I have a 3 year old filly and I'm jumping her 1 ft now and I've only been taking her over jumps for 1 day. I took her over poles for a while then stacked up some logs and she went right over them. It was nice but I felt she was ready to jump. I just say if there still going forward great it's ok to go higher just don't over do it. Also take in concideration of there age and structure. 1 ft may not seem like alot for my horse but she just started and she's only 3. If your horse is older than 5 I say raise the jumps. Good luck!