Labradors are heavy dogs. They also tend to be laid back and most love to get their snooze time. Over time, you might begin to see red rough areas on the elbows. It's not at all uncommon for Labradors to get elbow calluses. It's nothing to be concerned about. I recommend getting Bag Balm and putting that on the elbows to keep the area soft. Most of the time though, the calluses will turn grey and will thicken no matter what you do.
If you are showing your dog, you can use cosmetic methods such as chalk to cover up the callus. However, I do think that Labradors should be shown naturally and without a bunch of froo-froo stuff done to them. Handlers will inevitably chalk, blow dry, clip, trim and generally do all kinds of things to these sporting dogs. I don't like to see Labradors all clipped with whiskers trimmed. It's just my preference since I think that they should be just given a brief brushing to knock the dust off and then presented in the ring. I don't like smelly dogs though so a bit of Listerine mixed with water will do the trick to freshen them up and cut the odor. Labradors don't need to be bathed often but regular brushing will keep their dander down and help get rid of old hair that can start to smell.