Swimming offers something no other aerobic exercise does: the ability to work your body without harsh impact to your skeletal system. When the human body is submerged in water, it automatically becomes lighter. When immersed to the waist, your body bears just 50 percent of its weight; dunk yourself to the chest and that number reduces to around 25 to 35 percent; with water all the way to the neck, you only have to bear 10 percent of your own weight. The other 90 percent is handled by the pool.
This means that the pool provides an ideal place to work stiff muscles and sore joints, especially if you’re overweight or suffer from arthritis.
In its recommendation for the right types of exercise for people with arthritis, the Arthritis Foundation suggests those that stretch muscles, those that strengthen muscles, and those that provide an aerobic workout. A few laps in the pool combine all three!
If the pool is heated, so much the better for arthritis sufferers, as the warm water can help loosen stiff joints. In fact, people with rheumatoid arthritis receive greater benefits to their health after participating in hydrotherapy than with other activities. It’s also been proven that water-based exercise improves the use of affected joints and decreases pain from osteoarthritis
Ever see a flabby dolphin or a weak-looking competitive swimmer? We didn’t think so. That’s because swimming is a great way to increase muscular strength and muscle tone — especially compared to several other aerobic exercises.
Take running, for example. When a jogger takes few laps around the track, that jogger is only moving his or her body through air. A swimmer, on the other hand, is propelling himself through water — a substance about twelve times as dense as air [source: Yeager]. That means that every kick and every arm stroke becomes a resistance exercise — and it’s well known that resistance exercises are the best way to build muscle tone and strength.
There’s yet another bonus of a watery workout: Swimming has also been shown to improve bone strength — especially in post-menopausal women [Source: Huang, et al.].
Unlike exercise machines in a gym that tend to isolate one body part at a time (like a bicep curl machine, for example), swimming puts the body through a broad range of motion that helps joints and ligaments stay loose and flexible. The arms move in wide arcs, the hips are engaged as the legs scissor through the water, and the head and spine twist from side to side. Plus, with every stroke, as you reach forward, you’re lengthening the body, which not only makes it more efficient in the water, it also helps give you a good stretch from head to toe.
To improve your flexibility beyond the natural gains you’ll make by swimming, you might also want to finish your pool workout with a series of gentle stretches. The support of the water should help you maintain positions involving tricky balance — such as a quadriceps stretch — for longer periods of time.
In addition to toning visible muscles like pectorals, and quads, swimming also helps improve the most important muscle in our bodies, the heart.
Because swimming is an aerobic exercise, it serves to strengthen the heart, not only helping it to become larger, but making it more efficient in pumping — which leads to better blood flow throughout your body. Research also shows that aerobic exercise can combat the body’s inflammatory response as well — a key link in the chain that can lead to heart disease [source: Columbia University Medical Center].
If that’s not enough to get you moving in the pool, the American Heart Association reports that just 30 minutes of exercise per day, such as swimming, can reduce coronary heart disease in women by 30 to 40 percent. Additionally, an analysis by the Annals of Internal Medicine showed that regular aerobic exercise could reduce blood pressure [source: Bobalik].
For some time, some people thought that because water is generally cooler than our body temperatures, it would be difficult to lose weight with a water workout. Like many old ideas about exercise, this has since been revised: Swimming is now recognized as one of the biggest calorie burners around, and it’s great for keeping weight under control.
The exact number of calories you burn, of course, depends on your own physiology and the intensity with which you exercise, but as a general rule, for every 10 minutes of swimming: the breast stroke will burn 60 calories; the backstroke torches 80; the freestyle lights up 100; and the butterfly stroke incinerates an impressive 150.
To boost the calorie-burning component of swimming, consider using intervals in which you work your hardest for short bursts and then recover. One way to structure this kind of workout would be to swim 50 yards (45.7 meters) then rest for 10 seconds, then 100 yards (91.4 meters) with a 10-second rest, then 150 yards (137.1 meters) — all the way up to 300 yards (274.3 meters) with rests in between. When you reach 300 yards, reverse the pattern [source: Petterson].
Unlike exercising in the often dry air of the gym, or contending with seasonal allergies or frigid winter air, swimming provides the chance to work out in moist air, which can help reduce exercise-induced asthma symptoms.
Not only can pool workouts help you avoid asthma attacks if you’re prone to them, some studies have shown that swimming can actually improve the condition overall. According to a study published in the scholarly journal, Respirology, when a group of kids completed a six-week swimming program, they saw improvements in symptom severity, snoring, mouth-breathing, and hospitalizations and emergency room visits [source: Science Daily]. What’s more, the health benefits were still apparent a year after the swimming program had ended [source: Physorg].
Even those without asthma could benefit from swimming, say the study’s authors, as the exercise can increase lung volume and teach proper breathing techniques.
Being healthy is more about having the right ratio of cholesterol in your body than just having low amounts of the stuff in your blood. Specifically, it’s beneficial to have higher levels of “good” cholesterol (HDL) and lower levels of LDL, or “bad” cholesterol.
Swimming can get these levels in the right balance thanks to its aerobic power, which has been proven to raise HDL levels. And for every 1 percent increase in HDL cholesterol, the risk of dying from heart disease drops by 3.5 percent [source: Bobalik].
What’s more, studies have shown that aerobic exercises like swimming can also keep your endothelium in good shape. What’s your endothelium, you might wonder? It’s the thin layer of cells that lines your arteries, and it tends to lose flexibility as you age. In one study of people in their sixties who participated in aerobic exercise, however, endothelium function was found to be equal to those 30 to 40 years younger. The theory is that because aerobic exercise causes arteries to expand and contract, it keeps them fit [source: Bobalik].
When it comes to warding off diabetes, there are few prescriptions as powerful as aerobic exercise. In one study, men reduced their risk of diabetes by an average of 6 percent for every 500 calories a week they burned in aerobic exercise [source: Bobalik]. With just 30 minutes of breaststroke swimming three times per week, you could burn 900 calories — reducing your risk of contracting type 2 diabetes by over 10 percent. A study that focused on women also suggested the same benefits for the fairer sex: Vigorous exercise just once a week (like the kind derived from a robust swimming session) lowered their risk of contracting type 2 diabetes by 16 percent over inactive women [source: Bobalik].
And, if you already have type 1 diabetes, the aerobic benefits of swimming can be particularly helpful, as this type of exercise can increase insulin sensitivity [source: University of Maryland].
According to the American Diabetes Association, diabetics should get 150 minutes per week, spread across at least three days per week, of moderate-intensity physical activity like swimming to aid glycemic control.
William Wilson wrote in the 1883 book, “The Swimming Instructor”: “The experienced swimmer, when in the water, may be classed among the happiest of mortals in the happiest of moods, and in the most complete enjoyment of the happiest of exercises.”
Wilson probably didn’t know this in the 19th century, but all that happiness was likely due to the release of feel-good chemicals known as endorphins — one of swimming’s most pleasant side effects. In addition to a natural high, swimming can also evoke the relaxation response the same way yoga works on the body. This is due in large part to the constant stretching and relaxing of your muscles combined with deep rhythmic breathing. Swimming is also a meditative exercise, with the sound of your own breathing and the splash of the water acting as a mantra of sorts that can help you “drown out” all other distractions.
Aside from the metaphysical benefits of swimming, research has shown that it can actually change the brain for the better through a process known as hippocampal neurogenesis, in which the brain replaces cells lost through stress [source: Borchard].
If the previous nine reasons weren’t enough to convince you of the health benefits of swimming, perhaps this one will: It can make you live longer.
Actually, we’re not promising Aquaman-like immortality, but it seems that swimming can at least help you. Researchers at the University of South Carolina followed 40,547 men, aged 20 to 90, for 32 years and discovered that those who swam had a 50 percent lower death rate than runners, walkers or men who got no exercise. The study authors concluded that the same benefits would be received by aqua-women as well as men [source: Prevention].