You’re in the gym programming the treadmill and dreading another tempo run when you happen to glance over at two people performing a bodyweight interval circuit together. Despite the intensity of their workout, they actually look like they’re having fun.

Some people are sufficiently motivated to hit the gym solo, whereas others thrive with a partner. If you’re considering pairing up for your next sweatfest, read this list of pros and cons to see if you really want to “phone a friend.” (Already got a workout buddy? Try Suffer Together: ‘Bad Partner’ MMA Workout.)

Partner Workout Pros

Motivation

Working out with another person or with a group can provide you with some needed motivation, especially on days when your energy is lagging and you’re tempted to skip out. When someone else is depending on you, you’re less likely to bag it.

Safety

Having a partner means you always have a spotter for heavy weights. So you can increase sets, reps or weight without worrying as much about injuring yourself. Running with a partner or in a group reduces the chance of your being mugged.

Time flies 

The saying “time flies when you’re having fun” is especially true when you work out. You can walk for an hour, chatting it up with your friend, and it will seem like only a few minutes have passed.

You don’t feel alone

Working out with a friend or a group allows you to develop camaraderie. It’s almost like being part of a team, since the people you choose to train with probably share a common goal.

You can push yourself further

A study of Oxford rowers showed that teams were able to raise their pain threshold when training together as opposed to solo. In the 2009 Royal Society journal Biology Letters, researchers concluded that acting as a group seemed to “ramp up the rowers.”

Partner Cons 

Getting off track

It’s easy for a partner workout to become a social gathering if you focus more on conversation than on exercise. This can sabotage your fitness goals.

Not showing up

No one likes to be stood up, and being stranded at the gym can have a negative impact, especially when your buddy flakes out on a regular basis. To avoid the problem, make sure to pick a person who is dependable.

Different levels of ability

When you’re in the zone, there’s nothing worse than having to slow down because your partner cannot keep up. You want to push yourself when you are exercising, otherwise your fitness level will not increase.

It can become irritating

Sometime, you might want to blow off steam during a workout and free your mind of distractions instead of socializing.  Having a person talking to you while you are trying to work out can sometimes be annoying if you’re trying to de-stress.