Sometimes it's good to tell.

Learning to effectively describe can be a difficult task in writing. A character with a significant number of years behind them can simply be described as 'old'. This is simple and efficient which can get the fact out of the way so you can move on to more important things. Telling is a good way to allow the readers some artistic license in the creation of the character in they're mind. For stories that have to focus on something other than long character description go ahead and get the facts out.

'Charlie was old; his joints would start to set whenever he let them sit for a while without moving. The rust would build up and he could almost hear the creaking when he tried to move again. The pain was significant, so he attempting to keep moving as long as he was awake. Charlie finished a lot of work because of his joints.'

Telling allows the story to move on and frees up writers to write creative descriptions of something they feel is more important to the story.

Some writers disagree with telling. The mantra 'Show. Don't tell' is probably ringing in most of your ears right now as it is mine. However, long superfluous writing bores many readers. A friend of mine has mentioned his dislike for literature because he all too often will begin a story he thinks he may enjoy only to read, a few pages down, in a writers attempt to show the wonderful weather of the day: 'The clouds were buttered with sunshine.'  My friend is not a writer, but he could be your reader. If you want him or anyone else to buy and recommend your book. Avoid showing everywhere and get used to telling sometimes.