Is this the best exercise for cardio and overall health?

Spending less time on the couch and more time exercising are healthy goals for any physician—and better fitness is a popular resolution this time of year. It’s a good thing, because sedentary behaviors are associated with poor cardiovascular health, insulin resistance, and obesity. These, in turn, can result in a higher risk of cardiovascular disease, dementia, certain cancers, and type 2 diabetes.

Getting regular physical activity—whether it’s running, weightlifting, cycling, swimming, or playing sports—does the reverse. According to CDC guidance, people who are physically active for about 150 minutes a week have a 33% lower risk of all-cause mortality than those who are sedentary.

But not all forms of exercise provide the same benefits, and some evidence suggests that swimming, in particular, might outshine the alternatives.  

So, how, precisely, can swimming help patients? And what do these insights mean?

A full-body workout

While many forms of cardio exercise, like biking or running, require participants to primarily use their lower body muscles, swimming is a genuine full-body workout. Swimming engages not only the leg and arm muscles, but also the upper body and core muscles, like lats, back muscles, and triceps.

Swimming can also help with back pain. Unlike many other forms of cardio, swimming is a workout that requires being horizontal, so there’s a low impact on the back—unlike running or biking. This means it can improve posture and prevent back injuries and chronic pain that might occur after long periods sitting in front of a computer or desk.

And don’t believe for a second that the gravity-defying aspect of floating in water makes the workout any less intense. Because water is denser than air, swimming actually puts more external pressure on the limbs than land training. This resistance is also uniformly distributed, so unlike weightlifting, swimming is unlikely to injure hips, knees, and other vulnerable spots. This full-body resistance elevates heart rate, which can help build strength, endurance, and cardiovascular fitness.

Swimming’s low impact

Water’s buoyancy means that swimming is a low-impact sport. For those with achy joints or more serious conditions like osteoarthritis (OA), weight-bearing physical activities can be painful, so swimming can be the ideal solution. One study looked at 48 middle-aged or older patients with OA who were randomly assigned to swimming or cycling training groups. The authors concluded that “regular swimming exercise can exert similar or even superior effects on vascular function and inflammatory markers compared with land-based cycling exercise in patients with OA who often have an increased risk of developing cardiovascular disease.”

Buoyancy also makes swimming an attractive proposition for people who are overweight or obese. Exercises that are load-bearing, like running, can be uncomfortable or painful experiences for obese individuals. Swimming, on the other hand, not only provides an evenly distributed resistance, but the water keeps bodies cooler and doesn’t involve any risks of injury from falling.  

According to the CDC, water-based exercise can also help patients with rheumatoid arthritis and those who are at risk of falls, for the reasons above.

Effects on neurological conditions

Swimming may have special advantages for people with neurological and neurodegenerative conditions because it promotes balance and can be far safer than land-based training, according to a 2017 report commissioned by Swim England, a UK governing body for swimming.

These attributes of water-based exercise appear to benefit patients with multiple sclerosis (MS), according to a 2017 review published in the European Journal of Physical and Rehabilitation Medicine. For example, one study covered in the review examined the impact of a 20-week “Ai-Chi” aquatic exercise program with a cohort of 73 MS patients. Researchers found that the program improved pain, spasms, disability, fatigue, depression, and autonomy in the patients who took part. 

The authors wrote: “Hydrotherapy is frequently applied to patients with painful neurological or musculoskeletal alterations, because the heat and floatability of the water can block nociceptors by acting on thermal receptors and mechanoreceptors and exert a positive effect on spinal segmental mechanisms.” 

The warm water can also increase blood flow, which helps dissipate allogeneic chemicals, promotes muscle relaxation, and alleviates pain by decreasing peripheral edema and sympathetic nervous system activity.

Lung function benefits?

Swimming also seems to lead to better breathing. In 2018, a systematic review and meta-analysis published in Sports Medicine found that while the effects of swimming on lung function in relation to other exercises were dubious, one study found that swimmers saw significant increases in FEV1% (forced expiratory volume in 1 second) compared to golfers. Further, much prior lung function data focused on children with asthma, leaving researchers with little to work with, according to the review.

But an older study published in the Indian Journal of Physiology and Pharmacology could shed some light. Researchers compared the lung function of 30 swimmers to runners, finding that FEV1% and maximum voluntary ventilation were higher in swimmers. The authors concluded that swimming affects lung volume measurements because respiratory muscles are required to develop greater pressure due to swimmers’ need to hold their breath, thus strengthening these muscles and lung function.

Mental health matters

Water-based activities improve mental health and boost mood across all demographics, but certain people see even greater benefits, according to the CDC. For those with fibromyalgia, for example, exercise therapy in warm water can decrease depression and anxiety. 

According to the Swim England report, studies conducted specifically on swimming have found that the activity is associated with improved life satisfaction, self-perception of health, lower stress levels, and general well-being. While no studies have been conducted comparing the mental health boons of swimming to other forms of exercise, the authors posited that swimming’s inclusiveness means that it stands to improve wellness across more populations than other forms of exercise.