Hi! I was just watching a video from my riding lesson on Sunday, and I cringed when we started trotting lol. It looks like when I land, I’m landing very heavily onto his back. Any tips on landing softer in the saddle? Also, my trainer had me canter around in half seat but I had a lot of trouble staying up out of the saddle unless I grabbed some mane. Do my legs just need strengthening? If so, could you give me some exercises that would be good for that? Thank you! 
It helps to think of posting more of from your hips instead of from pushing yourself up from your stirrups. When you post more from the motion of your hips, I find that it tends to help keep a little bit lighter seat as well. When you are posting, remember to keep your core tight going up as well as going down. You may just be thinking of the up part of the posting, but the down part is part of it as well, not just a “plop down” motion-try to keep your seat light going down and it may help.
Doing some no-stirrup work (under your trainer’s supervision to make sure you are doing it correctly) would help a lot with strengthening your legs to give you a solid base that will help with your posting and half seat.
Heels too forward and/or pinching at the knee would be my first guess. Either or a combination of both will cut off your base of support and make upper body hard to control. In the video, where are your heels relative to hips/shoulders? Are your lower legs swinging around as you rise/fall? PS The key strength you need is CORE strength rather than legs. If your core’s not strong, your legs will start doing all sorts of (incorrect!) things to compensate.
Try posting without touching the saddle with your bum, use a neck strap so you don’t pull yourself up with his mouth. Try posting up for two, down for one also with a neck strap.
From a standing position on the ground, do lunges and squats (assuming that you have no problems with your knees). With the lunges do 10 reps with each leg leading, gradually building up to 3 sets of 10 reps each leg. When that becomes easy, add hand-held weights; start with 1 lb weights and work up gradually.
Start with 10 reps of the squats and work up to 3 sets.
You could add some jumping jacks too: 10 reps work up to 3 sets of 10.
The previous posts are much more comprehensive than this - but, in one of the first lessons ever, my instructor said to “pretend you’re going to sit on a boy’s lap”.
??? Why she would tell a preschooler this, I don’t know, but it’s always stuck with me.
Everyone else has good suggestions, but just chiming in to say check out the fit of your saddle.
I have been riding for decades now, and posting has never been an issue for me. I hopped on one of my trainer’s schoolies the other day, and could barely post to save my life! The twist, flap, and balance of the saddle was alllll wrong for me, I felt like I was about to topple out of it.
Got back on my horse, in my saddle, and felt like a competent rider again. :lol:
If your lower leg is forward, and you do not have a good shoulder, hip, heel alignment, posting becomes very difficult and you fall behind the motion.
Also, lead with your hips, and as said allow the horse to throw you up so you roll onto thighs, on but not gripping, the saddle.
Sometimes a neck strap is very helpful. And yes, your thighs need some strengthening.
Hi, its not your legs which are weak, its your core. Many of the above exercises would increase your core strength. When you say you had a hard time doing a half seat it is because your stomach/abs and back muscles are weak. You can do yoga to get stronger off the horse, and on the horse ride without stirrups and in a half seat arms out like an airplane as well as the many other suggestions here. Good luck. You’ll improve3.
thanks everyone 
I will try out these suggestions
[QUOTE=3chestnuts;7606244]
The previous posts are much more comprehensive than this - but, in one of the first lessons ever, my instructor said to “pretend you’re going to sit on a boy’s lap”.
??? Why she would tell a preschooler this, I don’t know, but it’s always stuck with me.[/QUOTE]
LOL, this will definitely stick with me. But the fact that she said that to a preschooler is strange, but hey whatever works
Could be the saddle, could be the length of your irons (especially since you say you have trouble getting into two point). Probably also strength. Realize too that posting doesn’t have to throw you super high out of the saddle. You really should only be a couple inches or so above your seat if you are letting your horse’s stride lift you up. Its then up to your core/hips to control that “loft” you get and stay with the horse’s motion. You can’t just plop on the the down-its a lot of controlled movement.
If you haven’t read Sally Swift’s Centered Riding. That book helped me a lot with visualization, and engaging the correct riding muscles/creating more body/muscle awareness.
I recommend lunge lessons so you can work on your seat and posting without worrying about steering or what you are doing with your hands. Posting should be a quick down but not really slapping yourself into the saddle. Also Pilates and yoga will help strengthen your core, so you can better perform all of the ideas suggested above.
[QUOTE=Posting Trot;7606220]
From a standing position on the ground, do lunges and squats (assuming that you have no problems with your knees). With the lunges do 10 reps with each leg leading, gradually building up to 3 sets of 10 reps each leg. When that becomes easy, add hand-held weights; start with 1 lb weights and work up gradually.
Start with 10 reps of the squats and work up to 3 sets.
You could add some jumping jacks too: 10 reps work up to 3 sets of 10.[/QUOTE]
Leg lifts, flutter kicks and hello dolly’s are good non weight bearing alternatives to the above torture. Plain old practice helps too.
