Apollo is looking fit and healthy, but how much weight can his back comfortably carry?
Planning a long ride without a pack horse is a logistical challenge, but not impossible. If it could be done by Frank Heath in the 1920's, it can certainly be done now with all the advanced "ultralight" gear that's available.
In essence, packing for this ride is very much like packing for a backpacking trip. The gear should be as light and compact as possible, for the long term comfort and health of horse's back instead of the person's.
The biggest difference for a long ride is the addition of horse gear: saddle, picket line, hobbles, feed, water, grooming kit, etc. In the packing and outfitting world, too, there have been advances in gear weight and durability.
For my long ride, I will usually be travelling through semi-populated and populated areas, so I will not need to carry as much food for myself or Apollo, or as much water, as some rural routes would require.
The usual question is "how much can a horse carry?" In reality, it is not that simple. A horse can carry a lot of weight for a short time, just as a weight lifter can press a large barbell for a workout session and an even larger weight for one clean and press in a competition.
In addition to the time factor, the rider must also take into account "live weight" - the weight of the rider - versus "dead weight" - the weight of saddle and bags. Live weight (when the rider is experienced) is less strenuous for the horse to carry, because it moves in tandem with the horse's movements like an extra appendage.
For longer distances, the rule of thumb is that a horse should not carry more than 20% of its body weight when considering all weight (rider, saddle, and gear). For a 1000 lb horse, which is approximately what Apollo weighs, this would mean 200 lbs.
However, this is not a fixed number. As he grows stronger, he could be able to support more. If he gets tired, he will be able to carry less.
On such a long journey as ours, every pound will matter. Even if he can carry 200 lbs doesn't mean I will add as much gear as I can until I reach that amount! The less packed, the better. The solution is ultralight gear and simple living.