Each year, the busiest fitness activity days, swimming or otherwise, occur on Jan. 2, 3 and 4, the result of New Year’s resolutions. Thus I need to deliver my annual message about fitness activity now so that fewer dropouts occur after the first week of the year.

Why do people break their fitness resolutions? Primarily, it’s because they have resolved to do what they can’t do. There are two aspects of doing what you CAN do instead of what you can’t.

First, no one should resolve to work out every day. Life causes too many interruptions. Fitness being a lifelong resolution, a day or two – or even a week or two – of non-activity is insignificant. Two or three days a week is something most everyone can fit into their schedule.

Second, doing what you can do means to start easy. A short walk or light resistance is enough.

Beyond doing what you can do, there are two simple principles to follow. The first is to be regular. Fitness activity should be part of your schedule, as much as brushing your teeth.

If at first you devote just a few minutes to your fitness routine, that’s fine, as long as you do it regularly so that it becomes a part of your lifestyle. Walk to get the mail or around the block. Do a pushup from your knees or against a wall. Stretch a bit.

The second principle is to be gradual. Once your body adapts to your easy routine, you can gradually increase in one of three ways. You can increase the duration of what you do – walk a little farther, add another easy exercise or more stretches.

Or you can increase the frequency of what you do – go from two times a week to three. Or you can increase the intensity of what you do – walk a little faster, push or pull against a little more resistance. You can also be gradual by doing one of these three and later adding another.

Don’t try to maximize anything. Keep it always at what you can do easily.

Because my Medicare Advantage plan now includes Silver Sneakers, I joined a gym for free last January. I worked against very light resistance at first to supplement my regular swimming activity, and it remains easy now.

But compared to my original resistances, by being regular and gradual, I’ve advanced well beyond those in less than a year. I encourage you, too, to practice what I’m preaching.

Dr. Bob Colyer of Bluffton is an actively retired college professor, coach and author of “Swim Better: A Guide to Greater Efficiency for Swimmers & Instructors,” directed primarily to non-competitors. bobcolyer@yahoo.com