The “fullpack” as we call it in the Philippines, refers to the big backpacks mountaineers carry on multi-day packs. In the past when gears like stoves have not yet undergone miniaturisation, the packs were even heavier, but even today hikers must have the ability to carry a heavy backpack – for multi-day hikes and also for emergency situations. Improper use of, and inadequate training for carrying a heavy backpack can lead to injuries and back pain.
First, let me state the basic principle that most of the weight of the backpack should be borne by the hips, at the level of the waist. This is what the hip belt or waist strap is for, and this is why we pack our bags in such a way that the weight is closer to the body and located higher in the pack.
1. When you lift your backpack to place onto your back, you use your shoulder muscles (i.e. deltoids). Throughout the hike you will do this a number of times so make sure that you also have enough strength.
How to exercise them: Dumbbell and barbell raises, shoulder presses
2. The trapezius muscles (“traps”) are your upper back muscles that radiate all the way to the neck: they are crucial for carrying your pack, not just for their muscle power, but because the muscles themselves are where the shoulder harness sits and they’re not strong or robust enough it could lead to soreness and pain. One Israeli study in 2013 found that carrying a backpack can damage the nerves at the upper back and this may be mitigated by stronger muscles.
How to exercise them: Pull ups, dumbbell or barbell shrugs, rows, etc. Shoulder shrugs are useful particularly for the upper trapezoids on which the backpack strap sits.
Interestingly, the abdominal muscles (“abs”) are also very important in supporting your backpack, especially in mountains that require a lot of bending, twisting, and turning (i.e. Talomo-Apo Traverse), and at the same time maintaining your posture.
How to exercise them: Planks, hanging leg raises, crunches
The middle and lower back muscles are also involved in carrying a backpack. Like the abdominal muscles, they stabilise the body and prevent fatigue especially on longer hikes.
How to exercise them: Planks, squats, core exercises
Of course, the quadriceps (“quads”) and all the leg muscles are also essential not just for hiking itself but for carrying a backpack, which adds to the weight that the body needs to lift itself especially when doing steep hikes. If they are weak, the weight will borne by the knees and can cause knee injuries including the patellofemoral syndrome (PFS).
How to exercise them: Squats, deadlifts, leg presses
1. Because of all the repetitions that you’re doing through the hike, you can actually think of hiking is a one long leg workout, and to some extent it also works out your abs – though this can not be said of the back muscles.
2. But careful not to overdo it too much: if the backpack is too heavy it can also affect your body and cause back pain. Gradually increasing weights of backpack can help and you can also do it before the hike: by doing walks with a backpack with you, progressively adding weight until you reach the expected weight of your hiking pack.
3. Make sure that you are wearing your backpack properly, with the hip belt adjusted to make sure the weight distribution is more towards the pelvis and the upper back (see diagram on the side.