Rhonda: So this kind of reminds me of...I've heard you talk about the sprint from danger sort of pace or intensity and how...I mean, you know, that could be basically the cornerstone of a highly efficient workout. Now, what is that? Can you talk about that and then maybe compare it to the Wingate or maybe even the sprint interval training differences?

Dr. Gibala: No, for sure. So again, you know, people think VO2 max will...and max is max. How can you be above max? But when we talk about VO2 max, that's maximum aerobic capacity and then we could have metrics to that. So peak power, work peak at VO2 max. But sprint from danger pace is just that. So if you had to flee a burning building, the pace you might run at to save your child from an oncoming car, it's well above VO2 max.

But you might only have to do it for five seconds. So it would equate to top running speed, an all-out sprint over five or 10 seconds. You know, even a Wingate test is not true max power output. The highest power outputs during a Wingate usually occur within the first few seconds. So we're talking five to 10 second efforts.

What's the highest work rate that you could put out? What's the highest amount of ATP that you could generate, much of it non-oxidatively, over a 5-, a 10-second effort at most? That's sprint from danger pace. And you know, if you're an athlete, you know, we hear these five zone training, six zone training.

For many of us, three zones are enough. But when we talk about five and six zone, what that often is referring to is discriminating work rates or power outputs above VO2 max. And if you're the athlete looking to optimize performance, you know, whether you're working at 150% of VO2 max, which you might be able to do for a minute or two, or you're working at 250, 300% of VO2 max for five or 10 seconds, those might be important in terms of discriminating fine changes that could further support your performance. Whereas for most of us, it doesn't really matter. We don't need to get that level of sensitivity in terms of how we structure our training at these very, very high intensities or work rates.

Rhonda: So do you think there would... I mean, like, could there be a benefit for sort of changing around our training protocol to incorporate some of that sprint? I mean, VO2 max benefit or, you know...

Dr. Gibala: So I do. And again, this is not scientific, but it makes sense to me at least. And it's the old investing analogy, right? And so you can hit a home run with a hot stock tip, but for most people, they're better off to spread it around, put your eggs in different baskets. And so I think when it comes to exercise training, for many individuals, there's an analogy and that's it. Maybe do different types of training. And that's gonna... so whether you're someone who really responds to sprint training or really responds to moderate, we can't necessarily predict that. And so varying up your training, just like we spread out our risk when we invest, might be the best approach. So should individuals engage in some short, sharp, hard efforts?

I think, ideally speaking, yes, they should. There's even some recent evidence, I think there's renewed interest in the potential for elite endurance athletes to incorporate sprinting in their training. And there's a series of studies that's come out, Rønnestad, Carsten Lundby's work showing that when truly world-class level cyclists, we throw these terms around, highly trained, elite, these are cyclists with starting VO2 max values, 72, 73 mls per kilogram per minute.

And they randomized them to do either traditional HIIT, four, five minute repeats, or effort matched 30 second sprints. And they sort of effort matched, so whichever group you're assigned to, you're working at the highest effort you could, and they were work matched. And what they found was the group that incorporated the sprints had a further boost to their performance, 20 minute time trial performance.

And they actually had a small but significant improvement in VO2 max. And so it would suggest that maybe there might be a place for athletes to incorporate what some call RSTs, repeated sprint training, as a ways to further augment their performance. Now, still relatively small, three week interventions, but to go back to your question, I think there is a place for incorporating very vigorous effort sometimes.

Again, there's some people who shouldn't do sprinting, especially if you're starting out. But all things being equal, yeah, I think varying up your approach is gonna be the best for general fitness.