Roundups

This article was originally posted by Ryan at the original HillRunner.com Blogs.

I’m leaning heavily on one of my favorite blogs this week. Alex Hutchinson’s Sweat Science blog is always a good one. This week, two of my favorite reads came from there.

Protein before bed

We’ve known for some time that it’s best to spread your protein intake out across the day. Your body can only process around 20-25 grams at one time. If you take more, it doesn’t really do anything for you.

So, would getting an extra dose of protein right before bed be beneficial or do things change as we go to sleep?

We now have the answer.

More generally, think in terms of getting four to six distinct doses of protein throughout the day and evening.

To me, that’s the key. Is the timing of that before bed dose of protein significant? Probably not. The key is that it was an extra dose of protein spaced out from the others throughout the day. Whether it comes at bedtime, when you first wake up or some other time during the day probably doesn’t matter. What matters is that it does come.

Compression socks

Do you believe compression socks will help you recover? If so, good news. If not, bad news.

That’s what a recent study tells us.

So for the believers, there was a tiny (and non-significant) speed-up in the second trial, while the skeptics had a significant (and unsurprising) slow-down. The error bars here are +/- ~20 seconds, but the difference is still striking.

This was a test of two 5K time trials with an hour between the two. The question was whether wearing the compression socks between the trials would affect the second. As it turns out, those who believed the compression socks would help them ran about 3 seconds faster on the second time trial. Those who didn’t believe ran about 17-18 seconds slower on the second time trial.

While this result is within the margin of error so we can’t say this result is conclusive, that’s a pretty amazing spread.

That’s the likely power of the placebo. Our minds are amazing things.

This article was originally posted by Ryan at the original HillRunner.com Blogs.

A long lasting debate and an important reminder this week.

Antioxidants

First, the reminder.

Back when I was a relatively new runner, everyone believed antioxidants were very good for runners. The belief was the more, the better. Antioxidants would help you recover from your training faster, which would allow you to train harder.

Conceptually, this makes great sense. In fact, upon a recommendation from a doctor who was also a good runner, I took mega doses of antioxidants for many years. I have to wonder now, though, in the face of more recent evidence how much those mega doses of antioxidants may have harmed my fitness.

Well, here’s more to get me thinking:

On the basis of vitamin E and NAC studies, acute intake of antioxidants is likely to be beneficial. However, chronic intakes of most antioxidants have a harmful effect on performance.

So short term supplementation may make sense. Long term? Forget it. It’s likely to do more harm than good.

Fitness vs. efficiency

There’s been a long debate over whether increased fitness decreases one’s efficiency. On one hand, it wouldn’t seem that one would directly affect the other. On the other hand, it seems that the people with the best fitness as measured by VO2max are not those with the best running economy. Even the elites tend to be great in one or the other but not both.

There is some new research that took a look at two questions:

1) If you have a high VO2max, are you more likely to have a lower running economy?

…there is an inverse relationship between VO2 max and running economy: those who are good in one are less likely to be good in the other. But it’s a pretty scattered relationship. Overall, knowing someone’s VO2 max accounts for only seven percent of the variance in their running economy. The rest is determined by other factors.

So the answer is yes but not by a significant margin.

2) If you improve your VO2max, does that mean you’re more likely to make your economy worse?

Again, those who improved VO2 max were slightly less likely to improve running economy. In this case, knowing the change in VO2 max explained 12 percent of the variance in running economy changes.

Again, yes but not by much.

So it’s true that a better VO2max apparently is associated with worse running economy but the relationship is weak. It’s not a death knell. You can improve both at the same time and you can do well in both measures.

This article was originally posted by Ryan at the original HillRunner.com Blogs.

This week, I have an interesting roundup post on the benefits of massage and adapting to burn fat as fuel.

Benefits of massage

We all know massage feels good, right? But does it do anything physiologically to actually make us better runners?

It appears so.

We’ve already known that inflammation is reduced and mitochondria (the "power plants" of the muscles) growth is increased when muscle is massaged after exercise.

Now, there is evidence of more benefits. More blood vessels, less scar tissue and more muscle fiber regeneration.

Also noted is that massage immediately after exercise is better than 24 or 48 hours later. Timing matters.

Adapting to burn fat as fuel

A few months ago, I wrote about the idea of the low carb/high fat diet in relation to runners. I noted in there that we simply can’t burn fat quickly enough, even after adapting to burn fat as fuel, to support 5K or even marathon pace. I received a couple emails from LCHF advocates in which they called me a liar and one said a few other things. Such is life on the Internet, right?

Well, I directed them to some evidence that you indeed can’t burn fat quickly enough to support even marathon pace. Now, I have more evidence I can direct them to.

As noted in the image there, you’re pretty much out of luck on burning enough fat to power yourself through a 5K or 10K if you’re focused on racing. As for the marathon, if you’re a 176 pound marathoner you could train yourself to burn enough fat to get you to the finish line in 4.5 hours. If you’re a 132 pound runner, you can train yourself to burn enough fat to get you to the finish line in 3.1 hours. Any faster and you’re going to need glycogen (carbs).

This article was originally posted by Ryan at the original HillRunner.com Blogs.

A couple good topics for this week’s round-up. Who could pass up the headline "Slushies vs. Frozen Underwear for Hot-Weather Workout"? Not only a killer headline but an interesting topic. Also, how important is eating breakfast for your running if you run in the evening?

Slushies vs. frozen underwear?

Would you rather wear frozen underwear or eat a slushie? Easy call, right?

Well, maybe not if you’re interested in performance in hot weather. Or at least not the answer you were just thinking.

Maybe we should go for that frozen underwear after all.

But the results also indicate that if you use only one type of precooling, you might want to concentrate on icing your skin instead of your stomach, since the effects seem to linger longer.

It’s important to note that both methods of cooling had benefits but it appears cooling the skin is more long lasting than cooling the gut.

The practical take home of this is do what you can to keep cool before a warm weather run. Cooling the skin is better than cooling the gut but both are good.

Eat your breakfast!

We always hear about the importance of breakfast. How important is it for runners?

Apparently, very important:

They measured exercise performance (30 minutes of steady-state cycling followed by a 30-minute time-trial) at 5 p.m., with or without breakfast. The subjects had eaten as much as they wanted for lunch (and the subjects did indeed eat about 200 calories more after skipping breakfast compared to when they ate breakfast), but this wasn’t enough to make up the deficit. Time-trial performance was 4.5 percent worse after skipping breakfast.

As noted in that article, it is important to note that these were habitual breakfast eaters. It’s possible that those who don’t normally eat breakfast would experience different results.

This article was originally posted by Ryan at the original HillRunner.com Blogs.

Gluten free diet for the non-celiac

I’ve noticed that quite a few people over the past few years are going toward gluten free diets, even if they are non-celiac. The belief apparently is that, even for non-celiacs, there are benefits to avoiding gluten.

Well, maybe not:

A short-term GFD had no overall effect on performance, GI symptoms, well-being, and a select indicator of intestinal injury or inflammatory markers in non-celiac endurance athletes.

As usual, more study is needed. However, at least in the short term, this study suggests no benefit in any regard that was measured. Seeing as I’m not aware of any studies that suggest otherwise, at this time at least, I’m going to keep having my gluten.

Why do older runners struggle more in the heat?

We’ve known for some time that older runners seem to get hit harder by the heat than younger runners. What I haven’t noticed much on, though, is why. This is an interesting question because, if we understand why, maybe we will be able to find some ways to lessen the effect.

Well, this was spun as informing us that older runners do struggle more in the heat but another part caught my attention:

"[A]ge was the only variable to significantly correlate with whole-body sweat rate," the researchers wrote. "This would suggest that when the stimulus for sweating is equal for all participants … aging may have a larger influence on whole-body heat loss capacity than the fitness level or specific physical characteristics of the individual."

So our sweat rate declines as we age, even independent of variables that we usually think of as affecting sweat rate such as fitness or body fat percentage.

Knowing that sweating is our primary way to dissipate body heat, this is a big deal. Next up: why does our sweat rate decrease as we age? It appears we don’t yet have an answer to that.