By struggling, I don not mean staggering around. I mean taking shorter strides, to an extent that I can feel it. Or taking more care in the turns. At 32% of Cowboy's weight, he is more careful making a sharp turn than my bigger horses are. But I doubt anyone watching would notice.
I have never had a horse visibly struggle with a weight. And my biggest horse, the one I ride the vast majority of the time, carries 23-24% of her weight with me on her back. Trooper is at 25-26% every time I ride him, and I've never seen or felt any sign of difficulty with him, either. But since he has a lot of experience in his earlier life carrying 30-31% for 8-12 hour days, he probably thinks he has it easy here.
I guess the bottom line to me is that carrying 'excess weight' happens every time a rider gets on a horse, and that is how they earn their food. An 80 lb bale of bermuda hay currently runs me $18+. I don't feed them to stand around in a corral and look cute. Except for Cowboy. He get ridden about once a month, but earns his keep by playing the clown with the other horses.
The only scientific study I know of that suggests 20% is connected with reality is one where they had the horses in the study spend 4 months without being ridden. They then were worked for 45 minutes, with 14 days rest before the next 45 minutes of work.
"Results of this study suggest that, for lighter riding horses, a total weight (rider, saddle, other equipment) not in excess of 20% of the horse's body weight is quite acceptable and does not stress the horse."
I agree. If your horse is totally out of shape, then keeping the rider's weight down to 20% should prevent any soreness after a 45 minute ride. But then, I don't believe in riding a horse 2 times a month, for 45 minutes a ride. I would consider a horse used like that to be badly out of shape, just as I am after 4 years without regular jogging. The answer for me
, with my
body, is to get in shape - not to spend the rest of my life walking because anything else is too much work!
If I was a small female, I might feel free to think otherwise. But if I lost 20 lbs, I'd look like a pro boxer, and it isn't likely to happen. Everyone has to make the decision for their own horses. I personally start worrying at 30%...