(BPT) - It’s dark. It’s cold. Heading to the pool might be the furthest thing from your mind. While summer is the time of year for playing at the beach, pool parties and outdoor water sports, the colder months are actually a great time to start swimming.

“Swimming is a low-impact exercise that depending, on the intensity of the workout, can involve multiple energy systems,” says U.S. Masters Swimming Club and Coach Services Director Bill Brenner. “Swimming improves your cardiovascular system as well as stamina and flexibility. It is a popular form of exercise for weight loss and weight control due to the high caloric consumption associated with the activity.”

Swimming is the form of exercise most adults would choose to do if given the opportunity, according to research by the Sporting Goods Manufacturers Association . “If you ask 10 adults if you could do one exercise for an hour with maximum benefits and minimal risk for injury the majority would pick swimming,” says Brenner. “This is true even for those who can’t swim a length of the pool, because 37 percent of adults can’t.”

Rebecca Sato, 44, of Austin, Texas, used to be a non-swimmer two years ago. “I was totally sedentary and had 70 pounds to lose,” Sato recalls. “In the course of losing weight and getting into shape, I needed to find something I enjoyed doing.”

She learned to swim at Life Time, The Healthy Way of Life Company, and while she was at it, enrolled her two sons, now 5 and 9, into lessons so they could learn to swim, too. “I didn’t want them to grow up like me,” Sato says. “I wanted something athletic in their life and swimming, especially for little kids, is non-negotiable. Kids need to be able to swim because otherwise they’re not safe.”

Drowning is the No. 1 cause of death for children younger than 5. Even the American Academy of Pediatrics revised its position statement in May of 2010 to encourage children as young as 1 to start lessons to help prevent drowning. But depositing your child into a swim lesson at the start of summer may not provide enough time to acquire the skills they need before the outdoor pools open.

“The average child needs approximately 30 hours of swimming lessons before they can swim consistently and confidently 25 meters of a pool,” says Alicia Kockler, senior national aquatics manager at Life Time.

Kockler says that swimming a length of a pool indicates that a swimmer has the proficiency level and stamina to survive a dangerous situation in the water - he could survive long enough to either reach safety or for help to arrive.

“Currently less than 40 percent of children 18 and younger can swim the length of a pool,” Kockler says.

Children who don’t learn how to swim become adults who don’t know how to swim. Sato, having been one of those non-swimmers, has since started teaching swimming to adults at the same Life Time where she learned to swim.

“I see a lot of adults who think it’s too late,” Sato says. “Learning to swim as an adult is totally possible with some work.” Swimming skills are wired in for adults who learn as children, which is why, she adds, children’s swimming lessons are so important. “Swimming will pull your body in different directions — healthy directions — the direction it needs to go.”

Even if someone has adequate swim skills by summer’s end, doesn’t mean they can hang on to them the following summer without practice. Get into the pool again after months on dry land and you may feel like you’re starting over.

“When kids only swim in the summer, they typically regress a skill level by the time they start up again,” Kockler says. “This means that all that hard work over the summer is partially lost. Swimming regularly, ideally weekly, over the course of the year will provide far greater skill development in a year’s time than a condensed schedule of the equivalent amount of hours of swim instruction over the summer.”

Going to the pool to practice doesn't always mean swimming drills and working on technique, Kockler adds. “Playing in the pool builds strength, stamina and skills. What’s more, children whose parents join them in the water and share in the enjoyment tend to learn faster.”

So jump in now. The air outside might be frightful, but the water feels just right.