Your future self will thank you. 

Of course your twenties are a time to live it up, explore your options and do what you're crazy about. But they're also a time to get into the habit of, well, practicing healthy fitness habits—because doing so will ensure that you're healthier later on, according to a new German study published in the journal Psychology of Sport and Exercise. 

For the study, researchers tracked over 500 adults for over 18 years, and found that people who were healthiest in their young adult years were also healthiest over time. So we reached out to some fitness experts to find out their best tips for what 20-somethings should pay attention to. Your mission? Start doing all of these things—right now. Your future self will thank you!

The experts we spoke with: Greg Justice, an exercise physiologist and author of Mind Your Own Fitness; Ellen Breeding, an exercise physiologist at AYC Fitness in Kansas City; Irene Lewis-McCormick, certified strength and conditioning specialist and author of A Woman's Guide to Fitness & Strength. 

Fall in love with strength training

Seriously, if you're going to make one fitness habit stick, make it this one. Whether you're doing bodyweight circuit training or lifting heavy weights (or any of the variations in between), strength training is great for your overall health: it increases lean muscle mass, boosts metabolism, torches calories, eases back pain, helps you sleep, and even wards off diabetes. 

Drink more water

Sounds obvious, right? It's not. Most people still don't drink enough, regardless of how many times they read it on the interwebs. Here's a tip: Every time you check Instagram, chug some H2O. It adds up! 

Vary it up

Just because you're a runner does not mean you should run all the time—your body will hit a plateau if you do the same thing over and over again, and your workout won't be as effective. It's all about doing various cross-training activities each week. Hit the weight room for some strength-training circuits. Do yoga. Go for a grueling hike. Whatever it takes to work your body in different ways throughout the week. 

Embrace the rest day

This is huge! Do not get into the habit of working out seven days a week, or even attempting to do so. Incorporate a rest day into your routine so your body has time to recover—or else you could seriously injure yourself, or in the least experience some diminishing returns from your workouts. 

Learn proper form, and don't cheat

The key to circuit training and weight lifting is that you have to use proper form - otherwise you risk injuring yourself at worst, or not getting much out of your workout at best. So at least once, invest in a personal trainer (most gyms offer a complimentary session when you join). Use that time to ask as many questions as you can, so you have a better understanding re: what to do. And when you hit up a fitness class, no shame it and ask as many questions as you can about how to do the moves right—hey, you paid to be there! 

Switch up your running shoes

Yes, they're expensive, but you know what's more expensive? Hospital bills. In a Swedish study of recreational runners, the runners who ran every day in the same pair of shoes were more likely to suffer running-related injuries that sidelined them for at least a day. Runners who rotated between multiple pairs of shoes, however, were less injury-prone. 

Refuel properly post-workout

Your body craves a combo of carbs and protein within 30 minutes of working out. The carbs help give you energy, while the protein helps repair torn and stretched muscles. A good choice: low-fat chocolate milk—it's got a great combo of protein and carbs that replenishes your body after you sweated those very things out. 

Go to random gym classes

You know how your gym offers all those classes with scary names, like "Chisel Extreme" and "Booty Kickin' Step?" Go to them. Now's the time to try out all of your options, so you can figure out what works for you and what you're more likely to stick with down the road, when things like babies, marriage, promotions, and so on make working out a bit more complicated. 

Stretch before and after you exercise

Three to five minutes on the front end and the back end is enough—but you've gotta actually do it. Otherwise, your muscles tighten up and you're setting yourself up for injury later, especially as you get older. 

Make your workout a part of your day

You know you're going to shower, right? And at some point, you will forage for food. Same holds true for exercise—schedule it in so you don't question its existence on your calendar. It's just there, much like your 3 PM meetings and your OkCupid dates. 

Be mindful 

One of the best things you can do for your body? Pay attention to what it's trying to tell you. Practicing mindfulness can help teach you how to tune in to the things your body needs and is feeling, whether that's while you're eating ("I'm full!") or while you're working out ("this doesn't feel right"). 

Invest in good workout clothes

Research shows that when you feel confident in your appearance, that translates to your performance. 

Do either Yoga or Pilates

And do it for your posture. These classes will help you negate the potential hunchback that you may or may not be developing from sitting at your computer for, well, way longer than nature intended. 

Choose your friends wisely

Of course happy hours and weird warehouse loft parties are fun, and they're an essential part of being in your twenties. But if that's all your friends wanna do, that's not going to be super helpful when it comes to meeting your fitness goals. Be sure to also cultivate some friendships with people who are interested in being active, too—you'll be more likely to follow suit and stay motivated. 

Have fun!

Think of exercise as your time to release your pent-up energy, and have fun with it! Whether you try a hip-hop dance class, schedule a run with friends, or make a new playlist that you can't wait to use at the gym, it's all about seeing fitness as a fun way to spend your time—not a drag. Actually enjoying your fit lifestyle is what'll help you keep with it, long after your twenties are a distant vision in the rearview mirror. 

Source: Women's Health