Exercise for a Fit Heart

As part of a healthy lifestyle, exercise routines and increased movement specifically contribute to improved cardiovascular fitness, reduced systemic inflammation,2,3 and a lower risk of cardiovascular disease (CVD).

Many different types of physical activities, from simple movement to high intensity, are all beneficial for heart health. 

Fitness and the Healthy Heart
According to the American Heart Association, moderate and vigorous aerobic activity, muscle strengthening through resistance training, increasing daily movement while decreasing sedentary behaviour, and adding intensity to physical activity are among the recommendations for enhancing cardiorespiratory fitness in adults. 

Flexibility and balance training are additional functional medicine exercise strategies, and the benefits of specific exercise routines and activities continue to be studied to determine the impacts of each on prevention and improvement of cardiovascular health. A recent controlled trial (n=39) found that 12 weeks of passive stretching training of the lower limbs (five 40-minute sessions per week) improved blood pressure, arterial stiffness, and vascular function in the arteries directly and not directly involved in the targeted areas. Studies continue to clarify the mechanisms by which stretching training improves cardiac autonomic function; increases in baroreflex sensitivity, relaxation, and nitric oxide bioavailability seem to play important roles.

AEROBIC, RESISTANCE, AND COMBINED TRAINING
Aerobic and resistance training programs may have different routines, but both have shown similar benefits for cardiovascular fitness. Two 2020 randomised controlled trials (RCTs) investigated the heart health impact of aerobic, resistance, and combination training for patients with hypertension and found that all three types of training significantly decreased blood pressure levels. In addition, a 2021 systematic review of 15 RCTs found that compared to only aerobic or resistance training, a combined exercise routine that included aerobic plus resistance training was the most effective for improving weight, waist circumference, and diastolic blood pressure as well as for controlling glucose, insulin, and total triglyceride levels.

INTERVAL AND CONTINUOUS TRAINING
Two recent meta-analyses compared the effectiveness of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in patients with hypertension and within cardiac rehabilitation programs.

A 2020 meta-analysis found that both interventions increased the maximal oxygen uptake (VO2max) for hypertensive patients compared to control groups and promoted a reduction in systolic blood pressure, while HIIT decreased diastolic blood pressure to a greater extent.

Investigators concluded that overall, HIIT may be more beneficial for improvement of cardiorespiratory fitness in hypertensive patients. A second meta-analysis of eight studies (n=387) found that for post-myocardial infarction patients, HIIT was superior to MICT and routine physical activity in improving exercise capacity and cardiorespiratory fitness with a reported mean difference of 0.383 mL/kg/min in VO2peak measurements. In addition, HIIT was reported to be as safe as MICT for this population.

DANCING, WALKING, AND RUNNING
Dancing, walking, and running are aerobic exercises that benefit heart function by improving cardiovascular fitness. For hypertensive patients, research studies have shown dancing’s positive impact through the reduction of systolic and diastolic blood pressure compared to control groups.

A 2018 RCT compared the effects of 60-minute sessions of dancing (3x/week), walking (3x/week), or stretching (1x/week) for eight weeks on cardiovascular risk for sedentary women over 60 years of age.Results indicated:

• Those who followed either the dancing or walking routines had similar increases in peak oxygen consumption (VO2peak) and improvements in balance and lower body muscle strength while those in the active control group (stretching) did not.
• All routines resulted in improved cholesterol, C-reactive protein and TNF-α levels, flexibility, and daily physical activity levels.

A 2020 systematic review of 17 prospective studies (n>30,000) suggested that adding 1,000 walking steps per day helps to lower the risk of all-cause mortality and CVD morbidity and mortality in adults.The review indicated that for each 1,000 daily step count increase at baseline, estimated risk reductions were 6-36% for all-cause mortality and 5-21% for CVD at follow-up. Further, while the number of daily steps needed for optimal health is not clear, studies indicate health benefits are present below 10,000 steps per day.

PILATES, TAI CHI, AND YOGA
Increasing daily movement, even in low-impact ways, is essential for improving heart health. Similar to dancing, Pilates training addresses flexibility, strength, and balance. Specific to cardiovascular fitness, results from recent RCTs suggest that Pilates is an effective intervention for the improvement of vascular function and blood pressure in hypertensive patients and in populations at risk for hypertension. A 2020 meta-analysis of RCTs investigated the effects of tai chi exercises on CVD risk factors and quality of life for patients with essential hypertension. Results indicated that for this population, tai chi reduced blood pressure, total cholesterol, triglycerides, LDL-C, and blood glucose while improving quality of life.

Recent meta-analyses also continue to suggest the cardiovascular benefits of practising yoga. In 2019, a meta-analysis of 49 controlled trials (n=3,517) found that yoga interventions (practised 4.8+/-3.4 sessions per week; 59.2+/-25 minutes per session; 13.2+/-7.5 weeks) resulted in moderate reductions in systolic and diastolic blood pressure compared with controls. In addition, for hypertensive patients that specifically practised yoga interventions that included breath work or meditation/mental relaxation three times per week, greater blood pressure reductions were noted.

 A 2022 meta-analysis of 34 RCTs that included hypertensive adults reported that overall, yoga interventions reduced systolic and diastolic blood pressure compared to controls with mean differences of -6.49 and -2.78, respectively.24 The study found that the effective yoga interventions most commonly incorporated asana, pranayama, and dhyana and relaxation practices and were mostly 45-minute sessions done seven days per week for 12 weeks.

Circadian Impacts
Research suggests that coordinating exercise timing with a patient’s chronotype may optimise the health benefits of exercise routines. Chronotype is based on a person’s underlying clock and refers to their predisposition toward either early or late sleep/wake cycles, or in between those two extremes. Exercise may also be used as a zeitgeber (timing cue) to reset potentially disrupted molecular circadian clocks.25 A 2020 randomised clinical study investigated whether timed exercise interventions impacted internal circadian rhythm through phase shifts, defined as the delay/advancement of wake-up times and bedtimes. The study focused on sedentary adults and measured dim light melatonin onset before and after either five days of morning (n=26) or evening (n=26) exercise. Results indicated that morning exercise induced greater phase advance shifts than evening exercise. In addition, researchers concluded that “late” chronotypes may have circadian benefit from morning or evening exercise while evening exercise may promote circadian misalignment for “early” chronotypes.

References

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Thompson G, Davison GW, Crawford J, Hughes CM. Exercise and inflammation in coronary artery disease: a systematic review and meta-analysis of randomised trials. J Sports Sci. 2020;38(7):814-826. doi:1080/02640414.2020.1735684
Alizaei Yousefabadi H, Niyazi A, Alaee S, Fathi M, Mohammad Rahimi GR. Anti-inflammatory effects of exercise on metabolic syndrome patients: a systematic review and meta-analysis. Biol Res Nurs. 2021;23(2):280-292. doi:1177/1099800420958068
Cleven L, Krell-Roesch J, Nigg CR, Woll A. The association between physical activity with incident obesity, coronary heart disease, diabetes and hypertension in adults: a systematic review of longitudinal studies published after 2012. BMC Public Health. 2020;20(1):726. doi:1186/s12889-020-08715-4
Nichols S, McGregor G, Breckon J, Ingle L. Current insights into exercise-based cardiac rehabilitation in patients with coronary heart disease and chronic heart failure. Int J Sports Med. 2021;42(1):19-26. doi:1055/a-1198-5573
American Heart Association editorial staff. American Heart Association recommendations for physical activity in adults and kids. American Heart Association. Reviewed April 18, 2018. Accessed October 18, 2022. https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults
Bisconti AV, Cè E, Longo S, et al. Evidence for improved systemic and local vascular function after long-term passive static stretching training of the musculoskeletal system. J Physiol. 2020;598(17):3645-3666. doi:1113/JP279866
Wong A, Figueroa A. Effects of acute stretching exercise and training on heart rate variability: a review. J Strength Cond Res. 2021;35(5):1459-1466. doi:1519/jsc.0000000000003084
Pires NF, Coelho-Júnior HJ, Gambassi BB, et al. Combined aerobic and resistance exercises evokes longer reductions on ambulatory blood pressure in resistant hypertension: a randomized crossover trial. Cardiovasc Ther. 2020;2020:8157858. doi:1155/2020/8157858
 Pedralli ML, Marschner RA, Kollet DP, et al. Different exercise training modalities produce similar endothelial function improvements in individuals with prehypertension or hypertension: a randomized clinical trial [published correction appears in Sci Rep. 2020;10(1):10564]. Sci Rep. 2020;10(1):7628. doi:1038/s41598-020-64365-x