It’s more a matter of what will have more of a negative impact on the subsequent work. I guess it depends on the rest of your workout. Doing the sprint 8 at the beginning of an upper body session would likely not lead to too much of a decrease in performance, at least not due to local fatigue.
You could argue that if I train lower body before, the sprint 8 performance will decrease… but you’ll notice that I did not recommend doing them on the lower body days.
Here is my reasoning for putting them first:
Have you ever done a Wingate test? A Wingate test is one of the most unpleasant thing you can do. It’s 30 seconds ALL-OUT on a stationary bike with high resistance. It’s done to measure peak power output.
I’ve seen athletes who were in good shape THROW UP after an all-out Wingate test. I myself felt like crap for about 20 minutes afterwards.
Sprint 8 is very similar to the Wingate test. The fact that there is no resistance and that you might go to 90-95% instead of 100% when you have the motivation of a test, leads to less of a systemic impact as the Wingate test… but you are doing 6-8 sets, which will leave you drained neurologically. You will feel suboptimal for a pretty long time afterwards. And even if your upper body is “rested” the fact that you feel “off” will hurt your strength performance.
And it’s not just a matter of being in good shape either. In fact, the more powerful athletes might have.a much greater systemic fatigue from doing all-out work for 30-45 seconds than someone who is not in great shape… simply because they can produce so much output.
I’ve trained with national level sprinters who would be brain dead for an hour after doing six 100m sprints in a workout.
if you can feel great and energized enough to do an intense workout after a sprint 8 session you are either not pushing hard enough (which defeats the purpose) or your are a highly trained athlete, used to the lactate zone… in which case you would not be doing sprint 8 in the first place because you would already be doing a boatload of lactic work in your program and sprint 8 would be redundant.
As for the GH comment, that is a gross misunderstanding of what it does in the body. Increasing GH before lifting will not make you stronger or perform better. And increasing it at the end of the workout will lead to the same effects when it comes to recovery. Anyway, transient changes in hormone levels don’t really have much of an impact on actual results. Heck, inject 2-4IU of growth hormone (more than a sprint 8 workout will give you) and it will have pretty much no impact on muscle growth or strength.
But my best recommendation is TRY IT. Do an honest to God, ‘by the book’, sprint 8 session. Go all out like your life dependant on it for 45 seconds with a moderate rest period and let me know if you feel like lifting hard afterwards!
And BTW, even though the “doing the most neurologically demanding work first” makes sense in theory, it is not always effective. Take the deadlift: if you have 5 HEAVY sets of 5 sets on the deadlift to do, going to your limit or close, I guarantee that the rest of the workout will suffer if you do them at the beginning of the workout.