Unilateral carries are great for the core. For those who don't know, unilateral training is a form of training which utilizes training one side of the body at a time. Unilateral training is a very functional form of training which transfers to many real world scenarios and to sports.
When one is training unilaterally the core has to work to balance the body and this helps with activating the core muscles.
Unilateral training helps with balancing imbalances in the body and thus preventing injury. The core needs to work harder during unilateral training to stabilize the spine and pelvis.
Unilateral caries are a great way to work the core and activate some of the deep core muscles. The core muscles are made up of transversus abdominis, multifidus, internal obligues, external obligues, rectus abdominis, pelvic floor muscles, sacrospinalis, logsisimus thoracis, trapezius, diaphragm, latissimus dorsi, gluteus maximus.
Some examples to unilateral carries are suitcase walks, kettlebell rack walks, kettlebell overhead walks, sandbag shoulder walks, waiter walks.
In video below you can see some of the common unilateral carries:
Below is a picture of one sided sand bag carries:
Below is a picture of kettlebell overhead unilateral carries:
A good advanced unilateral carry is the long log carries. When you carry a log on one side, your core has to work harder to balance the spine and the pelvis but when you do this exercise with a very long log, the log won't just mainly shift side to side but the two ends of the log will shift up and down at a greater extend while compared to short log carries. You will have to work harder to make sure the log does not fall backwards or forwards. This will get your abs involved at a whole new level. Once you master the short log carries I highly recommend getting a long log (it can be same weight) and doing the same exercise and trust me, it will feel much different. Try not to use your arms too much to to stabilize the log if you want to work on your core. I just use my arms to hold the log still and then use my core to stabilize it. This tip helps with getting your core in to the game A LOT more.
Check out Lucas Parker doing long log carries in image below. According to one of his videos, it seems like this is a one of his staple exercises.
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With short log carries you can do heavier loads so it has it's slightly different benefits. I recommend using a short log and long log for carries to get maximum benefits from your core training. Once you master the carries, the next step is learning how to do squats in this position.