p = 576), and SB (Spearman rho = 0.139, p = 0.187). Quantitative analysis demonstrated the huge proportional bias for MVPA, MVPA > 10 min bouts, and SB. Our findings demonstrate that self-reported physical activity provides inaccurate estimates of MVPA and SB in patients with CAD entering the ambulatory CR. This strongly supports the more objective assessments of daily PA, preferably using an accelerometer.