So after playing around and shooting that video I went for a proper 5k run with the vest and my big takeaway is that I agree with myself, it needs some padding in the shoulders. My shoulders are scratched and bruised.
The jostle is minimal though which is very good.
The interesting thing about running with a weight vest is it really improves your (or maybe just my) foot fall. You want your foot landing under your center of gravity and you want to be landing on your whole foot, not toe or heel, it’s the most stable position possible. Well with forty extra pounds above my legs my body searched for and found the most stable position possible.
Plus the vest keeps your upper body upright so I’d say it’s a cure-all for run form. Or at least a cure-most. It’s hard to have a good long stride when your body feels like it’s going to crash through the earth during non-contact.
And I was exhausted when I finished the lap, nice extra strain in the legs and the lungs. In my totally subjective estimation I’d say it felt like I did 20k rather than 5.
Sometimes the best part of a weight vest is taking it off, I went for another lap without it and it felt amazing. I remember at the Stampede Road Race a dude was warming up with a vest and it makes perfect sense now, it tightens up your form and then, when you take it off, you feel springy and relaxed.