Learn rising trot: find the rhythm, change the diagonal and protect your horse's back and your own body, with clear milestones for beginners.
Why do you rise out of the saddle and sit back down in trot? The honest answer: because trot is the hardest gait to sit for most riders, and rising lets you "spring along" every second stride instead of being shaken. Trot is a two-beat gait with diagonal leg pairs, and you count exactly that beat: up, down, up, down.
Why does this matter? Researchers describe trot as the most difficult gait for most riders to sit, due to large vertical and longitudinal accelerations and quickly repeating oscillations of about 3 per second [1]. In rising trot the force peak while sitting is smaller and the peak while rising is larger than in sitting trot [1]. And novice riders on a riding simulator showed larger vertical movements and higher impact forces in the saddle than experienced riders [2]. So your goal is not gymnastics but soft, in rhythm.
A realistic expectation: rising trot is no ten-minute trick. Most people need several lessons before rhythm, diagonal and rein hand come together. Timing depends on fitness, horse and teaching; pressure doesn't help, repeatable practice does.
Ride walk and count "one, two" in the horse's rhythm. Let your hips swing along. Milestone: you can count the rhythm aloud without stumbling.
At walk, alternately rise and sit softly. Rising comes from the hip forward and up, not from pushing up on the stirrups. Milestone: you manage ten soft up-down movements without pulling on the reins.
Drive the horse on, stay seated and let the trot "run through you" for the first strides. Then rise when your hips are pushed forward. Milestone: you hit the rhythm three times in a row.
The riding-school rule of practice: you rise when the outside front leg swings forward and sit when it lands. Glance briefly at the outside shoulder, only to check. When you change rein, you change diagonal. Otherwise the horse is loaded one-sidedly on circles: if you sit on the wrong diagonal you magnify the horse's circle-induced asymmetry and it may even look lame [1].
Sit one beat longer (sit twice), then rise on the other diagonal. This loads the horse evenly on both sides, which is why the diagonal should be changed often [1]. Milestone: you change diagonal at the end of the track without losing the rhythm.
As a beginner you always practise rising trot under supervision, with a helmet and ideally on the lunge first. A wrong rhythm strains the horse's back (and yours). Don't let yourself be pushed into fast trot; a slow, regular trot is easier to hit. If your back or knees hurt, pause and talk to your instructor. Helmets are shown to protect against severe head injuries [4]. This does not replace supervised training.
When you lose the rhythm, breathe out and count aloud. Many beginners unconsciously hold their breath, which stiffens the back. Simply saying "up, down" aloud gives the brain a task and lets the body soften.
That depends on fitness, teaching and horse. Many people need a few lessons for rhythm and diagonal to sit reasonably. There is no fixed time window; a safe base is more important than a fast start.
In the riding school you rise when the outside front leg moves forward. It distributes the load more evenly on circles, and a wrong diagonal magnifies the horse's circle-induced asymmetry [1].
In rising trot you leave the saddle on every second stride, in sitting trot you stay seated all the time. In sitting trot two equal force peaks per stride act on the horse's back, up to about twice your body weight [1], so you need good trunk control.
Because you re-tense muscles every second stride. Advanced riders activate muscles more selectively and show better coordination [3]. This comes with practice and core training.
Yes, you can practise the movement of rising from the hip while standing and on a wooden horse or riding simulator. But for the feeling of the horse's rhythm you eventually need a real horse with an instructor.
Sitting Trot: Sitting Softly Instead of Bouncing