More than 60 percent of adults don’t get the recommended amount of at least 30 minutes of moderate physical activity five days per week. We’ve all heard about the virtues of exercise—elevated mood, better sleep, better cardiovascular and lung health, better muscle tone, increased energy, and improved strength and stamina. And, oh yeah—weight loss. Yet, many of us still suffer from a simple lack of motivation.

But there is one simple way to keep you motivated and accountable to your fitness goals: the buddy system. That’s right, the rule we all learned in kindergarten—that a buddy can keep you on the right path—works for exercise, too. Research shows that working out with a partner ups the odds that you’ll honor your exercise commitments, making it easier to get fit and lose weight.

You and your partner keep each other accountable. If you can’t find a friend who wants to feel the burn, too, try a group class instead. Exercise classes also provide accountability; they put pressure on you to show up, even when you don’t know your fellow exercise buddies. Plus, classes start and end at a specific time, so you’ll know exactly how much exercise you’re getting. And you’ll likely push yourself a little harder than you would when working out solo.

From yoga and Pilates to spinning and kick-boxing, there are many different types and styles of group classes to choose from. Such variety can prevent boredom and will continually challenge your body. Another bonus: The presence of a trained instructor can help you achieve better form, which protects against injury, and helps keep your movements honest (great for when you start cheating on those lunges).