Jumping seems like a fairly simple form of movement. You leave the ground, land, and repeat.
Alongside gentle bouncing through the heels in Qigong, I’ve been playing around with light jumping and paying attention to how the body receives the landing.
But once you start looking at what happens inside the body, the picture becomes considerably more interesting.
Bone responds to mechanical loading. The magnitude, rate, frequency and distribution of that loading can influence the signals involved in bone adaptation.¹
We often think about exercise in terms of doing more. More repetitions, longer sessions, greater intensity.
But when I started looking into how bones respond to mechanical loading, I found that the way we load the body can matter as much as how much we load it.
This raises a broader question:
How Much Impact Does the Body Need?
1. The body responds to mechanical loading
Bone is living tissue. It continually remodels itself in response to its mechanical environment.
Specialised cells called osteocytes sit within a network of microscopic spaces and channels in the mineralised bone called the lacunar-canalicular system.
When bone experiences mechanical loading, deformation of the bone matrix drives movement of interstitial fluid through this network. The resulting mechanical forces, including fluid shear stress, can be sensed by osteocytes and converted into biochemical signals through a process called mechanotransduction. These signals help regulate osteoblasts and osteoclasts, coordinating bone formation and resorption as the skeleton adapts to its mechanical environment.¹
This helps explain why different forms of physical activity can have different effects on bone.
Walking, running, jumping, resistance training and other movements place different demands on the skeleton.
The magnitude and rate of the loading matter. So do factors such as direction, frequency, the number of loading cycles and where the load is applied.¹
There is also an interesting connection with connective tissue.
Bone itself contains a collagen-rich organic matrix, while mechanical stimulation is also involved in signalling processes associated with collagen production in tendon cells.²
That doesn’t mean every form of bouncing produces a measurable increase in collagen throughout the body.
It does suggest that mechanical loading is part of a much larger conversation between movement and tissue adaptation.
And that made me curious about the dose.
2. More loading doesn’t necessarily mean more adaptation
One of the most interesting things I came across was the idea of diminishing returns.
A review of the bone-loading literature describes how the anabolic response to mechanical loading can become saturated relatively quickly. Osteocytes appear to become temporarily less sensitive to repeated loading, meaning that continually adding more cycles doesn’t necessarily produce a proportionally larger response.³
Think of it as a diminishing-returns curve.
The first few meaningful loading events can provide a strong signal.
Further loading can still contribute, but the additional response may become progressively smaller.
This raises an important distinction:
20 minutes of continuous bouncing isn’t necessarily equivalent to 20 minutes of progressively greater bone stimulation.
The body isn’t simply counting repetitions.
It is responding to the characteristics of the mechanical signal.
3. Rest can change the response
This becomes particularly interesting when we look at research on rest between loading cycles.
In a well-known experimental study, researchers compared continuous low-magnitude loading with the same loading separated by rest periods. In animal models, inserting 10 seconds of rest between individual loading cycles produced a substantially greater bone-forming response than continuous loading.⁴
Notice the detail here:
The rest was between individual loading cycles.
It wasn’t 10 seconds of rest after a set of 10 repetitions.
A later study also found that inserting 10-second rest intervals between individual loading cycles amplified the bone response to changes in strain and cycle number in mice.⁵
Research has also explored distributing loading across separate bouts. Experimental work suggests that recovery between bouts can restore some of the bone’s sensitivity to subsequent loading.³
These studies are fascinating because they suggest that the timing of the stimulus matters.
Much of this mechanistic work comes from controlled animal models rather than people jumping around in a garden, so I wouldn’t turn a particular rest interval into a universal prescription.
I think the more useful principle is this:
The spacing of mechanical stimuli may influence how responsive bone remains to subsequent loading.
Interestingly, we’ll see something similar later in a human Qigong study where a small number of heel drops were practised several times throughout the day.
4. Forty to 100 cycles isn’t a magic number
You may come across the figure of 40–100 loading cycles when reading about bone-loading research.
This range comes from experimental work suggesting that the bone-forming response can become refractory after a relatively small number of loading cycles.
It also influenced the design of a human jumping study, where researchers limited participants to no more than 100 jumps during a session.³ ⁶
But 40 or 100 isn’t an established optimal dose.
The interesting point is that bone adaptation appears to have a non-linear relationship with repetition.
Some experimental work has found surprisingly large responses from relatively small numbers of loading cycles compared with much larger volumes.
That makes the question of how much loading is useful more interesting than simply asking how much we can tolerate.
5. What counts as a loading cycle?
This is where things get particularly interesting for jumping.
A loading cycle isn’t necessarily the same thing as one generic “rep”.
A gentle heel bounce, a deliberate heel drop, a squat jump, a single-leg landing and a depth jump involve different mechanical demands.
The force, speed, direction, muscle contribution and landing characteristics can vary considerably.
So when a study reports “40 jumps”, that number tells us something about the quantity of movement, but not everything about the mechanical stimulus experienced by the skeleton.
This is an area where recent research is particularly interesting.
A 2026 randomised controlled trial examined whether increasing drop-jump height would produce proportionally greater bone adaptation. The researchers found that increasing the prescribed height did not produce proportionally greater osteogenic responses, and individual participants experienced considerable variation in the actual mechanical loads generated by the same exercise.⁷
That is a useful reminder that the movement we prescribe and the mechanical load a person actually experiences aren’t necessarily the same thing.
6. The human jumping study
One study that really caught my attention involved 38 physically active men with low bone mass.
The participants followed either a resistance-training programme or a jumping programme for 12 months.
The jumping group trained three times per week, with at least 24 hours between sessions.
But when you look at what they actually did, the word “jumping” starts to mean something very different from casually bouncing up and down.⁶
The programme began with movements such as:
- squat jumps
- forward hops
- split-squat jumps
- lateral box push-offs
Later stages introduced movements including:
- bounding
- lateral bounding
- box jumps
- hurdle jumps
- zig-zag hops
- single-leg lateral hops
- progressive depth jumps
- jumps from a box
Participants were instructed to jump explosively.
Depth jumps and box-jump heights progressed from around 10 cm up towards 100 cm over the programme.
And the researchers used 10 seconds of rest between individual jumps.
These weren’t 100 casual little bounces.
Even some of the early exercises involved active, explosive movements, while later stages clearly introduced substantially greater impact and complexity.
After 12 months, the jumping intervention increased whole-body and lumbar-spine bone mineral density, while the resistance-training intervention also produced an increase at the total hip.⁶
The study is interesting, but the population and protocol matter.
These were physically active middle-aged men with low bone mass, and the intervention was carefully structured over a year.
So the study gives us useful information about how a deliberate jumping programme can influence bone, while leaving plenty of questions about how different forms and doses of impact might work in other people.
7. Does higher impact always produce a stronger response?
This is another area where the research becomes less straightforward than I initially expected.
It seems intuitive that jumping higher should create a stronger stimulus.
Sometimes it may.
But the relationship between impact height and bone adaptation isn’t necessarily linear.
The 2026 drop-jump study is a good example. Increasing the prescribed drop height didn’t produce proportionally greater osteogenic responses. The actual mechanical loads experienced by individuals also varied substantially even when they performed the same task.⁷
This raises a broader question:
Is the most useful measure the exercise itself, or the mechanical stimulus the exercise creates?
That is still an interesting area for research.
It also makes individual differences relevant.
A jump that feels substantial for one person may be relatively easy for another.
Body weight, strength, coordination, training history, landing mechanics and tissue tolerance can influence the forces produced.
So a useful loading stimulus probably needs to be considered in relation to the person receiving it.
8. Heel drops can create substantial loading
This is where the research becomes particularly relevant to Qigong.
A heel drop is different from both gentle bouncing and jumping.
Rather than leaving the ground, you rise onto the balls of the feet and let the heels return firmly to the floor.
When the heels contact the ground, the interaction between the body and the ground produces a ground-reaction force.
A 2019 study compared heel drops with countermovement jumps, box drops and stamping in 14 early postmenopausal women. The researchers examined mechanical loading and muscle activation rather than changes in bone density over time.⁸
This showed that a relatively small movement such as a heel drop can still create a substantial mechanical stimulus.
Another study measured heel drops directly using a force plate.
Twenty women performed the movement, producing an average peak ground-reaction force of around 4.9 times bodyweight.⁹
The researchers were interested in previously proposed osteogenic loading thresholds, although they also called for longer-term studies to establish the relationship between these forces and actual bone remodelling.
Still, I find the measurement striking.
The feet don’t have to leave the ground for the body to experience considerable mechanical loading.
It also shows how misleading the visible size of a movement can be.
A heel drop may look much gentler than a jump, yet the way the heel contacts the ground can create a relatively large force.
9. A Qigong heel-drop study
There is also some direct research involving a movement surprisingly close to the Qigong practice that started this exploration.
A 12-month randomised trial investigated a modified version of the eighth movement of the Eight Brocades in 198 postmenopausal women with osteoporosis.¹⁰
The movement involved slowly raising the arms and heels before allowing the heels to fall back to the ground, creating a light vibration through the body.
Participants practised seven repetitions at a time, three times per day.
After 12 months, the exercise-only group showed a net gain of around 1.9% in femoral-neck bone mineral density relative to the control group, alongside improvements at the lumbar spine.¹⁰
This is particularly interesting because the movement is considerably closer to Qigong heel dropping than the explosive jumping interventions we looked at earlier.
The way the practice was distributed also caught my attention.
Seven repetitions performed three times throughout the day is quite different from accumulating 21 repetitions continuously.
The study compared the exercise with control and calcium conditions rather than different exercise schedules, so the contribution of the spacing itself remains open.
But alongside the research on diminishing responsiveness and rest between loading events, it raises an interesting possibility:
A few brief encounters with impact throughout the day may provide a different mechanical signal from accumulating the same repetitions continuously.
10. So what about gentle heel bouncing?
This brings me back to the movement I originally became curious about.
Gentle heel bouncing isn’t necessarily the same thing as the heel drops used in these studies.
There may be less impact, less vertical displacement and greater absorption through the ankles and knees.
The movement is also active. Muscles contract, the body moves rhythmically and the feet repeatedly interact with the ground.
Exactly where it sits mechanically will depend on how the movement is performed.
How high do the heels rise?
How quickly do they return?
How much of the landing is absorbed through the ankles and knees?
What surface are we standing on?
Are we barefoot or wearing cushioned shoes?
These variables can substantially change the mechanical stimulus even when the movement looks similar.
This makes the transition from gentle bouncing to deliberate heel dropping particularly interesting.
At what point does a soft rhythmic bounce begin to produce a substantial skeletal loading stimulus?
And might gentler bouncing still produce other physiological effects even when the impact remains below what would normally be considered a strong osteogenic stimulus?
Those seem like interesting questions for further research.
11. What about collagen?
This was another part of the research that caught my attention.
Bone isn’t simply mineral.
It also contains an organic matrix rich in Type I collagen, which contributes to its structure and mechanical properties.¹
When mechanical loading stimulates new bone formation, osteoblasts deposit a collagen-rich extracellular matrix called osteoid, which subsequently undergoes mineralisation. Type I collagen forms the principal collagen component of this matrix.
So there is a genuine biological relationship between mechanical loading, bone formation and collagen.
This makes the Eight Brocades study particularly interesting. A heel-drop intervention produced measurable changes in bone mineral density over 12 months.¹⁰
The study measured bone mineral density rather than collagen synthesis, so it doesn’t tell us how collagen production itself changed in response to the exercise.
Mechanical stimulation can also influence connective-tissue biology elsewhere in the body, including markers associated with collagen synthesis in tendon cells.²
This raises an interesting question about how different forms of mechanical loading influence collagen-rich tissues over time.
The response may also vary with the type of tissue, location, loading pattern, magnitude and recovery.
12. What about whole-body vibration?
This also brought me to whole-body vibration.
Whole-body vibration research is interesting because externally generated mechanical oscillations can produce physiological effects, while studies have produced mixed results regarding bone mass.
Some animal studies using low-magnitude vibration have found little or no effect on bone mass, while other protocols and populations have produced different outcomes.¹
Heel bouncing isn’t the same thing as whole-body vibration.
With vibration platforms, an external device generates the oscillation. With heel bouncing, the person actively creates the movement through muscular contraction and interaction with the ground.
So I wouldn’t treat them as interchangeable.
But the comparison raises an interesting question.
Could some of the physiological effects associated with repeated mechanical oscillation also occur during gentle active bouncing?
And could a movement produce useful metabolic or circulatory effects while providing a smaller skeletal stimulus than a deliberate heel drop or more forceful jumping?
At present, those questions remain open.
A movement doesn’t necessarily have to provide a strong bone-building stimulus to have other physiological effects.
13. So what’s enough?
This is probably the question I started with.
How much impact does the body actually need?
The research doesn’t give us one simple number.
Instead, it points towards several principles.
Mechanical loading can stimulate bone adaptation.
The magnitude and rate of loading matter.
The location of the load matters.
The response can become less sensitive with repeated loading.
Rest and the distribution of loading may influence responsiveness.
A movement that looks small can still create substantial mechanical forces.
Different forms of movement produce different mechanical stimuli.
And individual people can experience very different loads from the same exercise.
That makes me think about loading less as a question of volume and more as a question of information.
A landing gives the skeleton a mechanical signal.
A change in speed changes the loading.
A change in direction changes the loading again.
Changing the way the heels contact the ground changes the stimulus.
Increasing the height or complexity of a movement changes it again.
Rest changes the timing of that stimulus.
And repeated exposure over weeks and months gives the body an opportunity to adapt.
14. Exploring a gentler approach
This is where I want to experiment rather than present a finished prescription.
For someone already comfortable with impact, jumping can provide a relatively strong mechanical stimulus.
For someone less accustomed to it, there are gentler places to begin.
Something like:
Heel raises → gentle heel bouncing → heel drops → small two-foot jumps → more dynamic jumps
Each step changes something about the mechanical signal.
A heel raise involves returning the heel to the ground under control.
Gentle bouncing introduces rhythm and repeated interaction with the ground.
A deliberate heel drop increases the landing stimulus without requiring the feet to leave the floor.
Jumping adds a flight phase and potentially greater landing forces.
From there, height, speed, direction and complexity can gradually change.
The surface and footwear matter too.
Cushioned footwear and softer surfaces can reduce the transmitted impact, while firmer surfaces and less cushioning can increase it.
How much the ankles and knees absorb the landing also changes the transmission and distribution of force through the body.
That gives us several ways to adjust the stimulus without simply adding repetitions.
For someone exploring heel drops, having a stable support nearby can also make it easier to focus on the movement rather than balance.
A simple starting point might involve a small number of gentle movements, paying attention to how the body receives them and gradually exploring greater impact according to experience, strength and tolerance.
The numbers used in research are study protocols, not scientifically established optimal doses for everyone.
That distinction matters.
The research gives us principles to work with. It doesn’t give us a magic number of heel bounces, heel drops or jumps that guarantees a particular adaptation.
What I find most interesting
The more I looked into this, the less interested I became in simply asking:
How much exercise should I do?
A more interesting question became:
What information am I giving the body through this movement?
That feels relevant beyond jumping.
Qigong has made me increasingly interested in the relationship between movement, attention and response.
A movement can be gentle while still giving the body plenty of information.
Pressure.
Balance.
Rhythm.
Breath.
Direction.
Changing levels of effort.
Attention.
And perhaps this is one of the interesting things about exploring impact in a more conscious way.
Rather than assuming that harder, longer or higher automatically means better, we can become curious about how the body responds as the stimulus changes.
There is still plenty to explore.
How much loading is useful?
How much recovery helps?
How does the response change with intensity?
How does it differ between people?
And where does gentle bouncing sit within that spectrum?
For me, that’s the interesting part.
Not simply doing more.
Learning how the body responds.
If you’d like to explore some of this movement yourself, I’ve put together a simple guide to bouncing and jumping, starting with gentler options and building from there.
Watch the bouncing and jumping guide → https://youtu.be/UPz5NOzAm38
References
1. Mancuso ME, Wilzman AR, Murdock KE, Troy KL. Effect of External Mechanical Stimuli on Human Bone: a narrative review. Progress in Biomedical Engineering. 2022.
2. Squier K, Mousavizadeh R, Damji F, Beck C, Hunt M, Scott A. In vitro collagen biomarkers in mechanically stimulated human tendon cells: a systematic review. Connective Tissue Research. 2024.
3. Gardinier JD. The Diminishing Returns of Mechanical Loading and Potential Mechanisms that Desensitize Osteocytes. Current Osteoporosis Reports. 2021.
4. Srinivasan S, Weimer DA, Agans SC, Bain SD, Gross TS. Low-magnitude mechanical loading becomes osteogenic when rest is inserted between each load cycle. Journal of Bone and Mineral Research. 2002.
5. Srinivasan S, et al. Rest-inserted loading rapidly amplifies the response of bone to small increases in strain and load cycles. Journal of Applied Physiology. 2007.
6. Hinton PS, et al. Effectiveness of resistance training or jumping-exercise to increase bone mineral density in men with low bone mass: a 12-month randomized, clinical trial. Bone. 2015.
7. Scott R, Sale C, James R, Barnett CT, Varley I. Evaluating the dose–response relationship between drop-jump height and bone adaptation: A randomized controlled trial. Bone. 2026.
8. Montgomery G, Abt G, Dobson C, Smith T, Evans W, Ditroilo M. The mechanical loading and muscle activation of four common exercises used in osteoporosis prevention for early postmenopausal women. Journal of Electromyography and Kinesiology. 2019;44:124–131.
9. Ryan CMC, Clissold TL, Winwood PW. The Osteogenic Quantification and Reliability of the Heel Drop and Press up Drop. International Journal of Science, Technology and Society. 2021;9(6):294–300.
10. Liu BX, Chen SP, Li YD, et al. The Effect of the Modified Eighth Section of Eight-Section Brocade on Osteoporosis in Postmenopausal Women: A Prospective Randomized Trial. Medicine. 2015;94(25):e991.
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