Le rucking, c'est marcher avec un sac lesté. Le poids ajouté rend la même marche plus exigeante. Un rucking élève la fréquence cardiaque et la consommation d'oxygène à un niveau modéré, et les jambes, le dos et le tronc travaillent plus dur qu'à vide. Il met aussi le squelette sous charge, le type de contrainte qui stimule le remodelage osseux.
L'essentiel des preuves mesurées a été recueilli chez des soldats sous sacs lourds et dans des entraînements avec gilet lesté. Un essai de 2025 a constaté qu'un gilet lesté ne ralentissait pas la perte osseuse chez des personnes au régime, de sorte que le résultat direct reste ténu. La plupart des gens peuvent commencer dès aujourd'hui avec un sac à dos de ville, quelques livres ou de l'eau, et une charge légère.
Findings & Outcomes
What It Is
Rucking is walking with weight on your back, usually a backpack loaded with plates, sand, books or water. It comes out of military training, where marching under a loaded pack is a core task.
Almost every measurement of rucking was taken on soldiers under heavy kit, not on someone adding 10 to 20 percent of bodyweight to a neighborhood walk. No controlled trial has tested recreational rucking. The figures come from two neighboring fields instead: load-carriage laboratories and weighted-vest exercise studies. Rucking sits between ordinary walking and resistance training: some of the cardiovascular return of the first, some of the loading of the second.
What It Does
Adding weight makes the same walk cost more energy. In ten trained men walking at a fixed 2.5 mph (4 km/h), military loads of about 27% and 46% of bodyweight raised the energy cost of every step. The load did not change how efficiently the legs recovered energy from stride to stride. It made the whole walk harder work.
That extra cost lifts an easy walk into moderate cardiovascular work. In soldiers carrying a pack of about a fifth of bodyweight, oxygen use rose to 58% of maximum, up from 47% unloaded. Heart rate climbed into the low-to-mid 80s percent of maximum, from about 71% on the same walk with no pack. Weighted-vest exercise builds leg strength, power and balance on top of that.
The bone evidence is weaker, and the two trials disagree. One small study that improved bone density had people jumping in a weighted vest, not walking under a pack.
A larger 2025 randomized trial had people wear a weighted vest about eight hours a day; it did not slow bone loss during weight loss.
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
How it works
Porter 27 % et 46 % du poids corporel a augmenté le coût énergétique de la marche à la même allure de 2.5 mph (4 km/h)
Lorsque dix hommes en bonne forme physique marchaient à la même vitesse en portant des sacs militaires lourds, la marche consommait significativement plus d'énergie que la même marche sans sac. Porter du poids augmente le coût énergétique de la marche, ce qui est précisément le but du rucking, bien que ces charges soient bien plus lourdes que celles qu'utiliserait un débutant.
Dix fantassins ont marché à une vitesse constante de 2.5 mph (4 km/h) sur un tapis roulant instrumenté dans trois conditions : tenue de sport légère (sans charge), équipement de combat d'environ 49 lb (22 kg) (environ 27 % du poids corporel) et équipement de marche routière d'environ 84 lb (38 kg) (environ 46 % du poids corporel). Le port de charge a significativement augmenté le coût énergétique brut absolu et net de la marche (P < 0.0001 dans les deux cas) et modifié le schéma spatio-temporel de la démarche, sans changer la récupération d'énergie du type pendule inversé ni l'efficacité locomotrice. Measured in: 10 male infantrymen recently retired from the French Foreign Legion, a fit and load-habituated group. Étude sur tapis roulant intra-sujet à une vitesse fixe avec des charges militaires très lourdes (27 % et 46 % du poids corporel), bien au-delà des dix à vingt pour cent avec lesquels un pratiquant récréatif de rucking commencerait, chez dix hommes entraînés. Elle établit la direction, à savoir que la charge augmente le coût énergétique, non l'ampleur qu'observerait un débutant avec une charge plus légère.
Who this may not transfer to:Measured only in fit young men. The energetics of load carriage are broadly similar across sexes for a given relative load, but women carry loads at a higher relative physiological cost on average and were not included here, so the exact figures should not be read across without that caveat.
The study · 1
Grenier et al., energy cost and mechanical work of walking during load carriage in soldiers · Med Sci Sports Exerc 2012;44(6):1131-1140
Un sac a augmenté la consommation d'oxygène de pointe de 47 % à 63 % du maximum et la fréquence cardiaque de 71 % à 88 %
Lorsque des soldats ajoutaient un sac, une marche qui utilisait 47 % de leur capacité aérobie est passée à environ 58 à 63 %, et leur fréquence cardiaque est montée d'environ 71 % du maximum à un niveau situé dans le haut des 80 %. Porter du poids transforme une marche facile en un travail cardiovasculaire modéré, bien que ces sacs soient bien plus lourds que ce avec quoi la plupart des gens commenceraient.
Quinze soldats ont effectué des tests de marche incrémentiels à quatre charges (0, 22, 44 ou 66 % du poids corporel). La consommation d'oxygène de pointe était significativement plus élevée avec charge que sans : 47 % du VO2max à 0 % de charge contre 58 % à 22 %, 63 % à 44 % et 61 % à 66 % (P < 0.01). La fréquence cardiaque de pointe a augmenté de la même façon : 71 % du maximum sans charge contre 83 %, 87 % et 88 % aux trois charges (P < 0.01). La vitesse de marche maximale atteignable est passée de 1.95 m/s sans charge à 1.48 m/s à la charge la plus lourde. Measured in: 15 US Army soldiers (14 men, 1 woman), mean age 22 years, tested with a modern military backpack. Des charges de 22 à 66 % du poids corporel sont bien plus lourdes que le rucking récréatif typique, et il s'agissait de jeunes soldats testés jusqu'à l'effort maximal, non à une allure récréative stable. Le constat est que la charge augmente l'intensité relative ; les pourcentages exacts sont propres à cette population et à cette plage de charges.
Who this may not transfer to:The sample was 14 men and one woman, so it is effectively a male finding. Women carry a given absolute load at a higher relative cardiovascular cost on average, so a woman would likely reach these intensity percentages at a lighter load, not a heavier one.
The study · 1
Looney et al., effects of modern military backpack loads on walking speed and cardiometabolic responses of US Army soldiers · Appl Ergon 2021;94:103395
Bone Density
Un gilet lesté porté 8 heures par jour n'a pas ralenti la perte osseuse de la hanche pendant une année de perte de poids
Des adultes âgés en perte de poids qui portaient un gilet lesté la majeure partie de la journée pendant un an ont perdu autant d'os de la hanche que ceux qui n'en portaient pas, et l'entraînement en résistance n'a pas aidé non plus. Le simple fait de porter un poids supplémentaire ne protège pas, à lui seul, l'os pendant la perte de poids.
Dans un essai randomisé de 12 mois, 150 adultes âgés obèses perdant environ 10 % de leur poids ont été assignés à une perte de poids seule, une perte de poids plus un gilet lesté porté environ 8 heures par jour (compensant environ 78 % du poids perdu), ou une perte de poids plus un entraînement en résistance progressif. La densité osseuse trabéculaire de la hanche totale a diminué dans tous les groupes (-1.2 % à -1.9 %), sans différence entre les groupes gilet et perte de poids seule (différence estimée +0.91 mg/cm3, IC à 97.5 % -0.27 à 2.09), et le gilet n'était pas inférieur à l'entraînement en résistance. Ni le gilet ni l'entraînement en résistance n'ont ralenti la perte osseuse. Measured in: 150 older adults with obesity (mean age 66, 74.7% women); 133 completed the trial. This tested a static weighted vest worn through the day during caloric restriction, not dynamic loaded walking, and it was done during active weight loss when bone loss is being driven hard. It does not rule out a benefit from loaded exercise in weight-stable people, but it does show that carrying external weight is not automatically a bone stimulus.
Who this may not transfer to:About three-quarters of participants were women, and the trial was not powered to compare the sexes, so whether men respond differently to worn load during weight loss is not answered here.
The study · 1
Beavers et al., weighted vest use or resistance exercise to offset weight loss-associated bone loss in older adults: a randomized clinical trial (INVEST in Bone Health) · JAMA Netw Open 2025;8(6):e2516772
Les sauts avec gilet lesté ont maintenu la densité osseuse de la hanche de femmes âgées sur 5 ans, tandis que les témoins en ont perdu environ 4 %
Des femmes âgées qui se sont entraînées avec un gilet lesté, avec des sauts, trois fois par semaine pendant cinq ans, ont conservé leur densité osseuse de la hanche, alors que des femmes similaires qui ne l'ont pas fait en ont perdu environ 4 %. C'est le signal positif le plus probant pour l'exercice avec charge et l'os, mais il s'agissait de sauts avec gilet, non de marche sous sac, et l'étude était minuscule.
Sur 5 ans, 9 femmes ménopausées ayant pratiqué un exercice combinant gilet lesté et sauts trois fois par semaine (32 semaines par an) ont maintenu leur densité osseuse de la hanche, avec des variations de +1.54 % au col fémoral, -0.24 % au trochanter et -0.82 % à la hanche totale. Neuf femmes témoins actives mais ne participant pas au programme ont perdu de l'os à chaque site : -4.43 %, -3.43 % et -3.80 % respectivement. Measured in: 18 postmenopausal women, mean age about 64 at baseline, drawn from a prior 9-month exercise study. Suivi longitudinal non randomisé de très petite taille (n=18) dans lequel les pratiquantes avaient choisi de poursuivre, si bien que l'auto-sélection et l'adhésion, et non la charge seule, pourraient expliquer une partie de l'écart. Le stimulus était le saut en portant un gilet lesté, non la marche sous sac, on ne peut donc supposer qu'il se transpose au rucking.
Who this may not transfer to:Measured only in postmenopausal women, the group at highest risk of bone loss and the group most bone-loading studies target. Whether the same weighted exercise holds bone in men, who lose bone more slowly, was not tested here.
The study · 1
Snow et al., long-term exercise using weighted vests prevents hip bone loss in postmenopausal women · J Gerontol A Biol Sci Med Sci 2000;55(9):M489-M491
Muscle And Strength
Nine months of weighted-vest exercise raised older women's leg strength 16 to 33% and power 13%, without changing bone
Older women who did lower-body exercise wearing a weighted vest for nine months got 16 to 33% stronger in the legs, gained a little muscle, and steadied their balance, while their bone did not change over that time. Loaded exercise builds the muscle and balance that keep people on their feet, faster than it builds bone.
In 44 women aged 50 to 75, a 9-month program of weight-bearing lower-body exercise with resistance added by a weighted vest, three times a week, improved lower-body muscle strength by 16 to 33%, muscular power by 13%, leg lean mass by 3.5% and indices of lateral postural stability compared with controls (all P < 0.05). Femoral-neck bone mass did not change significantly in either group over the 9 months. Measured in: 44 community-dwelling postmenopausal women aged 50 to 75, most estrogen-deplete. The exercise was weighted-vest squats and jumps, not walking under a pack, so it speaks to loaded exercise in general, not rucking specifically. Nine months was long enough to move strength and balance but not bone, and the sample was women only.
Who this may not transfer to:Measured only in postmenopausal women. Men were not studied, so whether the same weighted-vest program produces the same strength, power and balance gains in men is not established here, though loaded lower-body exercise raises strength across both sexes generally.
The study · 1
Shaw and Snow, weighted vest exercise improves indices of fall risk in older women · J Gerontol A Biol Sci Med Sci 1998;53(1):M53-M58
How It Works
Anatomy of the Practice
1The ruck itself
Under load, the muscles of the legs, hips, back and trunk work harder, to move the extra weight and to hold you upright and steady beneath it. The heart and lungs work harder too. A walk that felt easy no longer does.
2Over weeks
Cardiovascular fitness and the endurance of the leg and postural muscles build the way they do with any sustained aerobic and light-loading work. The tissues that carry the load (the feet, calves and lower back) adapt to it.
3Over months and longer
Under the added weight the skeleton carries more strain than an empty-handed walk puts on it. The repeatable gains measured from load carriage are cardiovascular and muscular. Whether rucking raises bone density in healthy people has not been tested directly.
Bone rebuilds in response to the strain put on it. The skeleton already meets a walk's strain every day, so an ordinary walk grows almost no new bone. A loaded pack raises that strain toward the level that prompts rebuilding. Mechanotransduction is how a weighted step converts that force into the remodeling signal.
Load-carriage studies used soldiers (young, mostly male) under packs far heavier than a beginner would carry. Weighted-vest studies used a vest worn during a workout or all day. None put a pack on a walker over real distance. The direction of every effect is steady. The exact figures were measured under conditions most readers will not match.
Ways to Do It
Rucking costs almost nothing to start: a backpack you own and something heavy to put in it. The whole skill is loading it safely and adding difficulty slowly. Start at about a tenth of your bodyweight, and add distance or weight, never both at once.
Any daypack with books or filled water bottles in it. Pack the weight high and tight against your upper back so it does not swing, and walk your usual loop. Water is useful weight, you can pour it out to lighten the load partway.
A padded hip belt shifts some load off your shoulders onto your pelvis. That is easier on the neck and upper back over distance, and lowers the shoulder-strap numbness heavy packs cause. The weight inside can still be books, sand or water.
Once a loaded walk is a habit, change one thing at a time and space the harder rucks several days apart. Add hills, pace or rougher ground before you add weight. This is where the durable fitness is built.
A pack built to carry a fixed, snug weight that will not shift turns rucking into something you can progress for years.
A sandbag or wrapped bricks taped into a snug daypack, or a length of steel in a padded sleeve high in the bag. It holds any weight you like, and a little tape or foam stops it shifting, a small project to pack well each time.
A purpose-built rucking pack with graduated steel or rubber plates that lock high and flat against your back. One purchase, and the plates lock flat so the weight never shifts. Easy to add to as you get stronger, and the easiest setup to keep up over years.
Go Deeper
- Walking: the unloaded base a ruck builds on.
- Resistance training: the better-evidenced way to load bone and add muscle.
- Osteoporosis: where loading is used on purpose, and how much stays safe when bone is fragile.
- Mechanotransduction: how cells sense and respond to mechanical load.
- Balance and falls: the balance and reaction training a loaded walk leaves out.
- Protein and muscle: the raw material the leg and trunk muscles need to adapt to the load.
Cautions For This Practice
Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
Loads over 99 lb (45 kg) drive stress fractures and nerve injury; load-carriage sessions every 10 to 14 days build tolerance
An international review of soldier load carriage found that loads that can exceed 99 lb (45 kg) produce musculoskeletal injuries (joint and ligament injuries and stress fractures) and neurological injuries such as paresthesias from strap pressure on nerves. It recommends progressive conditioning built on load-carriage sessions roughly every 10 to 14 days alongside resistance and aerobic training, and adjusting march speed, grade and terrain to change intensity, not adding weight alone. The injury evidence comes from soldiers carrying loads far heavier than recreational rucking and often over long distances under fatigue, so it overstates the hazard of a light beginner load while correctly identifying where the risk lies: too much weight, too soon, too often.Orr et al., soldier load carriage, injuries, rehabilitation and physical conditioning: an international approach
Start light and add load slowly
The injuries in load-carriage research cluster in people who add too much weight too fast. Build the load gradually. Pain that grows over successive sessions, or a suspected stress fracture, means you back off and let it settle, not push through.
Pack fit, and numbness down the arm
Weight carried on the shoulders can press the nerves that run under the strap, felt as numbness, tingling or weakness spreading down an arm or hand. If that happens, loosen and redistribute the load, move it higher and onto a hip belt, and let the feeling settle before you load up again.
Backs, knees and existing joint problems
A pack compresses the spine and adds force to the knees and hips with every step. If you have a low-back or disc problem, hip or knee osteoarthritis, or a previous injury to those joints, keep the weight light and favor flat, even ground. Get individual guidance before you build up.
Get cleared first if this is you
A load raises blood pressure and heart rate more than an unloaded walk. Talk to a doctor first if you have heart disease, uncontrolled high blood pressure, or chest pressure, unusual breathlessness or faintness on exertion. Pregnancy changes your balance and adds load you already carry. A recent abdominal or hernia repair needs the timeline a surgeon sets. Osteoporosis changes which loads are safe, though it does not rule walking out. Reduced feeling in the feet calls for well-fitted footwear and a daily skin check. A pack raises pressure on a foot that may not feel a blister forming.
Heat, feet and water
Heat troubles a rucker sooner than a walker, because the load makes the same distance harder work. Move a loaded walk to the cool end of the day, carry water, and break in your footwear before you add distance under load. [Hydration and electrolytes](/go/integrative/practice/hydration-and-electrolytes) covers the rest.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
Common Questions
Is rucking better than walking?
A loaded walk lifts oxygen use and heart rate above what an easy walk reaches, into moderate effort. What it lacks is walking's outcome data: the step-count studies follow hundreds of thousands of people for years, while rucking rests on lab measures and borrowed weighted-vest trials. Rucking makes a walk harder. It supplements the walking base; it does not replace the miles.
Does rucking build bone?
The remodeling mechanism is well described, but no trial has tested rucking itself for bone, and the weighted-vest trials disagree. If bone is the goal, resistance training has firmer, more direct evidence.
How much weight should I start with?
Light, for most people new to it: a daypack with a few pounds in it. The heaviest research packs run past 99 lb (45 kg), where the injuries appear; that is a warning, not a target. No load is too small to be worth doing. Add a few pounds to a walk you already take, and build from there.
Explore Related
Other pages this one connects to, by the evidence they share, the outcomes they touch, and the ground they cover.
All 6 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 9, 2026.
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