I agree with Apollo. Use the vest when the Camino is 3 or more months away, with some backpack workouts when convenient, but transition to using mostly your backpack in the 2 months before your Camino. This approach will have the most benefits, and is similiar to what serious athletes do: cross-train for generalized strength during the off season and then get "sport-specific" as the season approaches. You'll get a base of overall strength with benefits for a wider range of activities, reducing your risk of injury. Two months is plenty of time to develop "Camino-specific" strength for the actual walking. You can more safely do a much wider range of exercises with a vest. Insert some side lunges, get ups, planks, etc for variety in your vest walks. Just ramp the weight up gradually to stay uninjured. Practice climbing up into the upper bunk of a bunk bed with it on - haha! This will make you more resilient, flexible and injury resistant overall.
Thank you
@GaryRobArms for saying exactly what I would say.
There is a persistent belief here that the best way to train for the Camino is to simulate the hiking as much as possible. It is understandable because it is intuitively logical, but it is not at all what we know about and practice for modern sports conditioning.
The benefit of cross training is a fundamental. Who do you think will do better in a swimming competition, a swimmer who trains twenty hours a week by swimming or one who also trains for twenty hours a week, but cross trains by swimming for 16 hours and running or cycling for the other four? The answer is counterintuitive, but very well established, and it is the one who cross trains. So applying that to Camino preparation, that means that it is
not best to prepare by only hiking, wearing your pack and boots. It would be much more beneficial to spend some time - and give your joints a break - by also doing some swimming, cycling, rowing or some other completely different work out.
Another misconception I often see is the idea that we only need to strengthen the muscles that are most used when hiking. Again, that may seem most logical, but it is not true. Whole body strength conditioning is necessary to prepare for any physical activity, the more the better. This is especially important for preventing injuries because, for example if one trips, one unexpectedly needs to use ‘non-hiking’ muscles to stop oneself from falling. If those other muscles are too weak because the poor misguided pilgrim thought ‘to prepare to hike, I need only to hike,’ then those other muscles won’t be strong enough to keep him upright.
I think a weighted vest is an excellent idea, and I have used one myself. Start with much lower weight than 12 pounds. Mine is 8 pounds, and that’s plenty, and I worked up to that amount. The idea that it uses slightly different muscles than wearing a pack is a
good thing, not a bad one as it provides a bit of more general conditioning. A vest does not hang on your shoulders, as some have suggested. It fits pretty tightly around your chest and the weight is borne pretty directly downward through your hips. Because it is distributed evenly front and back, it’s quite comfortable. I think it only moderately works your back and abdominal muscles, but is a great workout for your legs and glutes. Another advantage is that you can walk around town wearing it inconspicuously, unlike a pack. For me, it helped a lot as an intermediary step to carrying a full pack.
It’s amazing how light your gear feels on the trail after training heavy and with resistance leading up to the trip! Thanks for sharing that!
