In Episode 3 of the Athletes Compass podcast, hosts Paul Warloski, Marjaana Rakai and Dr. Paul Laursen, delve into advanced strategies for high-intensity interval training (HIIT). They address a triathlete’s question about the best ways to structure HIIT workouts, discussing the progression of interval lengths, the importance of workout reserves, and the nuances of active vs. passive recovery. The hosts also debunk common HIIT myths, such as the necessity of intense pain for gains, and emphasize the importance of personalized training approaches. The episode provides valuable insights for both novice and seasoned athletes looking to optimize their HIIT routines.

Key Episode Takeaways

  • Progression in HIIT: Gradually increasing interval lengths can be beneficial, but it’s important to tailor this to individual fitness levels and preferences.
  • Workout Reserve: Utilizing Athletica’s workout reserve feature can help athletes monitor their training load and avoid overtraining.
  • Recovery Strategies: Passive recovery is more effective than active recovery for replenishing oxygen and preparing for subsequent intervals.
  • Warm-Up Techniques: A progressive warm-up, including some strides and accelerations, helps in achieving better performance during HIIT.
  • Misconceptions about HIIT: Effective HIIT doesn’t necessarily involve extreme pain; it’s more about smart, sustainable training.
  • Role of RPE: Understanding Rate of Perceived Effort (RPE) can guide training intensity better than fixed power targets.
  • Starting HIIT: Beginners should start with manageable intervals, like 30-30s, and gradually progress as they build endurance and strength.
  • Readiness for HIIT: Ensuring overall fitness and health before starting HIIT is crucial to avoid injury and excessive fatigue.



Paul Warloski (00:37)

and welcome to the Athletes Compass Podcast where we navigate training, fitness, and health for everyday athletes. Today is the third and last podcast where we are talking about high intensity interval training or HIIT.

Paul Laursen (00:49)

Oh, Paul, it's not going to be the last. Come on, mate. Yes.

Paul Warloski (00:53)

Okay, you're right. It's going to be the last of this series. So if you haven't listened to the first two, please go back, listen to them. Starting with the first one is the Prof, Dr. Paul Laursen He explains the science behind HIIT and then last time we did more practical information about phenotypes in 3030s and 4 -2s threshold workouts. But today we are getting into a question from our friend, Sophie.

Marjaana Rakai (01:23)

Sophie, who we assume is a triathlete, based on her questions coming up, she asked a series of high intensity interval training questions on Athletica Forum, which we thought would be good to end our HIIT series this time. Her question is, I know there's no right way to skin this cat. In your opinion, does it make sense to build interval lengths over the week, such as increasing the length from two to four minutes on the bike?

over the course of several weeks? Or does starting with the four minutes give the biggest bang for buck regarding time at VO2 max? Or is it better to start with two minutes as I haven't done these intervals for a long time?

Paul Laursen (02:09)

Yeah, awesome. Great questions. Sophie hope your training is going well girl and like yeah, you know, there's no right way to skin the cat and Look, I think this is a this one makes a lot of sense I think like it sounds like you're you know, you're you're almost playing with your own intuition based on your Your mind is it's so interesting how your mind kind of knows what it can

and can't do or should and shouldn't do. And I like the formula that you're kind of going about here where you're starting with like two minutes might be more manageable for you in terms of like a progression. Like, and say you're gonna do, I don't know, six by two minutes, right? And that might be a perfect little starting place. And then the next week might be, yeah, six,

you know, six by three minutes and then six by four minutes or whatever the case may be. It's really helpful when we, you know, we get a plan like that. And there is no right or wrong way to sort of do these sorts of things, but those are great sort of strategies that we can kind of go about these things. You know, I think Sophie is a little bit more of a diesel athlete compared to a twitchy athlete. So this is probably why she's,

She's playing around in her mind, around progressing her longer intervals. Remember in the last podcast, we were kind of comparing a lot of short intervals versus long intervals. And I think Sophie is certainly the diesel case study here where, yeah, she's pretty keen on doing long intervals for her context. So yeah, just to kick things off, that's...

That's a great, great way to go things. And the only other thing I would add now, Sophie, is to really start getting a handle on Athletica's workout reserve because it can really help with knowing what you've been exposed to. It really looks at your exposure time on any of these intensity versus duration bandwidths. It's reflecting on...

your power profile and what that is over the last six weeks. And that's in pace or that's in running, right? So just go to your charts. That's what Athletica sees. Remember, we have these now also. The great Phil Whitehurst on the Athletica Forum is our Garmin app developer. And he has put this on for everyone to use in real time.

on their watches, on their Garmin head units, and you can actually see what your exposure is at in terms of that reserve. And you know that if you're starting to get down towards zero or going into negative reserves, well, you're in uncharted territories in terms of the external load that you're pushing, whether that's running speed or that is power on the bike. And...

when you start getting into those zeros or negatives, you need to start thinking about easing up and giving some recovery to HIIT it again or to call it a day at the end of it, if that's there. So we spoke about this in the last podcast where that's really the answer to all of these questions often comes down to you as an individual. There's no right or wrong answer.

for any number of reps that you do, how long these reps you do, whether it's short or long, it often comes down to you and what you've been exposed to. Remember, we're always... The most important session is the next session, and we want to continue to build that up from one session to the next so that we're progressively overloading the system and we reach these new heights.

Marjaana Rakai (06:04)

Talking about what we've been exposed to.

Let's talk about recovery, like the recovery intervals in between. Let's say 30 30s, you have 30 seconds of recovery. What's the ideal way of recovery?

Paul Warloski (06:36)

Thank you.

Paul Laursen (06:45)

Yeah, so that is a million dollar question. That is just, I don't know if it's a million dollar question, it's a very important question, Marjaana and it's, we're talking about what is the most important part of a HIIT session? It's the work interval. It's the work rep. So how do you maximize your effort in the work rep? Do you do, you you know

recovery so that you flush out the blood lactate or do you do almost nothing or towards nothing at least so that you don't take away any oxygen in that muscle cell itself that's going to be you know in you know really important for replenishing that which is in the myoglobin around the muscle so that it can you know

use aerobic metabolism to make more energy for you? And the answer is, it's not about, we've learned now, it's not about flushing out lactate per se, it's about conserving oxygen and allowing that myoglobin to replete itself. And that means passive effort. I mean, it's doing nothing, towards nothing, right? Like just turning the legs over just effortlessly. And that is the best way to recover.

from either a short interval or a long interval. You want to do just about nothing. So Steven Seiler, one of his key papers when he was looking at recovery, two minutes of walking. If you're a running athlete and you're about two minutes of walking almost maximally recovers everything that you need between your efforts. That comes from the guru, prof,

Prof. Steven Seiler. So, and then, yeah, with respect to short intervals, often, you know, like say a 30 -30, again, keeping it just dead easy. When I'm doing 30 -30s on my bike, it's just like really, really just barely moving my legs over kind of thing because I'm ready to really rip into the next 30 effort, 30 -second effort. And I know that if I'm going to be doing active recovery on that, I'm taking,

Paul Warloski (08:44)


Paul Laursen (09:07)

I'm taking oxygen away from my ability to replete the myoglobin and give me resource and reserve for the next effort. Speaking of reserve, you can actually see that right on your workout reserve. If you want to prove this for yourself, check out your workout reserve numbers and compare yourself to an active versus a passive recovery. You'll see that in the passive recovery phase,

Your workout reserve is shooting back up towards the roof. That's what you

Marjaana Rakai (09:37)

God bless our old PE teachers. But they exposed us to something that I know everybody can relate to. And that's recovery. Hands over your head. Keep walking.

Paul Warloski (09:41)

Thank you.

Paul Laursen (09:41)

Ha ha!

Paul Warloski (09:49)

Per block.

Marjaana Rakai (09:54)


Paul Laursen (09:54)

Yeah, what was the rationale there?

Paul Warloski (09:59)

Something get opened.

Marjaana Rakai (10:00)

I've heard this is something that annoys me so much. Kids track and field meet or baseball, whatever. Wherever I see this is I'm just on the sidelines. I've heard that when you put your arms around behind your head it opens up your chest but what it's doing it's closing off your lungs. Part of your lungs is at the backside, right? So it closes it off.

Paul Laursen (10:20)



Marjaana Rakai (10:29)

Plus you're working against gravity, like your heart needs to pump harder to push that oxygen. Like if you listen to your body, and this is what I teach my kids, if you listen to your body, you want to put your hands on the knees and bend over, right?

Paul Laursen (10:47)

They did a study on that.

Marjaana Rakai (10:48)

us that hands on the knees were better for recovery.

Paul Laursen (10:48)

What do you think they shared?

Yeah, correct. That's what they showed.

Yeah. Perceived recovery was better with hands on knees. So again, yeah, it was totally contrary to tradition. And this is like just a huge issue. So we just, tradition always rules, right? And this is why we can never take anything for granted, even the things that we're telling you here right now, whether it's,

Marjaana Rakai (10:56)


Paul Laursen (11:22)

whether it's HIIT science or it's athletic, this is what we know now, but we better be darn ready to switch our views and open to switch our views if in fact the data or our intuition kind of changes, right? And we can't be fixed in these sorts of mindsets because they don't serve us well to do that, right? Or we're always going to be doing this in active recovery for the rest of our lives. And that's not the way to be.

So yeah, but it's rampant in sport, right? And it's ego. Martin speaks, Martin, my colleague at HIIT Science, he speaks about this all the time. We see this in sports at the highest level. It's just like, you know, the coaches that make there, the athletes that make it there, egos, they have very, very powerful and strong egos because it's an important element that elicits high performance,

but it doesn't always serve us well to make change. So it's such an interesting topic you bring up there, Marjaana.

Paul Warloski (12:27)

This is kind of awkward to do on the bike too, I'm telling you, I want you to ride. All right, Sophie next asks, how would you change interval duration and intensity for a more slow diesel kind of athlete like Sophie? Would you prescribe the shorter intervals for slower athletes to improve their MAP, maximal aerobic power, or.

and longer intervals for more explosive athletes to build their aerobic power and reduce glycolytic action. So this is something we kind of talked about in the last episode, but she brought into some pieces that we should probably address with MAP and glycolytic actions. So there's a, what is MAP and how do shorter intervals improve it?

Paul Laursen (13:15)

Yeah, well again, we did bring we did mention this so map is maximal aerobic power. So, you know, it's like your VO2 max power on the bike, it's would be analogous to kind of your your four or five minute power and.

Look, again, if we think about the study that we mentioned with Nicky Onquist and Bent Rolstad, that's on the HIIT Science website in a blog form, it's really easily digestible for all. And it is basically they showed that you get more bang for buck with in a group of 13, I think it was 13 elite to highly trained cyclists.

The short intervals were still working for those athletes. They were a mixed group, probably a blend of diesels and hybrid athletes. You just continue to progress, probably set numbers.

If you're doing a 30 -30, you might start with three to four sets of these eight 30 -30s with three minutes rest in between. And then you would potentially add another set and add another set until you move up to six is probably getting to be enough. But remember, each time you do one of those sets, Sophie, you are...

you're probably trying to get a slightly greater mean average power across those sets. So say you're doing them at 350, you might be working towards going 355 mean on the next one, and then 360, 370, etc. until you're almost towards 400, whatever number it is for you kind of thing. So as you add...

set number and you add more power, this is why we want to have these sets open if possible, not fixed in erg mode, but if we have these open, then it's really... we're allowing our brain to elicit that added power output if it can do it. Or pull back if need be as well and save it for another day. So, yeah, that would be...

Again, I think we spoke about this last time when Old was kind of asking the question around, and he was bringing in both his 30 -30s and early in the week, and he was talking about his four -minute efforts later in the week. Both were great for a cyclist where he's kind of had both in there. So lots of ways just going to, you need to be careful with a triathlete because you've got the other sports and whatnot are in there as well. So, you know, context always, you got to, yeah, you know, that's where, if we're just talking about bike,

then 30 -30 might be nice, just HIIT that kind of once. You don't need to also HIIT that with a four -minute effort because you might be getting that also already in your swim workout or in your running workout, right? So context always, never one right way to do these things. It's all about you, Sophie, or you the listener. So what level are you at? And...

How can you leverage the tools at your disposal like workout reserves so you see individually where you're at with all these sorts of things and then progress to your level accordingly.

Marjaana Rakai (17:00)

You mentioned ERG mode. See, you would recommend not using ERG mode on your HIIT sessions.

Paul Laursen (17:08)

You know, I think erg mode is fantastic when you're starting out and you just, because you don't really, you're a little lost, you know, in terms of what hitting the right intensity is. So erg mode, I think is really good and early on in the piece because then you can just go through the motion and it takes all the dress workout. When we're talking about erg mode, where like basically you can plug in your athletic workout into,

whether it be TrainerRoad or Zwift, or you name your platform, you plug it in there, and that's the power that you kind of have to ride on the trainer type that you have. So that's fantastic. And then it's just like, again, there's no guesswork. That's the power I need to ride. That's the external workload. And it'll be what it'll be. And if I fail, then I fail. I can't do the last sort of sets. That's fine. But at least I'm learning. And so really good in the beginning just to learn what that...

and pace sort of feels. But then as you become a more experienced athlete, then it's a great idea to switch it up and go to open mode or free ride or whatever it might be called on your platform of choice. And now you're trusting in your mind and you're learning in your mind. Now you're sort of trying to target this power. You might also do this in the open road if you have a power meter and you're keeping an eye on the power numbers.

But now you're just, maybe you might want to test going a little bit harder than what was prescribed. Or if you're really, again, if it's not so good, then maybe you're failing a bit and we're down a little bit. But that's really good to play with. And then if we take the most experienced athletes, and now I'm reflecting on high profile athletes like,

that I've coached like Kyle and Andy, athletic ambassador. They're so well conditioned mentally and physically that they just dial directly into that power and they can repeat it. They have the whole, we talked about last time, the neuromuscular programming and stuff, right? So their mind is totally dialed in precisely.

to what actually has to be done there from the power output perspective. And their first repetition is exactly the same as their last repetition. And the only thing that really steps up might be the heart rate a little bit from the first to the end as it's there to meet it. And then they turn away and they call it at the end of the day. So that's what we're striving for at the end, but we don't get there right off the, you know, that's not gonna happen on day one.

So there's a nice little, hopefully you can see a nice little progression there, Paul, from erg mode to really dialing in the neuromuscular, sorry, just like the mind to body output connection kind of thing that you would get towards the end as a seasoned athlete.

Marjaana Rakai (20:18)

Awesome. To finish off Sophie's questions, let's talk about warm -up. In order to accumulate the most time at VO2 marks, what would be a good warm -up? I thought I would do a progressive warm -up with a few strides and acceleration. I assume this is running. For example, six minutes easy, then six minutes at the first threshold, three minutes at the second threshold, and then three minutes easy. Then I would do the 30 -30 workout.

What is a good warm -up for HIIT sessions?

Paul Warloski (20:50)


Paul Laursen (20:50)

Yeah, I don't overthink this one. I think there's always lots of ways to sort of skin it. And I think you can even get away with making the first set of 3030s as a little bit of your warm -up too, right? So this is when I'm, say I'm gonna do four to six sets of these 3030s.

I don't care too, too much. I'm not going to overly stress myself if my first set of 3030s isn't amazing. I'm sorry, but I'm just not. Well, at least that's the level I'm at where I don't worry too, too much about that. If I'm 50 watts below what set 2, 3, 4, 5 is going to be at, because I'm getting this priming effect, this warm -up effect.

where there's something called the Q10 effect where when the muscle cells actually warm, they actually start firing better. So you get this efficiency kind of thing happening. And that just takes time. But I think the way she's described that there, whereas you definitely want to have something easy, I wouldn't probably go straight into the 3030s without at least warming up a little bit.

I do a couple surges maybe too. And where it's like, and even if it's really, really short, like I might even just do one or two, like 30 second reps and with two minutes between them kind of thing. But at least I've engaged for 30 seconds and I've started to breathe a little bit harder. And then I'm kind of ready to go. So.

Yeah, I wouldn't overthink the warm up too, too much, but it is good to be warm. And you'll especially need this too, if you happen to be going through a little bit of a period of fatigue, fatigue be that kind of from work, stress, life, then it finds that it takes me a little bit longer to warm up as well for that. Marjaana's smiling, I'm sure she can relate.

Paul Warloski (23:09)

Thank you.

Marjaana Rakai (23:11)

Yeah. And as I age, I find like I need a little bit more warmup. 10 minutes is not enough anymore. I've added another 10. So 20 minute warmup easy is good. If I'm running, I like to have some strides in there. And also, you know, I've been doing strength work first and then doing my bike HIIT session that I love to do that. But I think...

as we age and especially if we do it in running, it's good to have those long warm -up and then hit those fast twitch muscles with some strides with plenty of recovery in between and then use the first set as a warm -up.

Paul Laursen (23:54)

Yeah, and I'm also like, I'm rereading the question again, Sophie, sorry, I might've missed this a little bit, but you know, you're really, I can see you're fixated on accumulating more time at VO2Max, whether that's, you know, an important thing or not. We don't totally know, it may be an important factor, but the jury is sort of still out on that. And...

Yeah, but for sure, if you want to accumulate more time at VO2Max, then you're going to want to have some sort of a VO2 priming effect in there. And again, if I'm going to be really picky, I would say you might want to do... you've only mentioned three minutes at second threshold. You might want to do a little bit time over threshold so that you speed the VO2 slow component. And...

And then, so that yeah, those larger Fast Twitch fibers are a little bit more primed and ready to go. But yeah, again, yeah, these are, you know, small little things that, yeah, you know, I'm not sure if these are big rocks. I think you can skin this one a lot of different ways and probably get it come out the same outcome.

getting the workout done. If you can get in and get that workout done. But whether it's done with that first set perfect or not, that's the only thing that's really going to be potentially jeopardized is the very first set. If you do one set of 30 -30s, you're primed for the second set, which is kind of where I sort of started. And you know,

Paul Warloski (25:35)

Thank you.

Paul Laursen (25:36)

whether I achieved that much time at VO2 Max on my first set of 30 -30s or not, I'm not sure if that's going to be what makes me the better athlete at the end of the day. What for me is going to be more important on is consistent training day in and day out, hitting my

Paul Warloski (25:57)

So Paul and Marjaana, we had some final short questions about HIIT workouts in general. Are there any misconceptions about HIIT? I'm sure Paul, you've heard a lot of them since you published your book that you frequently encounter. Can you debunk any myths surrounding effectiveness or safety?

Paul Laursen (26:16)

the biggest one is it's not about pain, no pain, no gain. That's the biggest misconception. When someone says HIIT, they immediately, at least the average person, not the HIIT science follower or the Athletica follower, but anyone that's outside of this area or who doesn't follow Steven Seiler, then they'll be thinking that HIIT, a HIIT workout is more like the crossfit and you'd better be flogged.

and dead at the end of it. And that's never, it was never what the coaches that were designing high intensity interval training for Olympians in the earlier, you know, 30s, 40s and 50s. It's never what they had in mind, but, and you know, nothing against CrossFit. It's got its place, it's great, but it's like that kind of that, you know, what is it, orange theory and these sorts of things. There's just this movement that you've got to kind of kill yourself.

And that's just not really sustainable. That creates a stress that can be, you got to be careful with, right? Certainly can make you injured or run down. So I'll say that's my biggest one, Paul.

Marjaana Rakai (27:28)

the importance of understanding RPE, like your Rate of Perceive effort, because it comes in so handy when you're at least when you're learning to do interval work and use RPE instead of focusing too much on your power and, you know, blindly go by, oh, I need to do

30 -30 is between 300 and 320, which I used to do. I knew the target and I was trying to stay within there. And then along comes the prof and says, well, keep it open. Like, you know your target, but keep it open. Don't think about the upper limit. Like you're limiting yourself if you're thinking, this is where I'm going to hit it today. Because your body doesn't really know.

the numbers. Your body knows how hard this effort is feeling to you. And then you can work on your mental mindset. Okay, do I have one more? Do I have one? Maybe two more. Okay, maybe it's time to say bye bye to this HIIT set today. I feel like I'm getting close to being tanked. Or do I have more? And that's when you have more in your tank. When you're doing more reps, that's a sign or doing hot like

faster, for example, running, when you're doing them higher power or faster, that's a sign that your fitness has improved, regardless of your FTP number or if it's 107 % of your FTP. So don't get blinded by numbers. They are there to guide us. But learn to understand your RPE would be my recommendation.

Paul Warloski (29:17)

What advice would you give to everyday athletes who are interested in starting or optimizing their HIIT training at the moment?

Paul Laursen (29:29)

I would say, first of all, just start if you haven't yet. And then I think probably to, you know, we've spoken about it a couple times on this podcast where we've been talking about that progression as you go from ERG mode to the high performance athlete and really, you know, ultimately to Marjaana's point in developing your

Paul Warloski (29:33)


Paul Laursen (29:56)

your feel, your rating perceived exertion. So I think those are really... Yeah, that's the key. So know that you're sort of on this journey and start somewhere and then start on erg mode, but always really start of trying to connect that mind and body to the workout itself. Use the tools like Workout Reserve to...

to help guide you in terms of knowing how deep you're going into the well. And how does that workout reserve number align with how you feel? Because it can just kind of back up some of the feelings. That's why I love it. So it's like, oh yeah, that's about how I felt. That's kind of cool. That's nice. And then you almost don't even have to use those as much. And then you can just really trust in your feel.

and any given moment, yeah, be happy with where you're sort of at on those HIIT sessions.

Paul Warloski (31:05)

What advice would you give to a new person coming to see you as a coach?

Marjaana Rakai (31:11)

I want to direct this to my female athlete and say that, yes, you need to do this. Or I hope that they will learn to love them because they can be really fun pushing yourself and then understanding like you can do hard stuff and you can run fast. Um, and just enjoy, have fun. It's not, it's, it doesn't have to be super serious.

Paul Warloski (31:37)

Yeah, I think I would add two things. One is that, you know, starting with a workout like a 30 30 is a kind of a great gateway drug because a they're, they're, they're doable. They're manageable. Um, yet they're really effective. And I would also advise people that, you know, as Paul says a lot, there's a lot of ways to skin a cat. There is no one specific HIIT workout. That is the end all and be all.

There's a lot of different ones and experiment, try them, see what works for you and see what else you can

Paul Laursen (32:16)

Yeah, and the only final thought I would add, Paul, and not to take away from any of the HIIT stuff that we've spoken about, but I kind of reflect back on my colleague Phil Maffetone's advice. And let's make sure we're ready for HIIT to begin as well, right? Back to the beginning. Let's make sure that we're a healthy athlete first, because remember that HIIT comes with added stress. And...

Paul Warloski (32:36)

Good point.

Paul Laursen (32:43)

you know, you might, if you're not ready for it, then that's all, that's all good. You're not ready for it. So just start with, you know, basic movement and aerobic development first. And then bad, when you get to that point, you are, and you know, you're, you're a healthy athlete. And then to, you know, kind of to Paul's point, no, no right or wrong way to skin it, but start, you know, start, try ramping it up a little bit and see how that feels and then, and then build from there.

Paul Warloski (33:11)

That is all for this week. Thank you for listening and join us next week for the Athletes Compass podcast. You can help us by asking your training questions in the comments, liking and sharing the podcast, giving us five star reviews because after an episode like this, clearly we deserve them. Engaging with us on our social media and for Marjaana Rakai and Dr. Paul Laursen, I'm Paul Warloski and this has been the Athletes Compass podcast.

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