Why don't I feel as exerted exercising on a rowing machine as I do with jogging, even when the rowing machine is on highest resistance?
Years ago I'm in between clients and a gym member comes up to ask a question.
"Is there any good substitute for running? I'm giving my achilles a break."
"Ehh, you can try the elliptical, but because of the lack of pounding, it's not really that similar."
"Yeah, the elliptical [expletive] sucks. So does the bike. Nothing is like actual running. Ok never mind. Later."
"[laughs] That's one way to put it. Have a good one."
This isn't unique to rowing. It's a common sentiment from anyone going from running to another activity. Most commonly when trying to cross train to give an overuse injury a break.
With rowing specifically -though this applies to biking, the elliptical and swimming too- an enormous difference compared to running is there is no loaded eccentric.
(There are other considerations here, but I'm only going to hit this one.)
- Concentric = muscles shortening
- Eccentric = muscles lengthening
Let's think about the muscles on the front of our thighs, the quadriceps. When we run, we concentrically use the quads when we straighten the knee (think pushing off). We eccentrically use the quads when we bend the knee (think landing before pushing off).
With rowing, we concentrically use the quads as we push back and straighten the legs against the machine's resistance. We eccentrically...don't do much! There isn't any resistance on the way back in, as our knees bend, and the arms can largely get the body pulled back in with zero quadricep involvement.
It might not sound like much, but in one sense you could consider a mile of rowing as half the work as a mile of running, as in rowing the body is only working in one direction.
The lack of eccentric loading is the reason Lance Armstrong could dominate the Tour de France, yet say about the New York City Marathon,
"I can tell you, 20 years of pro sports, endurance sports, from triathlons to cycling, all of the Tours - even the worst days on the Tours - nothing was as hard as that, and nothing left me feeling the way I feel now, in terms of just sheer fatigue and soreness"
The body is incredibly specific in its adaptations. It's not easily fooled. You could even try to replicate your running training on an elliptical, which, to the eyes, looks like the exact same movement. You could do this where you end up maintaining your VO2 max, a beloved metric of the endurance world.
Nope. Still won't work. Your running performance still goes down.
Doesn't mean rowing, swimming, biking, etc. aren't beneficial in a general health sense. But they don't feel like running because they aren't.