Loaded carries are much touted as a fantastic way to train the core musculature while simultaneously improving grip strength and work capacity.
But are they the best way to perform carries?
Firstly, we need to distinguish between physical capacity and core competency. What most people chase when they use farmer walks is to grab the heaviest thing they can hold onto and then walk as far as they can. That is not necessarily the same thing as training for core control – don’t ever confuse quality and quantity.
To begin we need to define some terms.
Functional training – to improve ability in an upright bipedal stance. If gait or posture is negatively affected, then the training has actually reduced function as one or both have been negatively impacted.
Core control - The core’s real function is to protect the spine, especially from flexion and rotation at the same time. Sahrmann wrote, “The keys to preventing and alleviating spinal dysfunction are (1) to have the trunk muscles hold the vertebral column and pelvis in their optimal alignments and (2) to prevent unnecessary movement.” (Diagnosis and Treatment of Movement Impairment Syndromes).
The functions of the core are usually only thought of in terms of activities. That is, they can perform lateral flexion, rotation, and flexion. However, they can also oppose all those movements and when viewed through the lens of improving function genuine core control isn’t as simple as moving the most weight possible.
Good core control allows you to maintain pelvic and muscular function and alignment. If you use the heaviest weight you can for farmer walks you will not walk with normal gait. So it’s both non-functional as well as reducing core control. It may be useful for core capacity, but that is different to core control.
Returning to functional training for a moment, and with a quick glance at human evolution, we see a clear pattern. We were designed to do things contralaterally. That is, when one lower limb moves, the opposite side upper limb moves too. You can see it in both walking and running but it is also how we kick, throw, and punch. Everything powerful that we do athletically is done contralaterally.
McGill showed that a unilateral carry creates greater muscle activation, particularly in the opposite side’s external oblique and glute medius. However, the missing part for most people is that he didn’t focus on limit loads, but on loads of roughly a third of bodyweight. In his test he used a 30kg load.
That may not seem like it would be heavy enough to work but consider the reality of trying to unilaterally hold a load while trying to walk with perfect gait and posture. As it gets heavier the first thing that happens is that the weight bumps into your leg changing your gait. The second thing that happens is that posture will change to counterbalance the load. Neither are enforcing good posture or gait.
I happened to be part of FMS when Grey Cook first introduced their now well-known six position carry test. This is a unilateral carry test where you simply walk while holding a kettlebell in one of six positions. The positions are right and left suitcase walk, right and left rack walk, and right and left overhead walk. For the test I used a 20kg kettlebell while weighing 85kg. In the suitcase position we see optimal activation at loads of 35%- 45% of bodyweight.
Step one in the process of developing a healthy lower back and optimal core control will be to use a load that is somewhere between 20%-30% of bodyweight as a starting point.
But what if we want to go further? What if we’ve developed competency and now want to develop capacity? How do we do that while still addressing core competency?
FMS have now introduced a functional capacity test that is a farmer walk using 50%-75% of bodyweight with an expectation that you can cover at least 250 yards in 90 seconds. While that might be a great test, 75% of bodyweight isn’t going to be much use to an emergency services worker wearing 20kg of gear and having to drag a possibly unconscious victim to safety. How do you achieve the strength to do that while using less weight and maintaining good gait patterns?
Because we know based off both evolution and research that muscle activation in various core musculature is increased when the load is contralaterally held, we can expand this out to much heavier loads but still maintain the feel of it being unilateral. Research shows that as load increases, muscle activation does too. For example, a 100kg farmer walk could be performed as 40kg in one hand while the other holds 60kg. The best way to accomplish this and not negatively impact gait is with a trap bar or specific farmer walk handles that allow loads to be carried that don’t get in the way of your legs.
If we consider all of the muscles of the core based off Sahrmann’s quote above, we need to look beyond just muscles of the midsection though. For instance, because the lat borders the spine for roughly two thirds of the spine’s length, it has a role in spinal stability. Similarly, the muscles that control shoulder function such as the rhomboids and traps will also play a role in core control.
Not surprisingly, as weight is moved up the body from the suitcase position to the rack position and then overhead we see muscle activation increase in the upper body muscles. Choosing between 15%, 20%, and 25% of bodyweight in the overhead position we see muscle activation increase in both lower and upper traps, serratus anterior, and latissimus dorsi as load increases, with corresponding increases in trunk muscles, especially both obliques. However, greatest activation of those same upper body muscles is seen in the rack position. For the rack position we would pick loads of 25% - 35% of bodyweight.
Why would you choose one position over the other?
For greatest loads lifted you would always pick a symmetrical load and hand position such as the farmer walk. It is our naturally preferred way to carry anything for a reason. If you want to use maximal load but in an asymmetrical loading you would pick the farmer walk still but adjust the loads so one side is significantly more than the other. For best results I would use 60/ 40 as the balance as you will find 70/ 30 very difficult as loads increase and grip, not core stability, will become the limiting factor.
However, if we want to maximise core muscle activation we would choose both an asymmetrical load as well as an asymmetrical carry. For best results allowing maximum loads you would pick the suitcase carry on one side and rack carry on the other. The hardest part of this movement is getting the racked bell into place and then keeping it there while you suitcase deadlift the other bell into place. For this reason, the racked bell should be kept limited to 25% of bodyweight. The lower bell can be made as heavy as you want. A good rule of thumb is to aim for a maximum of 75% bodyweight total meaning an 85kg athlete would use a 24kg kettlebell in the rack position, while using a 40kg bell for the suitcase carry.
Overhead carries can be added in but the loads used should be lowered to a maximum of 25% of bodyweight. The most convenient ways to do this is to get your overhead weight into the rack position, suitcase deadlift the other weight in the opposite hand, and then press your racked weight to overhead.
While studies show that an overhead asymmetrical, unstable load increase activation I will caution people against a double hands overhead walk. It seems like a good idea looking at it on paper and they can certainly be very challenging. However, the realities of modern work, poor posture, and stiff shoulders usually mean that people will do something odd with their heads to counter their lack of shoulder mobility. That could lead to something as benign as a sore neck or it could lead to something as severe as a broken bone in their neck. (Sadly not an exaggeration. I have seen someone snap a spinous process in their neck from getting a kettlebell overhead and having to fixate it there. An injury known as a clay shoveler fracture). When I started to see a lot of clients getting sore necks when I introduced double overhead carries I removed them from my programming and all neck issues cleared up.
Core control is very different for a someone who only trains in the gym versus someone who actively pursues outdoor activities or works in any kind of tactical or emergency service. A strongman competes in events that usually last two minutes or less. A mountain athlete or tactical operator may need to stabilise their spine under the heavy load of a pack, while carrying a weapon or fire fighting equipment, for many hours. For that reason I like longer sets of 60-90 seconds. Because the loads are relatively light this should offer no massive grip issues for people. These longer than normal sets will teach both core control as well as strength endurance of the core muscles.
Because set length is relatively long this should be treated like any other strength endurance work and performed two to three times per week for three to four sets at a time. This would tie in excellently with heavy sandbag get ups for maximal strength and then the asymmetrical carries for longer periods. This is a great representation of what it is like getting your heavy pack on once loaded with game, getting to your feet, and then beginning the haul out. Or, getting your teammate into a fireman’s carry and then getting him or her to safety.