Fitness experts have long lauded the benefits of having a workout partner, someone who not only keeps you company at the gym but motivates you — and, likewise, is motivated by you — to show up even on days you don't feel like it because you know they will be looking for you.

But when it comes to picking a workout partner, few people look toward the person with whom they are partnered the rest of the time. It's common to see men working out with their guy buddies and women exercising with their female friends. Rarely, however, do we encounter couples working out together.

Asked why, we hear several reasons, most of which come down to one thing: different intensity levels. Unusual are couples in which both members exercise at the same level — be it running, lifting weights or holding difficult yoga poses. It can be hard enough to tamp down your ego at the sight of complete strangers outperforming you, but it can become personal when it's your mate.

So, the first thing you need to do is tune out everyone else. That may seem hard to do at first, but it becomes easier with practice. Focus on your own body and how it is responding. In the end, that's all that matters. You're not doing yourself any favors by, for instance, trying lift a barbell that is too heavy for you; on the contrary, doing so likely will mess up for form and, at the very least, negate the benefits of the exercise and, at worst, result in an injury.

Which brings us to the second point: Just because you can outperform someone at something doesn't mean you are an expert at it.

Jonathan Precel, a well-known strength and conditioning coach, has a knowledgeable site called Breakingmuscle.com. He recently wrote an article for his site about training as a couple. One of the hurdles, he said, is so-called "mansplaining." When a man and woman come to the gym together, the male usually assumes the role of coach.

"Remember, it's one thing to know how to lift weights, and another thing entirely to know how to instruct someone," Precel said. "Unfortunately, too many people don't understand that just because you lift doesn't mean you know what you are doing."

He suggested starting off with a personal trainer coaching the two of you. Both the knowledgeable one and the novice will learn something. Make sure the trainer gives most of the attention to the gym newbie. If you are the expert of the couple, you can even address many ego problems by asking the trainer to critique your own technique, as well.

The trainer will point out proper form for your exercises. You and your partner can have more of a shared experience by watching for common mistakes that the other one might make and — gently — warning each other if they see something wrong.

Precel also suggests praising your partner's effort rather than their accomplishments. He writes, "Praising effort discourages negative feelings when a partner misses a lift or a workout because he or she no longer feels as if they have failed. Instead, your partner feels glad to have given it a go."