Back in January, I wrote a column on the sports/fitness science topics I expected to see in the headlines in 2013. Time to check back and see how I did.

1. The obesity paradox: "...lately, critics have argued that carrying a few 'extra' pounds carries no health penalty, and in fact might help you live longer."

Well, this is good timing. Just today, about a new meta-analysis in the Annals of Internal Medicine that disputes the very existence of "healthy overweight." What they found is that if you look only at studies with at least 10 years' follow-up, even those who were otherwise "metabolically healthy" were more likely to die or suffer cardiovascular events during the study if they were overweight. In other words, the idea that you can be "fat but fit" is a myth.

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Is this the end of the debate? Not likely. After all, there's some very good evidence that aerobic fitness is better than weight for predicting future health. But saying fitness is more important than fatness isn't the same as saying fatness doesn't matter at all, or that it's actually good. The new study offers some much-needed pushback against that idea. Hopefully, as time passes, we'll end up somewhere in the middle: not stigmatizing or catastrophizing fat, but not celebrating it either.

2. Barefoot running: "The burning question is whether these changes reduce your risk of injury. There are reasons to think this should be true, but proper randomized studies take time – which is why we’ll finally start accumulating meaningful data this year."

In truth, I don't think this particular debate has advanced much this year. There have been some interesting studies, like this finding that a static measure of foot pronation made no difference to injury rates even when all the runners were given identical shoes. But anyone waiting for a definitive "Aha!" moment where we finally find out that minimalist shoes are or aren't better than cushioned shoes is still waiting.

Instead, I think what's happened this year is the gradual, continuing "normalization" of the idea that lighter and more minimal shoes might be a good option for at least some people. I hear less from the extremes of the debate (i.e. that barefoot is the only "right" way to run, or that minimalism is totally crazy), and more focus on figuring out what works for individuals. And that's a good thing.

3. Pollution and exercise: "Inhaling particulates emitted by cars and trucks spurs inflammation that spreads throughout the body. Exercise, on the other hand, helps your body fight inflammation. But which effect wins?"

We have indeed seen further research on this topic, including the curious finding that breathing polluted air seems to have greater effects during moderate exercise than during vigorous exercise. In a sense, findings like this raise more questions than they answer, so we'll continue to watch for more on this topic.

4. Supplements vs. foods: "Researchers are beginning to focus on the broader context of dietary patterns, stepping back to understand healthy eating as a whole that’s greater than the sum of its micronutrient parts."

I think this prediction was on the money -- though that may have been a self-fulfilling prophecy, since I'm quite interested in this idea and thus have been watching for related research. One example of this topic getting attention was a pair of studies suggesting that high doses of resveratrol (an antioxidant found in red wine) may interfere with some of the benefits of exercise, which I wrote about here. I also wrote a piece for Outside magazine a few months ago on the potential downsides of supplements for athletes.

5. Overdosing on recovery: "Post-workout aids like ice baths and anti-inflammatories can help limit muscle damage and accelerate repair after intense workouts. But in doing so, they may suppress the signals that tell an athlete’s body to adapt and get stronger."

This is an idea that continues to be discussed among sports scientists and coaches, but it's not clear whether it's a significant concern in real-world conditions. Does too much time in the ice-bath really hinder your fitness gains? We're still waiting for studies to provide a clearer answer. In the meantime, my personal feeling is that athletes should aim to use the "minimum effective dose" of recovery that allows them to achieve their training goals in the next session. Don't abstain from recovery aids if it will compromise your next day's training; but don't do more than you need to.

6. Epigenetics: "A single hard workout can switch on previously dormant areas of DNA that affect how you metabolize energy. Other studies suggest that epigenetic changes allow environmentally driven traits such as obesity to be passed from parent to child."

Let's call this one a miss. It's an area of active research and great potential, but I can't say there were any particular advances over the past year that leap to mind.

Okay, time to start thinking about 2014. Anyone have suggestions?

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