I've always been curious on how others keep their barrel horses sound. I know many people long trot (including me) but I've always been curious on how often. I know some people who long trot as many as 4 days per week and long trot for 2 miles. I know others who long trot 2 times per week but long trot for 4 miles. 

My horses are sound, so that's not an issue. I've been told by some people that I'm not long trotting enough. I long trot once a week and use Marlene McRae method (1 mile trotting, 1 mile loping on one lead, 1 mile loping on another lead, 1/2 mile long trotting, 1/2 mile slow trotting).

I also understand that long trotting can also be horse specific. What might work for some horses won't work for others.

For my older horses, I long trot multiple days a week.  It is a good conditioning tool for horses that don't need much barrel work.  For my young horses, I warm them up long trotting for 5 or 10 minutes and then do whatever work I have planned for the day.

I have a horse with weak/loose stifles and she has to long trot 20 minutes a day, 6 days a week or they start catching again. Her KS issues & endless vet bills with that have left me waiting on blistering them. My other horse I just retired this year made 11 successful seasons sound doing 5 days a week, 15-20 minutes long trot. Never had any issues with him. Only reason he got retired is due to an injury from a fall on bad ground and at 21 I didn't want to rehab him for the year and make him come back at 22. He's earned his retirement. But I've always been a big believer in long trotting, unless you have a horse with SI issues. That often times makes the worse, so for them I keep it more limited. I usually start out on them 2-3 minutes each direction and work up from there based on their condition level. I'm one of those people that takes their fitness super serious and bring them on slow, rest them adequately, but also push them fairly hard. I certainly don't run one if I don't have time to ride for 4-6 days a week and they get 2-3 months of legging up from winter vacation before I'll make a run. So yeah, mine all get long trotted really well. I even used to do the 12 mile endurance races on one as something else to do every now & then, so I guess you could call me a dedicated long trotter lol