Is the forced part even necessary? It says the people were pushed harder than comfortable. You don't necessarily need someone cracking the whip to do that, especially with that kind of thing hanging over your head.
"You don't necessarily need someone cracking the whip to do that..."
You'd be surprised. Long-term goals are notoriously bad at motivating most people in the short run (hence, why procrastination is such a powerful force). So, even if you have the specter of something like total physiological degeneration looming over you, you're still going to work only to the brink of your comfort level unless someone pushes you further.
Anecdotal, but: I broke my arm a few years back in a really bad fall. Totally shattered a few of the bones in my right wrist (and I'm right-handed). Got a metal plate put in, and went through a year of physical thereapy. At the outset of the PT, I was told in no uncertain terms that I'd never regain proper movement of my right hand unless I worked my ass off every day at range-of-motion exercises -- which, at the time, were extraordinarily painful. So, in theory, sure, I could do them at home and never actually go in for PT. But whenever I did that, I'd work up to the edge of my comfort level, but never go past it. Conversely, when I went in for PT, having someone there to "crack the whip" pushed me past that discomfort threshold, and that's how I broke through the plateaus on the path to recovery.
The body's (and mind's) natural inclination is to avoid pain and discomfort, so you trick yourself into thinking you're working as hard as you can when you're actually not. And exercise isn't about working as hard as you can; it's about working harder than you can. That's where the progress happens.
I suppose the question is over the nature of forced.
I have a rowing machine which gives me a readout of speed/distance/cadence etc.
I 'force' myself to maintain a certain speed for a certain time even when it is quite uncomfortable. Is that sufficient for the 'forced' effect to come into play. I suspect it is.
Do you work out to the point of muscle failure? Do you maintain a speed so grueling that you literally can't row at all after a certain point? That's my interpretation of "forced," at least as experienced in my PT. Granted, I don't know what "forced" meant in the context of the study being talked about in this article. Accordngly, I can only guess at it. (No desire to play "No True Scotsman" on this, I assure you.)
In the article they said they tested them and if you went around 60 RPM on the bike the forced part was at 90 RPM. So they could measure swim pace then have them train at a higher pace.
From the article: "These findings are exciting, Dr. Alberts says, because they contrast with some earlier results involving voluntary exercise and Parkinson’s patients. In those experiments, the activity was helpful, but often in a limited, localized way. Weight training, for instance, led to stronger muscles, and slow walking increased walking speed and endurance. But such regimens typically did not improve Parkinson’s patients’ overall motor control... The forced pedaling regimen, on the other hand, did lead to better full-body movement control"
