There are many factors to take into consideration when you have a horse returning to work. If any extended period of rest was required due to health or soundness issues, it is imperative to move forward only at the discretion of your veterinarian and closely follow any rehab schedule. Even if your horse just did lighter work over the winter, it is important to set realistic expectations and return to work gradually.
I think it’s important to have a few easy weeks under saddle for the horses to feel refreshed over the winter break, but my horses generally do not get complete time off. My older horses have a month where they are ridden every day, but not trained hard – just lots of walking and trotting. Two of my younger horses, who tend to put on weight and become unfit easily, stayed in full work. I find it’s easier for them to keep a solid base fitness as opposed to letting them get out of shape and then having to work really hard to get them fit again.
The most important thing for any horse at any age who is returning to work is to walk a lot, as it’s good for their mind and body. It doesn’t put any wear-and-tear on their bodies and most horses love to walk either in-hand or under tack.