1. Accountability and Motivation
You're more likely to schedule and follow through with workouts.
You have another person relying on you to coordinate scheduling of working out
Once that workout is scheduled, you're less likely to cancel plans, so as to not convenience your friend
When your journey is beginning to look tough, you have someone there to push you
You have someone to share your progress with
2. Competition
No one is perfect at everything
Someone will have more endurance, or be stronger, faster--healthy competition is good competition
You will push your friends, and they will push you to do and be better
3. Learn Something New
No matter how often you go to the gym, you don't know everything. PSH! I'm a personal trainer, and I learn new things from others trainer I work with and around
You'll learn how to do the same exercises from a different perspective
4. Avoid Getting into a Rut
When your routine begins to get stale, you have someone around with fresh ideas
You have that motivator to push you, even when you're tired
5. Avoid Injuries
You have an automatic spotter
You have a reps counter
You have someone who can check your form
6. More Fun When Working Out
You can do 2-person exercises
You have someone there to joke with
You have someone there to make any work out into a super fun experience
7. Get Better Results
You'll reach your goals quicker
You have someone there to continue to push you, and you'll stay consistent
8. Affordable Personal Training
If you cannot afford the costs of a 1 on 1 session with a personal trainer, a friend could lighten the load