An expert reveals how to train for a triathlon to get in perfect shape for spring

Spring is in the air - even if it isn't technically here yet. During the winter, many of us spend too much time huddled indoors, being more sedentary than is healthy.

That's not great for our bodies or our minds, which is why so many people jump on new 'get in shape' routines as soon as nice weather hits.

Those really looking to get into shape should set a goal, something that will keep you working out regularly and force you to put a training routine on your calendar.

If you're feeling ambitious, the ideal competition may be a triathlon. The combination of running, biking, and swimming forces you to mix up your workouts, training the whole body, which will get you in great shape and could make you less vulnerable to an overuse injury.

The sport of triathlon is having a moment, says Dan Arnett, a professional coach who has competed in world championship races and Ironmans (which include a 2.4 mile swim, 112 mile bike ride, and a marathon to top things off). Participation in triathlon events has skyrocketed in recent years, and now sits at near-record levels.

Business Insider spoke with Arnett about his recommendations for beginners.

Find a race

Triathlons come in varied distances - there are very short ones and ultra-length races like the Ironman. Start with a sprint distance, Arnett says, since "that very first competition should be about you finishing."

A sprint tri consists of a 750 meter swim, a 20 kilometer bike ride, and a 5 kilometer run - distances that are within reach for anyone in reasonable shape, with a bit of training. Arnett says to give yourself at least eight weeks, though the more time you have, the better.

Pick a training plan - and stick to it

"You do not need a coach," says this professional coach who gets paid to work with triathletes. "What you need is a plan."

There are plenty of free plans online that will tell you everything you need to know, he says. Some are available on sites like BeginnerTriathlete, and there's also free software on sites like TrainingPeaks. You should schedule workouts in your calendar as if they're meetings you can't skip - otherwise it's too easy to procrastinate.

Luckily, injury rates aren't particularly high for triathletes. Since the training requires you to strengthen different parts of your body, overuse injuries are far less common than they are for single-discipline athletes. Still, don't forget to let your body rest.

By saying beginners don't need a coach, Arnett isn't trying to put himself out of business. As he explains it, the average person shouldn't do their first race shooting to end up on the winner's podium. All you need is a training schedule that will get your body ready for the competition. Investing a ton of money in an expensive coach is overkill before you know whether you like the sport.

Get only the essential equipment

The same philosophy applies to equipment, says Arnett. Triathlons tend to draw wealthy participants, with a median income of $126,000. Arnett says the moment when people are pulling off wetsuits and jumping on bikes "can look like the GDP of a small country in transition."

Looking around at some participants can make you think you need a bike worth thousands of dollars, but Arnett says he did his first few races on a mountain bike. You can use an old road bike - just make sure it's safely tuned up and give it a final test the day before your race.

You'll also need goggles and a swim cap, and Arnett recommends investing in a pair of good running shoes. It's easy to hurt yourself if you don't have the right fit, so get to a running store to be fitted.

Be prepared

Join a local training club, if you can. The camaraderie can help you push through a workout, and you'll also benefit from other members' knowledge of swimming techniques, bike repair, and race-day strategies (many people will tell you to arrive early, for example, and to bring a headlamp so you can see as you set up your gear). Training with friends and doing a occasional run with your partner - even if they aren't participating - helps, too.

I followed Arnett's advice last year, and this tip was helpful as well: If your race has an open-water swim, get as much open-water practice as possible. A murky lake or ocean full of people is very different from a pool - it can be disorienting if you don't have enough practice navigating. And if you don't feel comfortable during the swimming portion, remember that it's okay to stay at the edge or back of the pack. You've always got the bike and run segments to try to make up lost time.

Beyond that, "enjoy the hell out of your first season," Arnett says.