A good workout partner is like gold, and like gold-seeking you may have to blow through a lot of pyrite in your search for the real thing.
Mark Twain said that “A classic is a book everyone wants to have read, but nobody wants to read.” The same can be said for exercise (especially deadlifts and squats;) everyone would like to feel as though they exercised regularly – plenty of wind and endurance, strength to move 50-pound bags of mulch into the car's trunk with no help, more firm than not to the touch, but people are often stuck on trying to Find A Better Way. If only it could be like a seaweed wrap – you show up, conk out on a table, wake up exercised.
When asked 'the best time to exercise,' like 'the best form of cardio' or 'the best workout plan,' I have opinions, but usually come back to some variation of 'whenever/whatever you'll do on the regular.' A partner, someone who you know is showing up at the appointed time to work hard, can be invaluable for this. Over and over, 'accountability' is one of the major factors in whether or not people stick with difficult resolutions. You don't want to let your buddy down, do you? DO YOU?
A good workout partner doesn't just help you load the bar or scream like George Wallace in a schoolhouse door when you're on rep 8 of a 12-rep set – they're brakes and gas; they keep you from quitting when you shouldn't, tell you to stop the set when your form goes to hell, and when you need it, makes you feel like you could run through a wall. They'll have you toying with weights that without them you'd struggle with, and make the whole thing enjoyable.
Flip side to this coin – you have to be ready to let that Workout Buddy go like Old Yeller if they're habitually late or no-shows. I strongly suggest setting the start time, and letting Buddy know (without being a jerk about it) that you're commencing then, with or without them. They get stuck in traffic? No prob, just jump in (after necessary warmups) when they get there. Ate some bad food, too comfy in bed, hungover? We'll tell them how it went.
Anybody can miss a workout, and people who go nuts when it happens need to get a grip. Arnold, when he was coming up in California and training with Franco Columbu, wasn't so much known for using workout programs of exquisite subtlety and science written by dwarves with Mithril pens, but for ferocious focus and determination put towards whatever the workout was. Well, he related in his autobiography that some days neither he nor Franco were feeling it, they'd exchange a look, and go get breakfast instead. Sometimes you do need to give up a little fish to get a bigger fish.
But is this happening more than not? When the clock hands are almost at Workout Time, do you honestly not know, if you had to bet money, whether they're gonna show or not? Yes you love them, so you must set them free. No need for a tearful breakup at y'all's favorite restaurant, just stop mentioning the workouts to them, they'll most likely be relieved, and you go back to training solo or find another partner.
We must all (portentous music comes up in background, as lights dim) make our own way in this world, and we would like those we love to share in the Good Things, of which Fitness is one. You'd like everyone to get in the lifeboat with you, but first step is, you get in the lifeboat. You take charge of your own fitness and maintain it, then you can help others find and maintain theirs.
Like most people, I had very little of a clue when I started working out. A buddy of mine had the Schwarzenegger book mentioned, which actually does have some good parts in it, but is also thick as a brick and has a lot of advanced stuff that's seductive to newcomers, but not really what they need (ditto for Muscle and Fitness.) My first year in the weight room, at college was...uninspired, besides showing me that for the most part, other people in the gym don't care what you're doing, and some of the biggest, strongest guys can be the most helpful.
I really didn't make what could be called 'gains' until I was back home for the summer, and doing a workout that centered on pushups, on a very old Persian rug that we'd had forever. Not that there's anything magical about bodyweight stuff, though it is nifty to be able to manipulate your body thru space, rather I'd just go a lot harder, not worrying about a weight falling on me or being embarrassed to fail in front of others, I guess. Plus, you can rep out with pushups, lie on the floor for ten seconds or so, then crank out three more; scary stuff with a barbell.
Was it solitude, or just a change in workout paradigms that gave the results? Some of both, and in any event I was left with the realization that the Solo Workout card was one to always have in my deck.
I can go either way these days. Having a supportive partner there seems to put me on a whole different level at times, but with my ever-changing schedule, this would be hard to do 3-4 times a week. Plus my goals are pretty well charted on, obsessive planner that I am, so it's usually like I have someone looking older my shoulder.
The old African proverb says, “If you want to go fast, go alone. If you want to go far, go together.” We all need some fast, and we all need some far. Be ready in your workout life for either.
* as long as it's not destructive, which is a whole 'nother conversation.