After decades of dominance by aerobics and "cardio," strength has made a comeback. Even some doctors have begun to catch up with the literature on the value of resistance training for health. Unfortunately, even when doctors do prescribe strength training, they usually screw it up: Wrong formulation. Wrong dose. Wrong frequency. Wrong route of administration. Wrong therapeutic targets.
The completely counterproductive prescription usually looks like this: Wrong Rx: Light Weights for High Repetitions.
And that's just completely back-asswards, on multiple levels. It betokens a complete ignorance of the role of volume and intensity in the training program. It shows that the prescriber does not know that older adults are volume-sensitive and intensity-dependent.
By volume-sensitive, I mean that very high-repetition work, even with light weights, can be hard on aging joints and tendons, producing soreness, stiffness, joint pain, and systemic inflammation. And if this high-volume work is done at low weight, soreness and inflammation is all it will produce, without increasing strength.
Intensity-dependence means that strength can only be built and maintained by lifting heavy weight. All athletes, of all ages, are intensity-dependent, but older adults are even more so. A kid can put up a new personal record in the deadlift, take a layoff or a deload, and approach, hit, or surpass the same weight a month later. (Punk. I hate him.) This is not the case for older athletes. Without frequent exposure to high-intensity weight, we will detrain far more rapidly than our younger, less deserving counterparts.
The doctors, coaches, and fitness gurus who persist in writing the "low-weight-high-rep" prescription got a big boost from a highly publicized research article by Morton et al, which claimed to show that people got just as strong on a low-wt-high-rep program as on a high-weight-low-rep program. The response from the Interwebz and the media was entirely predictable. "Get just as strong from lifting low weights!" Easy, you see, can work just as well as hard. You can get the same results from a little effort as you can with a lot of effort.
If that sounds too good to be true...well, it is. At the 2016 National Conference of the Starting Strength Coaches Association, I put together a panel of health care and fitness professionals to evaluate and discuss the Morton paper.
These panelists are some of the smartest guys I know. Austin Baraki MD is a physician, coach, and powerlifter. CJ Gotcher is a strength and conditioning coach and competitive lifter with a keen eye for the research literature and methodology. Dr. John Petrizzo is a Doctor of Physical Therapy, Starting Strength Coach, and faculty in the department of Exercise Physiology at Adelphi University.
When I put these guys on the Morton paper, they went to town.
We found a lot to like about the Morton paper, including the statistical analysis and data presentation. And we said so. But we also found major gaps between the claims and the data, and huge problems with the experimental model. The most important of these was that, although the authors claimed to show that a low-wt-high-rep program worked as well as a high-wt-low-rep program, they didn't actually include a high-wt-low-rep program in their experimental model or analysis. This boggles the mind. It's as if you did a study of apples and oranges, found that oranges tasted better, and concluded from this that oranges are better strawberries.
The paper has many critical flaws, but the one noted above is so major, so devastating, and so laughable as to make the entire study worthless. One wonders how it ever got past peer review. We don't have to wonder how it got past the media's filters...because they don't have any.
So when your doctor tells you that there's "new science" saying you can get just as strong with light weights as heavy weights, you'll know two things: (1) He's probably talking about the paper by Morton et al; and (2) he either didn't read it, or didn't know how to read it--neither of which speaks well of him. The panel discussion linked above is the abridged version. The nerds among you will find a link to the longer version below.