Q: So why trim hair if you want longer hair?
A: Trimming hair when growth appears to be slow or stagnant can allow hair to reach a new longer length (read the first part here!). When the cuticle layer (outside covering of the hair) is thinned down, it no longer offers as much protection to the internal cortex. The hair at the end therefore becomes a split end hot spot (see the diagram!!)
Q: How much hair should be trimmed?
A: The first trim depends on damage. All thinning ends ideally should be cut off, this could be an inch or it could be 5 inches. Naturally it is a very personal decision if the hair cut could result in a significant appearance change, in which case you can be more conservative and just do several small chops.
Q: How often should hair be trimmed?
A: After the first trim, you can choose to let the hair grow and trim as little or as much as you like. If you are interested in getting to a new longer length then logically, you have to trim less than your hair grows. If you work on the half an inch a month growth rate, then cutting half an inch every 3 to 4 months may be logical.
Q: How do I know my hair has been trimmed enough?
A: I can only give a subjective answer to this question. I would say that after a trim, if you notice many split ends soon after, then you probably did not trim enough. If you trimmed enough, your hair should not split as much or as often as before (at least this is my theory!)
What is your view on trimming? Is trimming just cutting hair or is it useful?