Link: https://www.artofmanliness.com/health-fitness/fitness/heavyhands-walking-workout/

The idea for Heavyhands grew out of Schwartz’s discovery that the athletes with the highest VO2 max (generally considered the best indicator of cardiovascular fitness) were not cyclists, nor runners, but cross-country skiers.

Ok I saw that said in another place, but then my first suggestion is people should cross-country ski more if they can.

Part of the boost comes from training in the cold I think.

The other boost is making use of the whole body: arms and legs while exercising.

So this workout was trying to hold some weights in the arms while walking, to kind of be like skiing. I'd think you could also do what's called "nordic walking" which is basically like walking with ski poles on the ground. maybe add some weights to that?

Schwartz found that doing the “Heavyhands Walk” — essentially walking while pumping dumbbells with one’s arms — was the “best way to begin combined, four-limbed movements” and the most natural form of heavy-handed exercise.