How long should we work our horses?
After bodywork sessions, I always like to give some homework to the owner, usually in the form of exercises designed to strengthen, stretch or mobilize specific areas of the horse's body. This will often include some precise work on the longeline or in-hand. The question everyone will ask is how long they should work their horse on the longe. To keep things systematic we like to pin a number of reps or minutes to each exercise because it makes things easier. But this should not be set in stone. What we need to realize is that it's not how long we do the exercise, but how well we do it.
Think of it this way. Every correct step the horse takes on the longe is a step towards strength and health. But every incorrect step they take is a step towards dysfunction and compensation. So if you spend 2 minutes longeing your horse in a balanced, healthy posture, you will be doing way more good than if you spend 15 minutes with the horse running around, unbalanced and braced through their body. If your horse is able to spend only 5 minutes in a good posture, adding 15 more minutes to your longeing session will not be beneficial.
Of course, when the horse is still learning how to find balance on the longe, it is inevitable that he will take some unbalanced steps as well. And if we call it quits every time he did that, he would never learn to rebalance himself. My rule of thumb is that as long as he can hold the healthy posture for longer than it takes for you to correct him after he falls apart on the longe, he is still benefiting from the session. So if the horse goes two circles in a balanced posture, then loses his balance for three steps, and you are able to correct him and find good posture for another two circles, he's still ok. If that's reversed, and he is spending more time being unbalanced than balanced, it is time to call it a day. That said, I would not recommend longeing your horse for more than 15-20 minutes in any case, at least while in the stages of learning good posture. When it comes to this kind of work, less is more!
Here is my all-time favorite before and after shot of a mare in rehab. On the journey from the left to right picture (about five months apart), she was never lunged for more than 20 minutes – this is how effective short sessions can be.