Should you boot your horse for exercise?

To be on the safe side it is better to boot up your horse when he is being worked whether ridden or being lunged and certainly when any poles are involved. Be aware that booting can cause your horses tendons to warm so only keep boots on when they are needed. Also make sure that the boots or wraps are fitted correctly, overly tight boots or uneven pressure could cause more problems for your horses legs, than not booting at all! 

Young or unbalanced horses have a higher likelihood of over-reaching or striking in to himself by mistake, so boots are a good idea to prevent injury.
Horses with big movements are also susceptible to over-reach injuries and a well fitting over-reach boot is a very good investment.

If you jump, your horse's ligaments and tendons are put under an immense amount of strain when landing, turning and taking off. In addition, an uneven, deep or hard surface plus a firm fixed object in the case of a cross country fence, it is not surprising that injuries are more frequent. Tendon boots and over-reach boots are a good option for jumpers to protect vulnerable ligaments whilst still allowing movement of the limb.
 

Hacking can also be problematic for your horse's legs and you should always consider the surface you are riding on and the gait you are choosing to work in.
Trotting on the road increases the concussion on your horse’s legs but be aware that trotting and cantering on a hard sun-baked or excessively muddy bridle path can cause catastrophic damage to tendons and ligaments through overstretching and tearing. A covering of long grass in the field can hide all sorts of dangers such as rabbit holes, rocks and stumps. So, consider walking new local routes on foot first and it is always a good idea to take it easy on terrain that has changed recently. If you are unsure of the footing it is better to play it safe and go slower and more carefully, than risk your precious horses legs!