VO2 max calculations while running with 20lb pack - anyway to compensate?

Bear in mind that VO2 is measured in ml/min/kg. Therefore if you change your body weight then the calculations will be thrown out. Aside from that, your intensity will be higher with that extra 20lb than without, which should be reflected in an increased heart rate for the same velocity without the pack.

It's not necessarily going to throw out the analytics, but it will change the results. Overall, it probably does not matter.

A comment on

The ONLY way to get my base mileage in is to run to work (24/miles/week) with ~20lb pack.

The only way to increase base mileage is to increase base mileage. Training for ultras is more about time on your feet primarily, than strength per se. What you're doing with that pack is increasing the effort, training the strength. That's not the same as increasing mileage. It will make you stronger but an ultra is about strength + endurance. You need to work on both. Strength on hills carrying loads. Endurance through time on your feet.

Yes, the 20 lbs will throw out the V02Max analytics.

To deal with this, I'd suggest logging your pack runs as Trail Runs on your F5. Trail Running will still calculate Training Load and Training Effect, but it won't affect your V02Max. As long as you do a run without a pack (and log it as Running) once a week or so, the watch will retain a current VO2Max on which it can base everything else off.

What you're doing with that pack is increasing the effort, training the strength. That's not the same as increasing mileage.

I think you are misunderstanding the OP. He is not carrying the pack for any training purpose. He is carrying the pack because he need it at his workplace. So if his only way of getting the mileage is by running to his workplace, he is forced to bring the pack on those runs.

Anyway, I am growing concerned that the extra 20lbs I'm forced to run with every morning is going to throw off all of the calculations. For example, I did a long run this weekend (w/o pack) and my VO2 max went up 2 points.

Any suggestions? Does anyone think that this extra weight most mornings is going to entirely throw off all of the analytics? Or will the long weekend runs be enough to compensate?

Thanks for any advice.

Hi JICM,

Most everything above is already on point, but I'll throw my 0.02 in as well.

Yes, doing substantial part of your running with a 20lb pack is going to impact your VO2max calc. The reason is pretty simple. With the added weight, your body is forced to work quite a bit harder to produce the same external work (running speed) - which is the primary basis for calculating your VO2max.

This has the knock-on effect of impacting your Training Status feedback - because Training Status is primarily looking at your Training Load in light of changes in your VO2max. So, if your VO2max is getting knocked around because of the time you spend trucking around with an extra 20lbs on your back, then the Training Status feedback is going to be out of kilt, as well.

The good news is that your Training Load, Training Effects (aerobic and anaerobic), etc should accumulate just fine will accurately reflect the real load you are placing on your body and the resulting anticipated performance capacity development.

This means that as long as your filter the "extra weight" sessions out of your data by classifying them as Trail Runs, as suggested by others above, then you can keep both your VO2max and Training Status on track and reflecting your actual real status.

Have fun and good luck with the rest of your training.

I have a similar (minor) issue with my stroller runs. It would be a nice idea to be able to specify "gear weight" and make the watch factor that into training load calculations.

Well, Training Load is essentially a description of degree of homeostasis disturbance, measured in terms of predicted excess post-exercise oxygen consumption (EPOC). That oxygen consumption above what your body would normal use is a marker that some sort of restorative/adaptive work is being done.

With that in mind, it's a measure of "internal workload" - as opposed to "external workload" which is where something like gear weight, movement speed, etc would play a role.

In a nutshell, Training Load and by extension Training Effect accumulation are activity agnostic and will accumulate based on how hard your body is working to perform whatever activity or variation of that activity you are performing.

I have a similar (minor) issue with my stroller runs. It would be a nice idea to be able to specify "gear weight" and make the watch factor that into training load calculations.

Gear weight in a stroller will have dramatically less effect than the same weight carried in a backpack.

Training load calculations (other than VO2Max) will still pick up any extra effort involved through a slightly increased heart rate - no adjustment to the watch settings is required.