Hey Sara,I prefer to train by myself during the week but on Sundays I'll meet up with a [  slower ]friend for a 30 mile bike then a 5 mile run,he always comments on having to run harder when we train together.I also prefer to lift weights solo too as it takes half the time.It's taken me 30 years to get everything dialed in but it's still a time management project!Take care,

                                                                                                                                                                                                                    Mike

I've always been a solo trainer and every workout is as hard as I can go. When I was racing bicycles (Cat 1 - 60+ wins), I sometimes rode with a group, but there was usually a crash. In running, I think a group only works if the abilities are very similar (or you are being social and only the slowest person is seriously training). Today, about once a week I bike with my step-daughter. We either do intervals or she rides steady and I do intervals. I find that to be the best way for cyclists of unequal abilities to train together. A fun workout is to give the slower person a lead, say 30-60 seconds, and then chase. The interval ends when you catch them. I like to pick a head-start time that results in about 3 minute intervals; and then we soft-pedal for a couple minutes. 3 minutes hard followed by 2 minutes easy is my favorite interval workout. 2 hours of that will leave your thighs feeling very thick (and wobbly). I listen to books when riding and running (a car that is going to hit you, and one that will miss you by the normal 4 feet sound exactly the same - so I don't see a safety issue); but I haven't found an earphone setup that works for swimming with books.