Swimming is one of the most complete full-body workouts that there is, working up to 50 muscles at once, depending on the stroke. Since swimming has the added benefit of being low-impact and easy on the joints (not to mention, it’s basically got a built-in breathing exercise), swimming is the ideal workout for just about anyone, even if issues like arthritis or joint pain usually have you sitting out some workouts. Of course, water resistance works muscles completely differently than a normal workout might, so it’s important to keep some other elements of your routine intact, like lifting weights two or three times a week, for example, in order to keep them healthy and adjust to the way that water requires the body to move. That said, here is an outline of just which muscles each stroke emphasizes:
The Front Crawl
This stroke, also called “freestyle,” is a favorite of many because it generates the most force and therefore is the fastest stroke (a note to remember if you ever need to escape a shark or sea monster). It focuses primarily on the chest muscles, the lats and other back muscles, and core abdominal and oblique muscles. Of course, you’re also working on a number of limb muscles such as the quadriceps and biceps to propel yourself through the water.
The backstroke exercises a number of the same muscles as the front crawl because, if you think about it, they are very similar and only face opposite directions. Of course, though they are mechanically similar they resist water in opposite directions, too, and thus work different muscles. These include the hamstrings, the lats, calves, and abdominal groups. A good way to think about this is that the front crawl stretches the muscles flexed in the backstroke, and the backstroke stretches the muscles engaged in the front crawl.
This generally feels like the easiest stroke because there is a period during it when the swimmer is simply gliding and not engaging any muscles at all. Still, the forward sweep of the arms engages the pectorals, biceps, and deltoids, and the simultaneous push with the legs engages the gluteals, quads, and hamstrings.
This stroke, often heralded as the most difficult and Michael Phelps’s crowning achievement in 2008, is great for interval training because of its intensity (in other words, this might not be the stroke of choice for out-swimming a sea monster). It targets the chest, shoulders, back, and core, as well as the lumbar, hip and gluteal muscles during the sharp downward kick.