Do we have to reconsider the guidelines for exercise intensity determination in cardiovascular rehabilitation?

Davos, Constantinos H.

doi:10.1177/2047487319871870

Cited by 7 publications

(5 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cardiac hypertrophy is characterized by myocyte hypertrophy, structural rearrangement, and the accumulation of cardiac collagen ( Krzesiak et al, 2017 ). Following exercise training in humans and animal models, heart mass typically increases ( Wang et al, 2010 ; Davos, 2019 ). Macroscopically, we found that the increases in the size of the hearts in the running groups were more obvious after 4 and 8 weeks.…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, although pathological hypertrophy is initially induced as a compensatory response to the growth of the ventricle, this kind of hypertrophy progresses to ventricular chamber dilatation, with wall thinning through the loss of myocytes and contractile dysfunction, resulting in adverse cardiovascular events ( Nakamura and Sadoshima, 2018 ). The impact of endurance exercise on heart health depends on the combination of intensity, time duration, frequency, and exercise type ( Davos, 2019 ). However, less is known regarding cardiac adaptations to the different intensities of treadmill running in rats.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cardiac Effects of Treadmill Running at Different Intensities in a Rat Model

Yan

Zeng

et al. 2021

Front. Physiol.

View full text Add to dashboard Cite

Purpose: In this study, we investigated the effect of treadmill exercise training on cardiac hypertrophy, collagen deposition, echo parameters and serum levels of cardiac troponin I (cTnI) in rats, and how they differ with various exercise intensities, hence exploring potential signal transduction.Methods: Male Sprague-Dawley rats were randomly divided into sedentary (SED), low-intensity running (LIR), medium-intensity running (MIR), and high-intensity running (HIR) groups. Each exercise group had 3 subgroups that were sacrificed for cardiac tissue analyses at 1, 4, and 8 weeks, respectively, and all rats participated in a daily 1 h treadmill routine 5 days per week. Echocardiographic measurements were performed 24 h after the last exercise session. Additionally, myocardium samples and blood were collected for histological and biochemical examinations. Changes in the extracellular signal-regulated kinases 1/2 (ERK1/2) signal pathway were detected by Western blotting.Results: After a week of running, ventricular myocyte size and the phosphorylation of ERK1/2 increased in the HIR group, while left ventricular (LV) diastolic diameter values and LV relative wall thickness increased in the LIR and MIR groups. In addition, we observed heart enlargement, cTnI decrease, and ERK1/2 signal activation in each of the exercise groups after 4 weeks of running. However, the HIR group displayed substantial rupture and increased fibrosis in myocardial tissue. In addition, compared with the LIR and MIR groups, 8 weeks of HIR resulted in structural damage, fiber deposition, and increased cTnI. However, there was no difference in the activation of ERK1/2 signaling between the exercise and SED groups.Conclusion: The effect of running on cardiac hypertrophy was intensity dependent. In contrast to LIR and MIR, the cardiac hypertrophy induced by 8 weeks of HIR was characterized by potential cardiomyocyte injury, which increased the risk of pathological development. Furthermore, the ERK signaling pathway was mainly involved in the compensatory hypertrophy process of the myocardium in the early stage of exercise and was positively correlated with exercise load. However, long-term exercise may attenuate ERK signaling activation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cardiac Effects of Treadmill Running at Different Intensities in a Rat Model

Yan

Zeng

et al. 2021

Front. Physiol.

View full text Add to dashboard Cite

show abstract

“…In contrast, although pathological hypertrophy is initially induced as a compensatory response to growth of the ventricle, this kind of hypertrophy progresses to ventricular chamber dilatation, with wall thinning through loss of myocytes and contractile dysfunction, resulting in adverse cardiovascular events [10]. The impact of endurance exercise on heart health depends on the combination of intensity, time duration, frequency, and type [11]. However, less is known regarding cardiac adaptations to the different intensities of treadmill running in rats.…”

Section: Introductionmentioning

confidence: 99%

Cardiac Effects of Treadmill Running With Different Intensities in a Rat Model

Yan

Zeng

et al. 2021

Preprint

View full text Add to dashboard Cite

Purpose: Exercise is an effective intervention for both the prevention and treatment of cardiovascular diseases. In this study, we investigated the structural and functional changes that occur in cardiac response and how they diﬀer with various exercise intensities, hence exploring the potential signal transduction.Methods: Male Sprague–Dawley rats were randomly divided into the sedentary (SED), low-intensity running (LIR), medium-intensity running (MIR), and high-intensity running (HIR) groups. Each exercise group had 3 different operation time subgroups for 1, 4, and 8 weeks, respectively, and all rats observed a daily 1 h treadmill routine 5 days per week. Echocardiographic measurements were performed at the end of the experimental program. Additionally, myocardium samples and blood were collected for histological and biochemical examinations. Changes in the extracellular signal-regulated kinases 1/2 (ERK1/2) signal pathway were detected by Western blotting.Results: After a week of running, ventricular myocyte size and the phosphorylation of ERK1/2 increased in the HIR group, while left ventricular (LV) diastolic diameter values and LV relative wall thickness increased in the LIR and MIR groups. In addition, we observed heart enlargement, cTnI decrease, and ERK1/2 signal activation in each of the exercise groups after 4 weeks of running. However, the HIR group displayed a substantial rupture and increased fibrosis in myocardial tissue. In addition, compared with the LIR and MIR groups, 8 weeks of HIR resulted in structural damage, fiber deposition, and increased cTnI. However, there was no difference in activation of ERK1/2 signaling between the exercise groups and SED group.Conclusions: The effect of running on cardiac hypertrophy was intensity dependent. In contrast to LIR and MIR, 8 weeks of HIR-induced cardiac hypertrophy was characterized by potential cardiomyocyte injury, which increased the risk of pathological development. Furthermore, the ERK signaling pathway was mainly involved in the compensatory hypertrophy process of the myocardium in the early stage of exercise and was positively correlated with exercise load. However, long-term exercise may attenuate ERK signaling activation.

show abstract

“…Current guidelines suggest intensity prescription in percent of peak effort, ranging from 40% to 80% of peak oxygen consumption ( _ VO 2 ), 50-90% of peak heart rate (HR), or 40-70% of HR reserve [3]. Significant inconsistencies between different guidelines and discrepancies in threshold-based intensities were found in a recent study on patients undergoing CR [5], upon which the need of reconsidering the current guidelines for exercise prescription in the CR setting has been discussed [6]. The need for clearer guidelines, however, may only be indicated if training intensity plays an important role for the improvement in exercise capacity.…”

Section: Introductionmentioning

confidence: 99%

Training intensity and improvements in exercise capacity in elderly patients undergoing European cardiac rehabilitation – the EU-CaRE multicenter cohort study

et al. 2020

View full text Add to dashboard Cite

Objectives Guidelines for exercise intensity prescription in Cardiac Rehabilitation (CR) are inconsistent and have recently been discussed controversially. We aimed (1) to compare training intensities between European CR centres and (2) to assess associations between training intensity and improvement in peak oxygen consumption (V˙O2) in elderly CR patients. Methods Peak V˙O2, heart rate and work rate (WR) at the first and second ventilatory thresholds were measured at start of CR. Training heart rate was measured during three sessions spread over the CR. Multivariate models were used to compare training characteristics between centres and to assess the effect of training intensity on change in peak V˙O2. Results Training intensity was measured in 1011 out of 1633 EU-CaRE patients in 7 of 8 centers and the first and secondary ventilatory threshold were identified in 1166 and 817 patients, respectively. The first and second ventilatory threshold were found at 44% (SD 16%) and 78% (SD 9%) of peak WR and 78% (SD 9%) and 89% (SD 5%) of peak heart rate, respectively. Training intensity and session duration varied significantly between centres but change in peak V˙O2 over CR did not. Training above the first individual threshold (β 0.62, 95% confidence interval [0.25–1.02]) and increase in training volume per hour (β 0.06, 95%CI [0.01–0.12]) were associated with a higher change in peak V˙O2. Conclusion While training intensity and volume varied greatly amongst current European CR programs, changes in peak V˙O2 were similar and the effect of training characteristics on these changes were small.

show abstract

Do we have to reconsider the guidelines for exercise intensity determination in cardiovascular rehabilitation?

Cited by 7 publications

References 16 publications

Cardiac Effects of Treadmill Running at Different Intensities in a Rat Model

Cardiac Effects of Treadmill Running at Different Intensities in a Rat Model

Cardiac Effects of Treadmill Running With Different Intensities in a Rat Model

Training intensity and improvements in exercise capacity in elderly patients undergoing European cardiac rehabilitation – the EU-CaRE multicenter cohort study

Contact Info

Product

Resources

About