Quick Answer: Rebounding is low-impact because the mat absorbs the landing - but only if you land through the whole foot with a soft knee and a stable trunk. The most common problems are landing on the toes, letting the lower back arch on every rebound, and bouncing higher than control allows. Keep the bounce low, land mid-foot, keep a slight forward hinge at the hip, and stop the set when the landings get loud.

Twenty minutes on a rebounder should leave you pleasantly worked. It should not leave your lower back aching for two days.

Seven things usually explain the difference.

1. Bouncing too high

The benefit comes from the change in acceleration at the bottom of the bounce, not from the height of the top. A low controlled bounce delivers the stimulus with a fraction of the load.

Height reduces control, and a landing you cannot control is one your joints absorb rather than your muscles.

A health bounce - feet barely leaving the mat - is a legitimate full session and is what most rebounding protocols actually specify.

Keep the feet close to the mat for most of the work, adding height only in short deliberate intervals.

And a bounce so high the mat bottoms out is the worst case of all, since the mat stops absorbing and you take the full impact through the frame.

2. Landing on the toes

The mat can only absorb what you give it, and a toe landing loads the calf and Achilles rather than distributing through the foot.

Land through the whole foot with the heel making contact or coming very close to it.

Toe landing is the single most common cause of calf soreness after a rebounder session, and it is also what makes landings loud.

It changes trunk position too, pitching you forward and encouraging the lower back to compensate.

Watch for it returning as you fatigue, because toe landing is the default when the calves stop absorbing properly.

And check the sound. A quiet session is a well-landed session; louder means you have started landing on the forefoot.

3. Letting the lower back arch

Every rebound sends force up through the spine, and an arched lumbar spine at the moment of impact concentrates that force into the facet joints.

Keep a slight forward hinge at the hip and a gently engaged abdominal wall, so the trunk stays stacked.

Ribs down, not flared. A flared rib cage is the visible sign of the arch, and correcting the ribs corrects the back.

This is where most rebounder back pain originates, and it is entirely technique rather than an inherent property of the equipment.

Arms overhead is the most provocative position for this, because raising the arms tends to flare the ribs and extend the spine. Add arm work only once the trunk position is stable.

And if your back is aching afterwards, film ten seconds of yourself from the side. The arch is unmistakable on video and almost invisible from the inside.

4. Holding the breath

Rhythmic breathing matters more on a rebounder than in most formats, because the movement is continuous and the trunk has to stay stable throughout.

Breath-holding raises intra-abdominal pressure repeatedly, which is not ideal for anyone with pelvic floor considerations - and rebounding is a high-repetition activity.

Breathe in rhythm with the bounce rather than trying to breathe deeply on a fixed count.

If you cannot hold a conversation, the intensity is above where you should be learning technique.

Pelvic floor considerations are real here. Leaking during rebounding indicates the load exceeds current capacity - reduce the bounce height and consider a pelvic health physiotherapy assessment. This is general information, not medical advice.

And the knack - a gentle pelvic floor contraction before impact-heavy intervals - is worth learning for anyone who has these considerations.

5. Skipping the warm-up and 6. going too long, too soon

The rebounder feels easy, so people skip warming up entirely. Ankles, calves and hips all need preparing, and cold calves in a bouncing format is exactly the wrong combination.

Two to three minutes of gentle bouncing without leaving the mat is a sufficient warm-up and it costs nothing.

Start at 10 minutes, not 30. The novelty of the stimulus catches out people who are otherwise fit, and the soreness arrives at 48 hours.

Progress by five minutes per week, which is unglamorous and works.

Three sessions a week is a good starting frequency, with a day between.

And treat the first two weeks as adaptation rather than training. Ankles, feet and the small stabilisers around them are doing unfamiliar work.

7. Using a rebounder that is too soft, too small or too cheap - plus a mini FAQ

A mat that bottoms out is worse than a firmer one, because bottoming out removes the entire benefit of the format.

Bungee-corded models are generally softer and quieter than spring models, and are usually easier on the joints.

Check the weight rating and buy above your weight, since the mat behaviour changes substantially near the rating.

A stability bar is a reasonable option for anyone new to the format or working on balance, and it is not a beginner marker.

Diameter matters for comfort - a larger mat gives more margin for landing position and feels considerably more secure.

How long should a rebounder session be?

Start at 10 minutes and add five per week. Twenty to thirty minutes is a solid regular session once adapted.

Is rebounding actually low-impact?

Yes, when landings are mid-foot with a soft knee - the mat absorbs a large share of the force. Toe landings and bottoming out remove that benefit.

Why does my lower back hurt after rebounding?

Almost always a lumbar arch at the moment of impact. Hinge slightly at the hip, keep the ribs down, and film yourself from the side to check.

TL;DR:

• The benefit is in the deceleration at the bottom of the bounce, not the height at the top - keep it low.
• Land through the whole foot; toe landing causes calf soreness and pitches the trunk forward.
• An arched lower back at impact is where nearly all rebounder back pain comes from - hinge slightly, ribs down.
• Breathe rhythmically; breath-holding raises intra-abdominal pressure on every rep.
• Warm up two to three minutes, start at 10 minutes, and add five minutes per week.
• A mat that bottoms out removes the entire low-impact benefit - check the weight rating.

Film ten seconds from the side. The arch is invisible from the inside and obvious on video. This is general information, not medical advice.