Thirsty (for knowledge) Thursday: Better to Run FASTER or FARTHER?

Outside Magazine recently wrote an article about a study found in the Journal of Physiology. It looks at that simple question of wanting to be better: should you train HARDER, or should you train MORE?

The authors of the study offered contrasting claims to the point "exercise training intensity is more important than volume to promote increases in human skeletal muscle mitochondrial content:"

The amount of mitochondria in your muscles is the most important adaptation that occurs in response to endurance training, so the debate was effectively about whether running faster or running longer is the best way to boost your endurance.

The researchers arguing in favor of INTENSITY had 2 main claims:

First, that when you compare training programs where subjects do an equal amount of total work, those who train at a higher intensity and lower volume see the biggest gains in mitochondria; and second, that in the real world intensity is the most important variable because the vast majority of people are unwilling to spend long periods of time doing high-volume training anyway.

The other group arguing in favor of VOLUME of training cited:

...a combined analysis of 56 studies that suggests a robust relationship between total training volume and mitochondrial changes. The same analysis didn’t find any significant relationship between training intensity and mitochondrial changes, suggesting that volume is really the key variable.

Each group made their points, and then offered a rebuttal of the other group's points. (This sounds like a debate team, and I love it.) They had a few points worth noting: how they measured the mitochondrial changes, and if it's the same in humans as in rodents. The VOLUME group conceded that "higher-intensity exercise will give you a greater mitochondrial response per minute of exercise." The group for INTENSITY made this a crucial point: "in a time-pressed world, getting more fitness per minute spent working out is important to enable more people to meet their fitness goals."

But to the VOLUME group, "efficiency and effectiveness are two different things. In the context of competitive sports, the contest is to see who is fastest, not who spent the least amount of time training." And others have questioned whether "lack of time is really a significant barrier, or whether it’s just a convenient excuse for avoiding something perceived as unpleasant."

The article doesn't make it a point to crown a one-sided winner in this debate:

It reminds of me an an example Mayo Clinic physiologist Michael Joyner sometimes cites: the final of the men’s 5,000 meters at the 1964 Tokyo Olympics. The race was won by Bob Schul, who trained pretty much exclusively with twice-a-day interval workouts. The runner-up was Harald Norpoth, who relied on well over 100 miles a week of long, slow distance. Bronze went to Bill Dellinger, who later coached at the University of Oregon and did a mix of intervals and longer, slower runs. Exactly one second separated the three men. As a bonus, also in the race was Ron Clarke, who did mostly medium-paced runs that we would now call threshold training.

One lesson to take from that race is that there are many roads leading to the same podium. [The two research] groups agree that intensity and volume are both effective at triggering mitochondrial adaptations and improving endurance. Which one you see as most important probably depends on your goals (winning races, improving health) and personal preferences. Some people love long, relaxed runs, rides, or hikes; others love the adrenaline of pushing hard, or simply want to get it over with. At the high end, if you push either intensity or volume to sufficient extremes, Joyner suggests, you can probably more or less max out the physiological adaptations you’re capable of getting with either approach.

So sorry, no clear winner. It's just best to do bits of everything. As the article says, "doing the same thing over and over again will eventually produce diminishing returns — or drive you nuts."

For more "Thirsty Thursday" posts that highlight workouts, body science, and all kinds of interesting information, CLICK HERE. As always, back with some "Friday Funnies" tomorrow.