People love to ask me how I can workout as much as I do, but hate my response: "I love it." It is the same answer that will get anyone in shape and allow them to sustain the changes that they make. The difficult part is finding what you love.
The good and bad is that there are thousands of ways to get active, so how do you find what works for you? First, be willing to try new things and accept that you may feel silly. You should also keep in mind that you will need multiple exposures to fairly judge whether you like something; when people first try my classes, I tell them that they will hate it for the first 5-6 times. The only activity that you should not try more than once is one that is unsafe.
So where do you start?
Below are reviews of and honest advice on the most common first steps in fitness.
Gym Membership
Gyms are great for those who know what they are doing and require no accountability. For most beginners, this is not the case. You will never see results by mindlessly using machines, nor will you enjoy the workout, so you will stop going. Unfortunately, guilt will guide you to maintain the membership for a few months so that you do not look like a failed New Year's resolution and then you will cancel, having only lost money, not pounds or inches.
Group Fitness Classes
Whether as a part of a gym (be sure to ask whether fitness classes ("group ex") are included in the membership fee or separate) or in a specialty gym, classes provide comradery and structure.
Any class is only as good as its instructor, who are part knowledge and part personality. A teacher who will help you meet your goals is also one who can teach in a way that inspires you, whether that be through intimidation or encouragement. The best instructors for beginners are going to offer "modifications" or ways to make an exercise more appropriate for your fitness level; they are also going to coach on form and safety.
Even the best instructors cannot identify every concern in a class of fifty, which means that participants can easily hide in the back and get nothing from class, or worse, do things incorrectly and get injured.
Boot Camps
Boot camps can be an effective and engaging way to get into shape and a confidence booster, due to their reputation, but most are not for the beginner, unless groups are small and the instructor is a great coach. Unfortunately, many boot camp instructors are more interested in furthering a reputation for being tough, not good. Thus they are barking orders and dishing out exercises to people who are not using proper form and struggling both physically and psychologically. If participants are left to flounder, they stand to either push themselves too hard, risking injury, or simply quit.
Personal Trainer
A personal trainer is much like a group fitness instructor, but the need for both the right knowledge and personality are intensified. Clients are one-on-one with a personal trainer, and if a client is uncomfortable with their trainer, it can be miserable. Be sure to select a trainer who specializes in your goals. That does not mean that male trainers cannot effectively train females, but it does mean that you want to look at their other clients, as trainers do specialize, and no matter what they promise, not everyone is good at everything.
To find a great trainer, ask friends for a referral, or never be afraid to approach a trainer that you see and like. Another smart move is to ask a favorite group ex instructor if they also do personal training. Thus, you know his or her personality and specialties, and it will allow you to work with them more frequently through classes and personal sessions.
Putting It into a Plan
Start with a personal trainer, but find someone who is willing to educate you as you workout. Train with them consistently for six months to a year, as it will provide you with accountability and sufficient time to see changes in your body, if you are putting in the effort both while with them and on your own.
Fitness gets more interesting the further you progress into it, and, for many, consistently working out for six months will progress you to a point where you can safely take on more challenging classes. Thus armed with a knowledge of how to properly execute exercises, you can choose group ex or boot camps and have them be safe and effective.
Unfortunately, most classes lead to a plateau, so I would advise developing goals and rewards that encourage exploration outside of a gym. Your reward for working out four days per week for three months is to sign up for a 5k, which gives you a new focus for your training and a chance to try running. Keep exploring activities, and eventually, whether hiking, climbing, paddling, or biking, if you find what you love, you will want to keep doing it. At that point, it ceases to be "working out" and becomes "doing what I love."