Future Directions in Swimming Studies

Swimming has long been a popular recreational activity, but is recently gaining widespread acclaim as an effective option in maintaining and improving cardiovascular fitness. In the United States, swimming is second behind walking as the most popular sports activity [1]. Internationally, there are a reported 18,784 facilities with 20,108 full size year round swimming pools in 168 countries. Its appeal for obese, elderly, patients with arthritis, and those with cardiovascular disease primarily Because it does not involve bearing of bodyweight, due to the buoyancy of water, compressive joint forces are lower and, as a consequence, adverse impact on the musculoskeletal system as well as injuries are rare.[13,14]  Indeed, the incidence of orthopaedic injury among swimmers is substantially lower than in runners or cyclists.[14].  In spite of the widespread popularity of swimming,[16-21]  not much is known about the effects of regular swimming for health promotion and disease prevention. The aforementioned exercise recommendations have generated from unjustified extrapolation of the data from other modes of exercise. This is unfortunate because the general public expects that the authoritative advices from medical and scientific bodies are supported and justified by scientific studies.

Traditionally, the exercise component of patients with cardiovascular disease is a land-based training modality using treadmills, exercise bicycles, and strengthening equipment alone or in combination. However, there are patients with establish cardiovascular disease who may benefit but are unable to participate in land-based exercise programs due to comorbidities such as obesity, osteoporosis, and arthritis. These comorbidities may make exercise on land too strenuous or potentially harmful. To address the special needs of patients with such comorbidities.  Thus, swimming training is established as an integrated part of treatment regimes in both patients with myocardial infarction (MI) and chronic congestive heart failure (CHF). However, no data are available on the efficacy of habitual swimming exercise for treating vascular dysfunction in adults with clinical CVD or risk factors for CVD. A practical, but important issue, in clinical practice exercise is the volume and intensity of swimming exercise that are safe for patients. Investigation aimed at determining the efficacy of regular swimming exercise in treating large elastic artery stiffness and vascular endothelial dysfunction in middle-aged and older adults with CVD risk factors and/or clinical CVD are warranted. Very little is known about the mechanisms by which habitual exercise influences vascular function. The main limitation with human investigations is a lack of access to internal (nonperipheral) arteries for tissue sampling and manipulation of signaling pathways, particularly in healthy adults. In vivo and in vitro animal and vascular cell models, as well as innovative methods in humans, will be needed to pursue these issues. One potential mechanism previously implicated in land-based exercise studies is reduced oxidative stress. Studies aimed at identifying the anti-vascular aging effects of swimming exercise mediated in part by suppressing the development of oxidative stress are needed because it can be investigated in human.