Back in the day, the importance of a distance run was thought to be that of putting constant pressure on the heart so that it will adapt. In other words the theory went that you wanted to keep your heart rate up for a prolonged period. So the logic went, the further we can go the better.
What we now know is that adapting to training is a super complicated process that involves numerous different adaptations on multiple different systems. So is it as easy as more is always better? I’ve delved into this question many times in regards to doubles versus singles. By the old school logic, singles should always be better. It makes logical sense that 10 miles once is better than 5 miles twice. But as I pointed out before, that logic isn’t always sound. It’s one of my favorite topics to delve into (more here) and it’s always worth looking into.
An interesting new study came out where they took a look at the effect of one 30min run versus 3x10min runs throughout the day in mice. It’s not quite your doubles versus singles argument, but it’s an interesting concept.
What makes the research a bit more fascinating (and also harder to translate to real world application) is that it was on mice, which means they could dissect and analyze all sorts of things that we normally can’t see. We get to see what is going on at the cellular level instead of relying on crappy surrogate markers like VO2max.
What they did was take mice and stick them on an 8 week treadmill training regime. Half the group they had do 30min a day all at once 5x a week, while the others did 3x10min split with 2 hours rest in between. Then they measured all sorts of lovely signaling pathways activation to see what was going on.
What did they find?