Researchers emphasize, however, that PH patients should only exercise under the guidance of PH and rehabilitation specialists.
The study, “Exercise Training and Rehabilitation in Pulmonary Hypertension,” was published in the journal Heart Failure Clinics.
An increasing number of studies have argued that regular exercise is beneficial for PH patients. Many trials suggest that exercising reduces disease symptoms, improves patients’ physical abilities, and has a positive effect on their quality of life.
Based on positive results from several trials, both the European Society of Cardiology and European Respiratory Society recommend supervised and closely monitored exercise and respiratory training as an add-on to medication for PH patients.
However, PH patients need to be extremely careful and consult with their physicians to find a safe and sensible training program, because too much physical effort can lead to exhaustion, right heart failure, or even sudden cardiac death.
In this review, researchers summarize the results of several clinical trials evaluating the clinical impact of exercise and different training approaches in PH, and discuss the potential mechanisms behind the benefits of exercise and future research questions.
In the first randomized, controlled trial addressing the effects of exercise on PH patients, the training program improved the patients’ physical capacity, measured using the 6-minute walking distance (6MWD). Those exercising were able to walk longer distances — a mean of 96 meters more — after 15 weeks of training, compared with the control group.
Exercise also improved quality of life scores, workload, and peak oxygen consumption — the maximum rate of oxygen consumption measured during increasingly intense exercise.
Other clinical trials and observational studies indicate similar benefits, as well as showing that PH patients in the poorest physical condition are the ones more likely to benefit from exercise.
Further studies showed an improvement in overall activity level, breathing efficiency, and peak oxygen pulse — the consumption of oxygen per heartbeat during exercise.
Strength of limb muscles and breathing muscles, which are generally weakened in PH patients, also seems to get better after regular exercise. A 12-week cycling and quadriceps (thigh) muscle training program increased muscle strength by 13% and endurance by 34% in patients with idiopathic pulmonary arterial hypertension.
A small study where patients received in-hospital training showed that exercise improved the patients’ strength of breathing muscles; and a pooled analysis of several studies reinforces evidence of the positive impact of exercise on the muscular function of patients.
Preliminary results also indicate that exercise improves measures of blood flow, called hemodynamics. One study reports that after 15 weeks, mean pulmonary vascular resistance and cardiac index improved up to 15 to 20% with exercise.
The physical benefits of exercise also appear to bring positive changes in patients’ quality of life. A pooled analysis found that exercise leads to significant improvements in physical functioning, physical role performance, general health, social functioning, and emotional role performance.
Although no trials have specifically addressed the effects of exercise on survival and PH progression, many related studies suggest a good survival rate — between 80 and 100% — for patients who exercise over a follow-up period of up to three years.
Overall, exercise was seen to benefit the physical capacity, quality of life, hemodynamics, and possibly disease progression and survival in PH patients. This may also imply a reduction in healthcare costs for these patients.
Despite that, “there remains a lack of knowledge regarding the best methodology, the effects on the right heart … and the underlying mechanisms of exercise training in PH,” the researchers wrote.
Most tested training programs include stationary bicycle or treadmill exercises in combination with further endurance or strength training.
But due to the high risks of physical activity for PH patients, current guidelines recommend that exercise only be done “in specialized centers including both PH specialists as well as rehabilitations specialists who are experienced in exercise training of severely compromised patients,” according to the authors, who add that “the inpatient setting is supported by most of the data and offers several advantages.”
Possible underlying mechanisms of exercise’s effects include the improved efficiency of oxygen use by muscles, which increases their strength; improvements in lung blood flow; and a reduction in inflammation.
However, the researchers conclude that “larger, multicenter, randomized controlled trials are needed to confirm and broaden the knowledge about rehabilitation in PH.”