Jumping, Impact, and Bone Density: What You Really Need to Know
When people first hear that impact is good for their bones, the usual reaction is, “Wait, isn’t impact what causes damage?”
It’s a fair question, we’re used to hearing about “low-impact exercise” as the safe option, but when it comes to bone density, your skeleton actually needs impact to stay strong. Bones are living tissue, they respond to the loads and shocks you place on them.
Scientists measure impact using ground reaction force (GRF), the amount of force transmitted through your body into the ground. Research suggests that a GRF of around three times your body weight is needed to stimulate new bone formation (Turner & Robling, 2003).
Here’s what different activities look like:
Walking: ~1.5 × body weight (Cavanagh & Lafortune, 1980)
Running: ~2.5 × (Novacheck, 1998)
Jump rope: typically between walking and running
Drop jumps / vertical rebound jumps: ~4.6–5.5 × (Umberger, 1999; Vainionpää et al., 2006)
So yes, jumping is one of the simplest ways to cross that threshold.
In one trial, postmenopausal women who performed 30 drop–rebound jumps, three times a week for six months, increased hip bone mineral density by ~1% (Vainionpää et al., 2006). That may sound small, but in bone science it’s a clinically meaningful change.
It’s also worth remembering that these numbers are averages, GRF varies depending on how experienced the mover is, the surface they’re on, their body type, and the exact way the activity is performed. For one person, brisk walking may generate more force than for another.
There’s nothing magical about a 20 cm drop jump and a rebound, researchers use standardised heights because they’re easy to measure. If structured sets and reps make sense to you, then use them. If not, what matters is gradually adding impact your body can tolerate.
If you can build yourself up so you’re skipping, hopping, or jumping in different ways a few times each week - you’re already giving your bones the kind of stimulus they need.
The exact number or height is less important than making impact a regular part of your movement diet. What matters is the principle: bones respond to impact that is sharp, novel, and progressive.
What About Trampolining?
Mini-trampolines (or rebounders) are often promoted as “bone-friendly impact.” They’re enjoyable, joint-friendly, and excellent for cardiovascular fitness, balance, and confidence. But because the trampoline bed absorbs much of the shock, the ground reaction forces are far lower than with hard-surface jumping (McArdle et al., 2015). That means trampolining on its own is unlikely to reach the ~3× body-weight threshold linked with new bone formation.
The research picture isn’t very strong. A few studies suggest that professional trampolinists may have higher bone density than their peers (Wang et al., 2013), but this may be because elite athletes also train across multiple high-impact activities.
For bone health specifically, it works best when combined with some hard-surface loading, whether that’s skipping, hopping, or jumping in everyday play.
What If You Can’t Jump?
Not everyone’s joints or confidence are ready for impact right away, walking is still infinitely better than doing nothing.
In fact, one of the fastest ways to lose bone is disuse - astronauts in zero gravity lose bone density at alarming rates because their skeletons aren’t loaded at all (LeBlanc et al., 2000).
Think of impact as a spectrum:
Walking helps maintain bone health.
Running and hopping create stronger loading signals.
Jumps, skips, and varied impacts provide the most powerful stimulus.
Start where you are and progress gradually.
Impact Isn’t the Whole Story
Impact loading mainly benefits the hip and femoral neck, the upper thigh bone where many osteoporotic fractures occur. That makes sense as when you land, much of the force travels directly through the legs and hips.
But those same forces don’t transfer as effectively to the lumbar spine. For spinal health, axial loading through lifting or resistance training is more effective (Kemmler & von Stengel, 2013; Guadalupe-Grau et al., 2009). Movements like deadlifts, weighted carries, and overhead presses place direct load through the spine and upper body in a way impact alone cannot.
So the most protective approach is a blend of both:
Impact (skipping, hopping, jumping) → strengthens the hip and femoral head.
Strength/resistance training (lifting, carries, pressing) → stimulates the spine and upper body.
Together, they create a more complete picture of bone health.
Here’s a summary:
Bones need impact as well as strength training to stay strong.
Around 3× body weight in ground reaction force is the threshold for stimulating bone growth.
There’s no single “magic” exercise, progression and variety matter most.
If jumping isn’t possible, walking is still protective.
The strongest results come from combining impact for hips with lifting for the spine.
It’s never too late to add impact - a skip here, a hop there, a game of chase, all count. Your bones are listening.
References if you’d like more:
Cavanagh PR, Lafortune MA. Ground reaction forces in distance running. J Biomech. 1980;13(5):397–406.
Guadalupe-Grau A, Fuentes T, Guerra B, Calbet JAL. Mechanical and metabolic bone loading as determinants of bone mass and strength: a review. Sports Med. 2009;39(6):439–468.
Kemmler W, von Stengel S. Exercise and osteoporosis-related fractures: perspectives and recommendations of the EFOS study group. Osteoporos Int. 2013;24(1):7–23.
LeBlanc A, et al. Bone mineral and lean tissue loss after long-duration space flight. J Musculoskelet Neuronal Interact. 2000;1(2):157–160.
McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance. 8th ed. Wolters Kluwer; 2015.
Novacheck TF. The biomechanics of running. Gait Posture. 1998;7(1):77–95.
Turner CH, Robling AG. Designing exercise regimens to increase bone strength. Exerc Sport Sci Rev. 2003;31(1):45–50.
Umberger BR. Mechanics of vertical jumping. Exerc Sport Sci Rev. 1999;27:79–84.
Vainionpää A, Korpelainen R, Vihriälä E, Rinta-Paavola A, Leppäluoto J, Jämsä T. Intensity of exercise is associated with bone density change in premenopausal women. Osteoporos Int. 2006;17(3):455–463.
Wang Q, et al. Trampoline training improves bone strength and body composition in young athletes. Eur J Appl Physiol. 2013;113(12):3251–3261.
Further Reading that might be useful
Age UK: Physical Activity Guidelines
UK Government “All Our Health” – Falls and Bone Health
Daly RM et al. (2019) - Exercise for the prevention of osteoporosis in postmenopausal women: an evidence-based review (J Bone Miner Res)
Giangregorio LM et al. (2014) - Too Fit To Fracture: exercise recommendations for individuals with osteoporosis(Osteoporos Int)
Alison Crouch - Bone-Safe Movement Resources
