I believe Armstrong had an abnormally slow pulse rate and used to shadow box up to 15 rounds before he fought
Henry Armstrong supposedly had a resting pulse in the low 40s...He was called perpetual motion for a good reason pumping his two fists and literally using his head as a battering ram, always on the attack, never taking a backstep...In my eyes the best featherweight ever...I saw Armstrong twice ringside , once against the rising sensation Beau Jack in 1943, when Henry past his peak was outsped by young Beau Jack and months later when Ray Robinson "toyed" with his idol and never tried to hurt his idol Armstrong, winning a 10 round decision...All of us in the crowd sensed this...
Wow. What a pleasure to have seen that. Funny how those old greats even when they deteriorate don't get ko'd. I had heard about that Armstrong pulse rate thing--someone told me once that was like Wayne Gretzky. They could recouperate and get a second wind much much faster than anyone else. Their gastank never went below like half a tank. Seemingly never tired and Gretzky was hardly an imposing physical speciman. But most people would still factor in a big right hand as being far more important, wouldn't they?
I think the difference between most "high workrate" fighters such as Jackie Kid Berg and others compared to Henry Armstrong, was that Ole Henry put so much more power into his constant barrages than his imitators who had to expend less energy during the bout...Henry was one of a kind whose nemesis was Sir Fritzie Zivic...
Seems like a lot of fighters don't appreciate how important a high work rate is. There have been some boxers who were quite ordinary, like Troy Dorsey, for example, who were able to put together a nice run (like Dorsey did against fighters like Jorge Paez, Tom Johnson, and Bernardo Pinango) simply on the fact that they never stopped punching. Dorsey wasn't around long. But when he went on his run, it was all due to the fact that he just kept throwing from the beginning to the end of a round. https://www.youtube.com/watch?v=LHAwTuKpifM
Everyone gets knocked out if they fight often enough, even the old greats. The list of guys who didn't get knocked out is pretty short. There's Jake LaMotta and then a handful of other guys. Armstrong was knocked out twice. His first fight, and once by Fritzie Zivic. Even Ray Robinson had to quit on his stool against Joey Maxim. Ray Robinson vs Henry Armstrong. Robinson must have been able to hit him from across the ring. I'm trying to figure out if the size mismatch would have been worse than Tommy Hearns vs Roberto Duran. Robinson is 5'11" 72.5" reach, Armstrong is 5'5.5" and 67". 5.5" height advantage 5.5" reach advantage. Tommy Hearns was 6'1" 78", Roberto Duran was 5'7" 66". Height advantage 6" reach advantage 12".
On the basis of sheer bout numbers without ever being stopped, Jack Britton went about 330 bouts or so without being kod, and Harry Greb went about 270 fights til he retired, without suffering a stoppage. Truly amazing stats for both men...