I have read a few sites that show the benefits of having a gym membership and I have my own personal experience on the benefits of exercising for free.

I think there are a few questions to ask before deciding:

What do you like to do?
If you like to be outdoors and the thought of being cooped up in a building is un-appealing then free exercise would probably work better for you. If you prefer tennis or swimming then a gym membership would make it a better value unless you have a city park with courts or lap lanes.

What do you have access to now?
Perhaps you live in an apartment complex that provides a weight-room and swimming pool or you live near an area that allows you to get out and walk. Find out what you can do around your neighborhood that you like for free first.

What is more convenient?
If you are more apt to work out on your way to or from work, find a gym that would be around your route to work to stop off at. Many people have been able to acquire exercise equipment from craigslist, freecycle or a ReUsIt groups for almost free and set up a work out area in a room in their house instead.
Do you prefer a group or to be alone?
To some people, being with other like-minded people inspires them to keep going. If you are someone who gets along with being with others who would be able to help you become better. Check for with parks and recreation classes, YMCA courses, Churches and schools who may offer classes for adults and kids.

What time do you plan to work out?
This is not high on the question list, but if you are a jogger at 3am, depending on your area, the safety of an all-night gym may be worth the money instead of the ‘quiet’ streets. Also, if your walls are paper thin in an apartment, may I suggest a gym instead of working out at 11pm when others in the area are trying to get to sleep and don’t want to hear you pushing out the 100th push-up.

What’s your goal?
If it is to get more physical activity then you can probably do that for free around your home. But if you are going for the state bodybuilding championships or the local marathon then a facility that has more equipment and mentors may be what you need.

Can you try it out for free?
If you are still unsure at this point, perhaps you can try out the local gym for a couple of days for free or by paying a small daily amount. If you do go for a free trial, make sure you stick to the trial only and don’t get talked into a ‘free offer’ that only comes with a year’s contract (two months free, IF you sign…)