Everything in creation seems to be personalized now. I’m not just talking about monogrammed water bottles or customized sneakers. It seems we are all in search of our own secret sauce for fitness training, medical care, personal growth, career development, perhaps even creative endeavors. You name it, there’s a specialized 23-and-me-style approach to it. Forget one-size-fits-all. That’s out. Make way for precision medicine and personalized training, designed just for you.
Except that a new study came out saying that, at least for fitness training, personalized workout plans aren’t necessary. This article in Outside magazine offers a detailed summary, with graphs and everything.
So what’s the upshot here? I’ll break this down.
Once upon a time, there were standard training and exercise plans, designed to improve various areas of fitness– strength, endurance, agility, speed, etc. Some folks responded better than others on these plans. How to help those whose performance didn’t improve as much? Answer: personalized training. It seems intuitive. But is there evidence for this?
Researchers thought so until recently. So what happened to change their minds? Answer: a lot of studies, one of which is this cool and very carefully analyzed studies of variations on changes in VO2 max (a measure of aerobic fitness) over the course of a study for both exercise and control groups. Here’s a graph of what they found in a 2019 study:
Here’s what the Outside article said about it:
We see exactly the same variation in response in the control and exercise groups. The only difference is that the exercise group is shifted upward by the average response of about 0.2 liters per minute. So the variation in response can’t be because some people “respond” to exercise (or to the specific workouts prescribed) while others don’t—because the subjects in the control group had a similar range of response and non-response to doing absolutely nothing.
Wow. That is very surprising and counterintuitive.
Fast forward to August 2024, when a new meta-analysis came out “to evaluate inter-individual differences in VO2max trainability across aerobic exercise training protocols utilizing non-exercising comparator groups.” They found that the variation for changes in VO2 max in the exercise groups were less than the variation in the control groups. That means that there’s just not evidence of variation in individual response in the exercise groups.
But but… it’s just a fact that some people are stronger responders than others to exercise and workout plans. Yes, this is true. What this (and a bunch of other) studies are saying is that the variation we see and experience may not be due to our individual training response (whatever that may be). There are lots of reasons for variability in response, both within an individual over time and between individuals in the same program. The Outside article explains:
If there is true variability in training response, though, it seems to be trivial compared to other sources of variability. One of the main ones is measurement error: if you’re measured slightly below your true value on the baseline test and slightly above on the final test, you’ll look like a strong responder—and vice versa. There’s also “within-subject variability”: changes in behavior or environment that have nothing to do with the exercise program being tested, like sleep, diet, or stress. These external factors might even be influenced by your genes…
So what does this mean for us, the pursuers of fitness and sport and improved performance? Science is not telling us to fire all personal trainers or stop focusing on specific areas in which we want to improve our responses. What these studies are saying is that training itself is good for all of us. There are decades-old, time-tested, reliable plans out there that have been shown to work for groups in large studies. We don’t need super-personalized, dialed-in, specialized workout plans just for us. We’re all individuals, but training is training, as the Outside article says at the end.
For me, this comes as a relief. Life is complicated, and if I can just make use of the standard workouts without having to go to a lab and get wired up for an extensive and expensive evaluation and detailed fitness plan, I am very happy to hear it.
Readers, what do you think about these new results? Are you relieved, annoyed, shocked? I’d love to hear from you.
