Holloszy's rats contradicts running singles. Physiologists?

i don't think that assuming 3 x 31% = 93% is a valid assumption. what they really need to do is do another study with rats running 120 min per day, broken up into 4, 3, 2, and 1 workout and compare those results.

finishing a freshman exercise phys class? that study has been around and around forever it seems...

i doesn't contradict running singles, rather it supports incorporating variable training methods at variable speeds/times/intensities for ideal training

that's why running 200s and running 20 miles may all be important at some point in training

risk of injury...im at a risk for injury by not running. im also at a risk by training. Your most likely at a greater risk for overtraining if you were doing 3x30min per day over time because of the increased intensity and decreased recovery time between runs. The possibility of staleness would negate the potential benefits. but in the same way, doing singles everyday can have the same effect (always tired, slow gear,etc). thats why you mix it up.

Not sure whether the 60 min measurement is off or the 120 min measurement. Dudley found that cytochrome c levels plateaued with respect to time (Dudley 1982 JAP 53(4):844-50).

You can't just add percentages like that. Also this doesn't contradict or show anything wrt doubles, since the study didn't have the rats doubling.

Good idea. Perhaps letsrun could sponsor such a study. There's surely enough interest around these parts.

Two thoughts (not having read the publication):

1. If 120min is the peak tested, how do you know 120 is the best? Maybe 240min is better, but not as good as 360min. Would anyone be shocked by a causal relationship between time and mitochondria?

2. Rat physiology isn't the same as human physiology. There ought to be enough human* data to do this same study, even as a meta-analysis.

* I hate seeing studies done with 8-12 cyclists riding to max on two separate occasions and concluding blah blah blah. Start doing those studies with 80 people and I'll believe they have statistically significant conclusions.

I don't think that you can really draw those conclusions. For instance, why would you assume that running three times 30 minutes would give you 31% each time? It seems like there would be some diminishing returns. Maybe those last few percent are difficult to attain, and long runs are important to squeeze out that last bit of improvement.

How fast could those rats run a 5K?

Procrastinator wrote:

Not sure whether the 60 min measurement is off or the 120 min measurement. Dudley found that cytochrome c levels plateaued with respect to time (Dudley 1982 JAP 53(4):844-50).

In fact, the chart on this site i found (

) seems to imply that running more than 60 minutes actually has less use (total increase in cytochrome c), at least in soleus. Perhaps malmo is on to something? A lot of elites seem to run doubles ranging 45-60 minutes per run, long runs excluded.

The real question is wrote:

How fast could those rats run a 5K?

"and training intensity

was fixed at about 1.2 mph (or about 32 metres per minute and 313 minutes for the 10K, which

is an intensity of around 50- to 60-per cent VO2max for a healthy lab rat)."

Assuming 55 %vo2max, this means ~61% vvo2max.

Assume first prediction 133/(85/55) --> 86 minutes. Look up 86minutes vvo2max in Daniels running formule --> funnily enough 86%vvo2max is sustainable for 86 minutes.

Conclusion: the rats can theoretically run a 5K all-out in 133/(86/61) = 94:20, or 18:51/km, 30:11/mile.

I doubt that it works the same with those rats as it works for humans though. Just estimating something.

Note that other people have had much different results where there was no benefit of going over 1 hours.

I read two studies that involved rats, and both found that running beyond 40 minutes didn't lead to additional increase in cytochrome C.

Perhaps all of the transcription factors or some other genetic factor get occupied within the first 40 minutes.

When it comes to mitochondria development, perhaps it is better to do 3 40 minute runs a day rather than 2 60 minute runs.

OBN wrote:

I read two studies that involved rats, and both found that running beyond 40 minutes didn't lead to additional increase in cytochrome C.

Perhaps all of the transcription factors or some other genetic factor get occupied within the first 40 minutes.

When it comes to mitochondria development, perhaps it is better to do 3 40 minute runs a day rather than 2 60 minute runs.

It seems so. However, there may be other factors that contribute to performance like running efficiency. Perhaps running long enhances performance this way.

Perhaps a whole list of other things too? I don't know how much cytochrome C alone says, really.