I have been a member of a gym since 1977 where men and women had separate workout days. Currently, I belong to Equinox and use it where I live as well as other facilities when I travel. Equinox has everything including weight and cardio, Olympic lifting platform, pilates, yoga, spinning, 25 meter pool, basketball, aerobics studio and personal trainers. I use the gym for working the muscles that cycling does not and recovery. In the off season, I do lower body strength training. The best lower body work for cyclists, especially trackies, is Olympic lifts that feature explosive moves. However, being older, I pass on the explosive part and rely on my standing starts at the track to provide that component. I like some kettle bell work such as swings and Turkish getups.

I do a spin class on very rare occasions primarily because I prefer to ride my road or TT bike on the trainer against a specific workout. The personal trainers are okay but are expensive and in many cases, I know more than they do when it comes to strength training to match a sport in which I have an interest such as cycling. They are good for people who need instruction and motivation.

The pressure put on personal trainers to perform and get clients is immense. They are expected to sell services to members which is not easy and most of the work is in the evenings when the clients who can afford to pay want to workout.

I go to the gym frequently in the Winter when it is not possible to bike. The gym I use has a rubberized trail that zigzags with hills that is 1 mile long per lap. I was surprised to find that I lost more weight in the gym than biking, but of course biking is more fun.

I go the gym 3-5 days a week. Mostly weights with occasional yoga classes. I've found that watching the news while on the treadmill isn't so bad for winter, rainy days, etc. 150 bucks a year does sound really cheap as gyms go, but if there is little in the way of weights I'd probably look elsewhere. If you are one of those cyclists doing hundreds of miles a week on your bike, you probably don't want any additional grams of muscle to weigh you down anyway. But for all around fitness and health, it's hard to get the variety of weights, machines and other stuff at home.

I'm sick of riding outside on a road bike in winter and plan on working on my upper body using weights, take a few spin classes, run on an indoor track, riding a trainer, exploring off road terrain on my cx bike, but still riding my road bike outside a bit.
There is nothing wrong with joining a gym if it serves your purpose.

I am an example of someone who went to a gym, and lost weight, in combination with reducing my food intake. It worked for me. But the gym had a broad range of facilities, including an indoor pool, and quality aerobic equipment. It also showed me that variety does help. I continued to ride my bike outside, but the gym gave me a new insight, enough that I am interested in taking up triathlons.

Decide what you want in the gym and look for one that meets those requirements. I prefer to ride (or run) outdoors, but joined a gym (we have several new ones competing on $10/mo no-contract deals) for weights. I also take CompuTrainer classes in the winter at a facility run by an experienced cycling coach & trainer. My wife belongs to a full-service club (all sorts of indoor aerobics classes, spin, weights, tennis, pool) as do several riding buddies - It's pricey, and while I'd use the weights and maybe the spin class, I prefer the CT sessions (most of the spin class instructors are NOT cyclists so it's more like an aerobics class with pedals).

Ooooo.... CT sounds amusing. The spin class I attended a few years ago was rather odd.

I used to have a gym membership.

I now have a pair of adjustable dumbbells (Powerblock), a bench, and an Iron Gym at home. It seems that a combination of dumbbell exercises, pushups and pullups together with biking and the occasional running give me a complete workout.

The bench and the dumbbells are in the family room and I work out during TV time.

Who needs a gym?

Of course I live in Southern California where one can bike all year. If I lived elsewhere, I'd do like Machka did and get a membership for the colder months.