Gains in muscular strength and size from training tend to follow an asymptotic curve. You make rapid progress during your first six months to a year of training, about half as much progress during your second year, about half of that the third, and so on until your gains level out. The further you are from the limits of your potential the faster you will approach it, the closer you get, the slower.
The general recommendation is to increase the weight you use for an exercise by approximately five pounds or five percent, whichever is less, whenever you are able to complete a certain number of repetitions. This works very well for most exercises when you start working out, but five pounds can be way too much of an increase for exercises requiring a lighter starting weight, and it is unrealistic to expect to continue to go up five or ten pounds every couple of weeks indefinitely. Exercises with smaller starting weights require smaller weight increments, and as you become more advanced you need to progress in smaller increments, what is known as “microprogression”.
How small of a weight increase? Consider if you were able to increase the weight you use for an exercise by only one pound per week you would be lifting over fifty more pounds after only one year, and over one hundred more pounds after only two. While this is certainly possible for some compound exercises during your first few years of training, eventually even this becomes unrealistic.
A better progression increment for advanced trainees is around one half pound, or one quarter kilogram for those of you on the other side of the pond, for several reasons. It allows resistance progression at a relatively constant rate that is possible for even advanced trainees. Such a small weight increase every week or two will be barely noticeable, and makes it easier to stay close to the top of your target repetition range. Although your weights will not increase as much each time, they will increase more often, which can also be more motivating than seeing the same numbers on your chart workout after workout (although it is important to keep in mind performance on paper isn’t the same as progress).
You should start reducing your weight increments when a five pound or five percent increase in weight consistently results in your repetition count total dropping below your target range on most exercises (assuming there are no other factors negatively effecting performance). You don’t have to drop down from five pounds all the way to one half right away, though. Intermediate trainees may only need to reduce their weight increments to around two and a half pounds at first.
As a general rule, if after increasing the weight you are consistently unable to complete your lower target repetition number you should reduce your weight increments by a decreasing amount until the increase consistently puts you in at least the lower half of your target repetition count. If after increasing the weight you consistently exceed your upper target repetition number you should increase your weight increments by an increasing amount until the increase brings you down to at least the middle of your target repetition count.
There are several ways to do this. The most obvious is using fractional plates, which are usually available in one-quarter, half, three-quarters, and one pound plates, and can be put on a barbell or adjustable dumbbell or hung over the pin on a selectorized machine. These sets can be ridiculously overpriced though, costing over ten dollars per pound which is ten to twenty times the cost of most Olympic plates, and some do not fit all Olympic bars. Instead, I recommend getting eight quarter-pound washers with a two-and-one-eight inner diameter. These will fit Olympic plates and bridge the gap between two-and-a-half pound plates in half-pound increments for around half the cost of most fractional plate sets. If you’ll be taking these to the gym with you I recommend getting a letter punch set for stamping metal and putting your name or initials on them.
Another slightly cheaper option is to cut lengths of chain to the weight increment you want, which can be clipped on to spring collars or weight selector pins with a carabiner. Buy a few feet and weigh it, dividing the ounces by links to determine the links needed to get the weight you want, including the weight of the carabiner. If you plan to create several different weights you can buy carabiners in different colors to indicate the weights, or spray paint them.
If you’ve got questions about microprogression or know of a source of good, fairly priced fractional plates, please post them in the comments.