Fascinating clip ! Thank you for sharing ! Sounds like the late great Mr Fairbanks is talking about later would be called isometric exercises, which can be done anywhere, at any time, with no equipment. The body uses itself for resistance. He looks wonderfully fit here. Surprised he be felled by a fatal heart attack only about 10 yrs later (in 1939). One of Hollywood's true icons.
Having read a biography about the first King of Hollywood (his second wife Mary Pickford was the Queen) Douglas was always an exercise type of guy. Always fit as his ability to do stunts and leaps without a double will attest. I learned he had a trench below sidewalk grade built at his studio deep enough to jog in without clothes on. He believed the skin must breathe and practiced naked exercise (discretely of course). The trouble was though he did not drink much, he was a smoker. Later on in his fifties the actor suffered a sudden coronary event and died after his career had basically slowed to a crawl with the coming of sound pictures. He reconciled (mostly) with his actor son Fairbanks Jr. before his death, and his son was kind in his praise in the interviews I have seen.
The documentary this is from is AROUND THE WORLD IN 80 MINUTES and is available at Amazon www.amazon.com/Around-World-Minutes-Douglas-Fairbanks/dp/B003F1Y29Q