What is rucking? What walking with weight does for you, and what it does not

Anyone who walks to work with a laptop, a packed lunch and a change of clothes on their back has been rucking for years without calling it anything. What is new is that the word has become a training trend, with dedicated packs, weight plates and promises of fat loss, a stronger back and tougher bones.

Some of those promises hold up. Others rest on military research on young soldiers, or on studies that show something other than what is claimed. This guide covers what the weight actually does to your walk, what the research has and has not shown, how heavy to start and where it tends to hurt. At the end: how rucking fits into a week that already has strength and cardio in it.

What rucking is, and what it is not

The word comes from rucksack. Marching under load has been a basic military drill for a very long time. The civilian version is simpler: a backpack with some weight in it, a walk at a brisk pace and a route you choose yourself.

Three things set rucking apart from most other cardio:

• There is no flight phase. You always have at least one foot on the ground, so the load on each step is far lower than in running, even with weight on your back.
• You set the intensity with the weight, the hill or the pace. An ordinary walk quickly becomes too easy once you are fit. Rucking gives you more dials to turn.
• Your body carries its own weight plus the load. That makes rucking weight-bearing exercise, unlike cycling and swimming. What that means for your bones is more complicated than it sounds. More on that below.

Rucking is not run commuting with a backpack, though. Running under load is a different stress, with more impact and more demand on tendons and feet. It has its own guide: run commuting covers how heavy the bag can be when you run and how to build up.

What the weight does to your walk

The most widely used model for the energy cost of walking with a load is the Pandolf equation. US military researchers developed it in 1977. It estimates metabolic rate in watts from body mass, load, speed, gradient and terrain. We used it to run the numbers for an 80 kg person walking at 4.8 km/h (3 mph) on tarmac.

These figures are calculated, not measured. The model is old, and later research has shown that it underestimates the cost of modern military loads. But it tells you about the proportions, and the proportions are what matter here.

The hill beats the weight

The same equation shows something rarely said about rucking. Add a 5% gradient, which is an entirely ordinary hill, and the energy cost rises by more than 50%. That is with no load at all. With 10 kg on the hill, it comes to just over 70% more than the flat walk without a pack.

It works the other way too. Put on 10 kg and slow down to 4 km/h, and the model puts you at about 14% lower energy cost than an unloaded walk at 4.8 km/h. That happens a lot, because the weight feels heavy and your legs instinctively ease off. At that point the weight has cancelled out its own benefit.

The same pattern shows up in the Compendium of Physical Activities, which lists energy cost in METs, meaning multiples of your resting rate:

What the research has actually shown

This is where it gets thin. There is no controlled trial in which adults in midlife rucked over a long period and were compared with a group that did not. Most of the research on loaded walking comes from the military and involves young soldiers carrying far heavier loads than any recreational walker. The closest thing to everyday life is research on weighted vests, and it is worth reading carefully.

The weighted vest that did not protect the hip

The largest randomised trial we found was published in JAMA Network Open in 2025. Researchers randomised 150 older adults with obesity, average age 66, to three groups for a year. Everyone lost weight through diet. One group also wore a weighted vest for eight hours a day, with the vest getting heavier as they lost body weight. A third group did supervised strength training three times a week.

All three groups lost roughly the same amount, 9% to 11% of body weight. Hip bone density fell in every group. The researchers concluded that neither the weighted vest nor the strength training was able to offset the bone loss at the hip that came with weight loss.

Two things need saying about that trial. It tested a vest worn through the day to replace lost body weight, not training sessions with a backpack. And the participants averaged 66, had obesity and were in the middle of planned weight loss. But it is the best evidence we found, and it gives no support to the claim that weight on your body protects your bones in itself.

The small studies that get quoted

• Weighted vest plus jumping, five years. A US study from 2000 followed 18 postmenopausal women. The nine who had trained with weighted vests and jumping three times a week lost less hip bone density than the nine who had not: 0.8% versus 3.8%. The follow-up was not randomised, and the effect came from the jumping combined with the vest, not from walking.
• Walking in a weighted vest, six weeks. A 2013 study randomised 36 women with osteoporosis to three groups. Two of the groups walked on a treadmill for 30 minutes three times a week, one of them wearing a vest of 4% to 8% of body weight. The third was a control group. Both walking groups improved markers of bone turnover. The vest group improved balance more. Bone density was not measured.
• Ordinary walking. A 2008 meta-analysis of studies in postmenopausal women found that walking had no significant effect on spine bone density. At the femoral neck there was a small effect that sat right on the edge of statistical significance. The authors wrote that exercise giving more targeted skeletal loading is probably needed.

Read together, the evidence says roughly this: walking with weight is better for your bones than not moving, and probably better than cycling alone, which the guide to cycling and strength training covers. But no study has shown that rucking builds bone in adults. The loading that does have support comes from impact, jumping and heavy strength training.

Does rucking count as strength training?

Usually not. The WHO recommendation for adults is 150 to 300 minutes of moderate activity a week, plus muscle-strengthening work for all the major muscle groups on at least two days a week. Rucking covers the first part easily.

The second part is harder. The NHS gives carrying heavy shopping bags as an example of a strengthening activity, but adds that you should work to the point where you need a short rest before you can carry on. A walk with 5 kg on your back rarely gets your legs there. Your back and trunk do work, but it is endurance work, not the heavy signal that builds strength. So rucking belongs alongside your strength sessions, not instead of them. Two short sessions at home are enough. The setup is in the guide to strength training at home after 40.

How heavy should you start?

The honest answer: there is no research-based starting weight for recreational walkers. The numbers that circulate come from equipment companies and military experience. The US backpack maker that popularised rucking advises starting with 10 to 25 pounds (about 4.5 to 11 kg), adding 5 pounds (just over 2 kg) a week and never carrying more than a third of your body weight. That last rule comes from a historical analysis of soldiers' loads, not from any study of healthy 45-year-olds.

The only researched dose anywhere close to everyday life is 4% to 8% of body weight, from the osteoporosis study above. For an 80 kg person, that is 3 to 6 kg.

So we start at the lower end and follow the same principle as every other progression on this site: change one thing at a time and let it settle for two weeks. Weight, time and hills are three different loads. Never increase two at once.

Add a third session a week as a separate step once the hill has settled in. The ladder is a practical sequence, not a published programme. Most people who want fitness and a more resilient body never need to go above about 10 kg. That is our judgement, not a research finding. If you want to make the session harder after that, a hill is almost always a better choice than more weight, for the reasons in the section on hills above.

The pack: backpack or vest

How the load sits matters a lot too, not just how much it weighs. The military research is clearest on exactly this point.

• Close to the body and high. A load whose centre of mass sits close to your own gives the lowest energy cost and lets you walk more upright, much as you would without a pack. Heavy backpacks make you lean forward. Pack the heaviest items high and tight against your back.
• Use a hip belt when there is one. A review of military load carriage states that hip belts should be used whenever possible, because they reduce pressure on the shoulders. Part of the load moves from your shoulders to your hips.
• Front and back. A load split between chest and back costs less energy than the same load on your back, and changes your gait less. In a study with nine participants, walkers used 5% less oxygen on average carrying a pack with front pockets than carrying a traditional rucksack. That is the case for a weighted vest. We have not found any study comparing a commercial weighted vest with a backpack in recreational walkers.
• Nothing that bounces. Plates or a water bottle knocking against your lower back with every step chafe and pull you off balance. Fill the gaps so the load stays still.

An ordinary backpack with a chest strap and hip belt and a weight wrapped in a towel will take you a long way. You do not need special gear to get started.

Where it tends to hurt

The military's long experience of marching under load produces a list worth knowing, even though a recreational walker's loads are much lighter. The most common injuries are foot blisters, stress fractures, back strains, pain under the forefoot, knee pain and something called rucksack palsy.

That last one is a compression or stretch injury to the network of nerves around the shoulder, caused by the shoulder straps. Symptoms include numbness, tingling, cramping and weakness in the arm. The suspected risk factors are heavier loads, longer distances and a badly distributed load. What protects you is a hip belt, wide and well-padded straps, less weight and a symmetrical load.

With 5 kg in your pack, the risk of the serious injuries is small. But the mechanism is the same, which is why the hip belt and the slow build-up are in the advice above. If your neck and shoulders take the most strain, strengthening exactly those areas helps. The exercises are in the guide to back and shoulder pain from a desk job.

How rucking fits into your week

Rucking works best as the easy cardio in your week, the same slot as a walk or an easy bike ride. It is moderate intensity for most people, it costs little recovery and you can do it on the same day as a strength session. A week might look like this:

• Two strength sessions covering legs, hips and upper body. These are what build muscle and give your bones heavy loading.
• Two or three rucks of 30 to 45 minutes, ideally built into a trip you are making anyway: to work, to the shops, to football training.
• Running or cycling if you want them, but then look at the total volume. Three kinds of cardio in the same week is more load than it sounds.

If you are combining strength and endurance work, the full logic for where to put the sessions is in the guide to strength training and running. Rucking interferes with strength training less than running does, because it has none of the braking impact of the running stride.

A missed session is data, not a failure. That applies to rucking as much as to anything else. If you skip the weighted walk one week, then it is a walk without the weight, or no walk at all. Nothing needs to be made up.

Who should be careful

The advice on this page is for adults who are broadly healthy. Some groups need to think differently:

• Osteoporosis with vertebral fractures. The UK consensus statement on exercise for osteoporosis says that people who have had a vertebral fracture or multiple low-trauma fractures should usually keep to impact equivalent to brisk walking. It advises against a high degree of spinal flexion, especially with weight. So weight on your back should be tried together with a physiotherapist, not on your own.
• Risk of falls. The same statement says that people at increased risk of falling should build strength and balance before adding brisk walking. A backpack makes a fall harder.
• Pregnancy, heart disease or a current injury. We have not found any official guidance on loaded walking for these groups. That in itself is a reason to talk to your midwife, doctor or physiotherapist before putting weight on your back.

When to seek care

Frequently asked questions

What is rucking?

Rucking is walking with weight in a backpack or a weighted vest. The word comes from rucksack and from the military practice of marching under load. It makes an ordinary walk harder per minute without turning it into a run, because you always have at least one foot on the ground. It counts as weight-bearing cardio and sits at moderate intensity for most people. There is no controlled trial of rucking as a form of exercise for recreational walkers. Most of what is said about it rests on military research and on studies of weighted vests.

How much weight should a beginner ruck with?

There is no research-based starting weight. Equipment companies often recommend 10 to 25 pounds (about 4.5 to 11 kg) to begin with. The only researched dose close to everyday life is 4% to 8% of body weight, from a small study in women with osteoporosis. For an 80 kg person, that is 3 to 6 kg. Start there, on flat ground, twice a week. Then increase time, weight and hills one at a time, with two weeks between each step.

Is rucking good for your bones?

It is weight-bearing, which the NHS highlights as important for bone health, and it is probably better than cycling or swimming alone. But no study has shown that rucking builds bone. The largest randomised trial of weighted vests we found, published in 2025 with 150 older adults, found that the vest did not offset the hip bone loss that came with weight loss. The loading with the best support for bone is impact, jumping and heavy strength training.

Does rucking count as strength training?

Usually not. The recommendation is muscle-strengthening work for all the major muscle groups on at least two days a week. The NHS also says the work should be hard enough that you need a short rest before you can carry on. A walk with a few kilos on your back rarely gets your legs there. Rucking is cardio with extra load. Put it alongside two strength sessions a week, not instead of them.

Is a weighted vest better than a backpack?

A load split between chest and back costs less energy than the same load on your back, and changes your gait less, according to the military research. In a study with nine participants, walkers used 5% less oxygen carrying a pack with front pockets than carrying a traditional rucksack. There is no study comparing a commercial weighted vest with a backpack in recreational walkers. An ordinary backpack with hip and chest straps, packed high and tight against your back, is plenty to get started.

Evidence base: Pandolf, Givoni and Goldman on the energy cost of load carriage in the Journal of Applied Physiology 1977 (PMID 908672), with our own calculations from the equation; the 2024 Adult Compendium of Physical Activities; Beavers and colleagues on weighted vests and resistance training during weight loss in older adults in JAMA Network Open 2025 (150 participants, PMID 40540267); Snow and colleagues on weighted vests and jumping in the Journal of Gerontology 2000 (PMID 10995045); Roghani and colleagues on walking with a weighted vest in osteoporosis in Rheumatology International 2013 (PMID 22441962); the meta-analysis of walking and bone density in Bone 2008 (PMID 18602880); Knapik, Reynolds and Harman on soldier load carriage in Military Medicine 2004 (PMID 14964502); Knapik and colleagues on rucksack palsy in the Journal of Special Operations Medicine 2016 (PMID 28088822); Lloyd and Cooke on load distribution in the European Journal of Applied Physiology 2000 (PMID 10774872); the UK consensus statement on exercise for osteoporosis in the British Journal of Sports Medicine 2022 (PMID 35577538); the WHO guidelines on physical activity 2020 (PMID 33239350); and NHS physical activity guidelines for adults and NHS guidance on preventing osteoporosis.