This is the time of year when many people turn their thoughts toward physical fitness, some for the first time. Many options are available, and anytime there are many options, there will be a certain amount of confusion. I shall attempt to help you order your thinking regarding fitness programs, and help you decide how you'd like to approach the problem of getting in better shape than you are now.
Physical activity is what The American Heart Association wants you to get some of each week. "Physical activity is anything that makes you move your body and burn calories" -- the quote from their website regarding what they consider to be necessary for continued physical existence. Essentially, not sitting or lying down is physical activity. But even elderly people can take a more productive approach to their physical existence than mere movement for an arbitrarily recommended period of time.
Physical fitness is a related concept. Defined by Kilgore and me in 2006 in the Journal of Exercise Physiology Online [9(1):1-10]:
"Possession of adequate levels of strength, endurance, and mobility to provide for successful participation in occupational effort, recreational pursuits, familial obligation, and that is consistent with a functional phenotypic expression of the human genotype."
This definition is certainly an improvement upon previous attempts to quantify the concept, in that it is both a framework that remains relevant throughout a lifespan, and a definition based on evolutionary reasoning, i.e., why it is necessary to be fit from a genetic standpoint. The optimum expression of the human genotype is, by this definition, a fit human, and this is satisfying at many levels.
Moving on up the ladder, Exercise is physical activity performed for the effect it produces today -- right now. Each workout is performed for the purpose of producing a stress that satisfies the immediate needs of the exerciser: burning some calories, getting hot, sweaty, and out of breath, pumping up the biceps, stretching -- just punching the physical clock. Exercise is physical activity done for its own sake, either during the workout or immediately after it's through. Exercise may well involve doing exactly the same thing every time you do it, as long as it accomplishes the task of making you feel like you to want to feel while you're doing it.
But for athletes and people with a definite performance objective in mind, Training is necessary. In this context, Training is physical activity performed for the purpose of satisfying a long-term performance goal, and is therefore about the process instead of the workouts themselves. And since the process must generate a definable result at a point in time removed from each workout, the process must be planned to produce this result. Training may also be the best way to achieve the goals that many people seek through Exercise.
Running a marathon, lifting in a weightlifting meet, or competing in any demanding sport requires a specific type of physical adaptation for that activity. Completing a marathon and lifting weights for a single heavy effort are very different physical tasks, and you can't be very good at both -- at least not at the same time. Long-term improvement for a specific purpose is the objective of Training, and this requires both time and a willingness to displace the feeling of having achieved a goal until the achievement has actually occurred.
Most people are not competitive athletes, do not see themselves as competitive athletes, and have no definable objective other than losing some weight and being "in shape," which is similar to being physically fit without all the discussion of phenotypes and genetics. So most people are perfectly satisfied with Exercising, and Exercise is all most people actually need, especially if their goal is just to get in shape and stay that way.
Modern corporate health clubs are designed exclusively for Exercising, Training being far less profitable. The standard industry model is 55 percent of the floor space devoted to "cardio" equipment, on which repetitive motions of various types can be performed while watching television. The remaining 45 percent of the floor space is dominated by exercise machines designed primarily for the convenience of the gym staff -- they are easy to use, easy to teach the use of, and easy to vacuum around.
Programs like P90X, CrossFit, or anything available on DVD that promises to keep your muscles "confused" are also Exercise. Any program that features random exposure to various types of physical stress cannot produce a specific physical adaptation, past a certain point that occurs relatively quickly. Their function is to burn calories, get your heart rate up, and make you sweaty and tired. They may do their job of providing Exercise quite well, and again, this may be all you need from a fitness program.
But certain people rapidly outgrow Exercise, and for them Training is the logical next step. People who respond well to the improvement that always accompanies the initial stages of any program that is adhered to faithfully quite often see the possibility of continued progress. They like the idea of taking their fitness to the next level, and in the process of discovering their physical capabilities they develop an interest in a specific aspect of their exposure to Exercise.
Whether it is distance running or strength development, these people get "hooked" by the possibilities for continued improvement that their hard work has shown them. This leads inevitably to the conclusion that the next phase of exercise must be planned to produce the specific result they have grown to value. At that point, they're Training.
Training may also be the most effective way to get the results that most people use Exercise to obtain, especially if that goal is more than just maintenance. Carefully planned activity with the specific purpose of losing weight, for instance, works better than just doing the same exercises with the same weight for the same length of time on the same days of the week for months on end. Once you set up a plan that continually increases your strength and your endurance, and that also controls your diet, you're Training, and your goal is now being prepared for, not wished for.
Wherever you might be in this process -- just starting to think about getting up out of the chair or wondering why you're not making any progress no matter how hard you try -- the correct approach to the problem involves understanding where you are along the spectrum of your physical existence, and making the correct decisions about what to do next. It may be that Exercise is all you really need, but Training may be the best answer to the problem.