Well… it depends!
If your horse is light in condition and possibly losing some weight and feels tired and lazy then yes, feeding more is probably the solution. Light condition and/or weight loss are both symptoms of note quite enough calories in the diet. Feeding more and increasing calorie intake should help with energy levels when being ridden.
BUT! If your horse is overweight or gaining weight, more feed is not the answer to overcoming your horse feeling tired or lazy when being ridden. This feeling/behaviour could be caused by multiple things, including just a lack of fitness or even a lack of education in the ‘go forward’ area.
But, overwhelmingly when we work with horses like this, more often than not the horse is tying up. But tying up on such a mild level that the only real symptom is this feeling of being tired and lazy when ridden.
Because changing diets to a diet suitable for a horse with tying up is simple and safe, it is worth a shot to see if your horse’s level of energy improves with a change in diet. Most horses that feel like this are warmblood or warmblood crosses or heavy horse or heavy horse crosses, which means the most likely form of tying up will be PSSM (polysaccharide storage myopathy).
If you eliminate all grain and grain by-product from the diet of a horse with PSSM and keep starch and sugar levels as low as possible, you should see an improvement in energy levels within 2 to 3 weeks (provided the horse is fit enough to do the work you are asking).
FeedXL can help you with this. You simply tick ‘Tying Up (PSSM)’ in your horses details and then FeedXL will colour code the ingredients in its database according to whether they are suitable for a horse with tying up or not.
Makes it much easier than trying to sift through the unfortunately sometimes misleading marketing information from manufacturers to work out what feed ingredients might be suitable or not.
For more information on feeding a horse that ties up, see https://feedxl.com/23-feeding-horses-that-tie-up/