In science, it's good to have an open mind, because we're always discovering new things that change the "facts" we were once so certain of.
But too many scientists get stuck in a groove, and they can't be budged from the current dogma, even when the evidence doesn't support their beliefs.
This is apparent in the eternal debate about the best diet. One problem is that people are different, they interpret diets differently, they keep track of what they're actually eating differently, they have different exercise patterns, they take different drugs, and so on and so on. But focus on "evidence-based medicine" means physicians won't believe anything unless it's been proved in a double-blinded controlled randomized trial.
And because such trials involve large groups of people, some of them usually respond one way and others respond in another way, and only statistical analysis will show whether the intervention worked on average. It says nothing about how the intervention will work on any individual patient in the future.
Nevertheless, what bothers me is the tendency of the scientists doing these trials to interpret the results in the light of their own biases. One such ploy when your intervention didn't work is to suggest that you didn't intervene hard enough.
For example, when a study of l0w-fat diets resulted in no benefit, the researchers said maybe the fat content wasn't low enough, that the study should be repeated with even less fat in the diet. It didn't seem to occur to them that perhaps lowering the fat content of the diet wasn't helpful.
A recent study shows the same type of reasoning. This study showed that adding moderate exercise (walking) to diet in people with type 2 diabetes resulted in no benefit for hemoglobin A1c. The first explanation by the lead author of the study was that "the activity chosen, walking, was suboptimal."
In other words, if the exercise you used shows no benefit, maybe more exercise will help.
A lot of studies have shown that exercise doesn't contribute to weight loss. Just Google "exercise, weight loss, doesn't help" for a smorgasbord of articles. Often, exercise just makes you hungrier. Other studies have shown that diet and exercise do work better for overall fitness than either diet or exercise alone.
Exercise helps the cardiovascular system and is certainly a good thing to get. (So why am I sitting here typing instead of finishing the wood stacking I started this morning? Answer: I'm human, just like you.)
I'm not suggesting that exercise is bad. What bothers me is the knee-jerk reaction of some science investigators. "My study doesn't support my hypothesis, so maybe the study wasn't done right" instead of "My study doesn't support my hypothesis, so maybe the hypothesis is wrong."
If everyone thought like this, we'd never make any progress.
Luckily, there are always a few brave souls who dare to defy the current dogma. They're usually laughed at when they start, and some of them give up. Some persist. And they're the ones who end up with the Nobel Prizes.