TL;DR: for some biomarkers, "sprint-interval exercise" (SIE) bursts as short as 5 min can be as effective as much longer periods of "moderate-intensity exercise" (MIE).
Specifically: MIE consisted of 90-min of continuous cycling at 90%–100% of the predetermined first lactate threshold, while SIE consisted of 6 sets of 30-s all-out cycling at a resistance of 0.075 kg·kg−1 body mass, with 4-min rests between the sets (Figure 1A).
The study's sample size was small and the period studied fairly short, but they did measure the levels of several thousand proteins.
"The One-Minute Workout: Science Shows a Way to Get Fit That's Smarter, Faster, Shorter"
EDIT: This book is maybe a bit old but covers a lot of ground on high intensity interval training vs. traditional training. I guess this study adds to the body of evidence that HIIT is effective. My take as a random person interested in this stuff is that ideally you are mixing both high intensity and longer duration workouts for their different benefits. But if you are limited in time it seems high intensity is a winner.
I found that setting a two minute timer and running up and down a stair case with high intensity once per day can resolve a whole host of seemingly unrelated issues.
I always run stairs when given an opportunity (big proponent of "incidental exercise"), so when I used to live in apartments I would deliberately rent a room in the highest available floor. It's shocking how much HIIT you can get out of running 20+ flights.
At first I thought they found something new, however it is known that exercise intensity should be of various types for the best health outcome. In my training regimen I already have a weekly session of high-intensity training, and other session at a lower intensity.
High intensity by far gives you the best gains for the time you put in, but there's only so much you can do without overtraining.
The way to really maximize your potential is to do high intensity 30 mins 3x/wk and then intersperse it with a great deal of low intensity cardio. Like 4x more if you can, per the 80/20 rule.
It works because it's starting to approach the most exercise your body can handle. (Although some athletes definitely fit in more.)
I built this HIIT timer tool www.hiitmeup.fit for exactly this reason as I try to squeeze in a compact exercise during my busy work days. I put this out on show HN a few weeks ago and hope others will find it just as useful as I do.
As an anecdote of one, I was doing moderate intensity endurance exercise for a couple years with only modest improvements in basic cardiovascular metrics that kind of flatlined over time.
As an experiment, I switched to high-intensity interval type training for a couple months, which required about half the time to do. All of my cardiovascular metrics immediately changed in a strongly positive way. When I did the old endurance training, performance was much higher than it had been before the high-intensity training.
It is the strongest positive effect I have ever seen from any exercise/gym theory that has been widely promulgated. I never expected to see my cardiovascular metrics change as quickly or as much as they did.
HIIT can have a pretty quick impact on your VO2MAX but that is going to level off. As others have said you will want a more balanced routine in the long run.
It is also possible you were over-training in your "moderate" intensity or conversely not increasing the load/distance enough. Training over years should result in good improvement even without HIIT. You will need to put a lot more time in.
I have a pretty diverse training load these days. Hiking, mountaineering, running, plus a few sports and some resistance. While I have overtrained in the past on running in particular, it was mostly due to lack of diversity. Nonetheless, none of those things puts the same load on the body as HIIT.
To be clear, I was objectively in good cardiovascular condition before adding HIIT. My resting heart rate has been in the 40s for years. The surprise was that there was so much easy margin left by adding HIIT to my regimen.
If your heart rate has been in the 40s for years your cardiovascular system is at the peak of what’s possible. It’s not “pretty good”. A resting heart rate in the 30s is the kind of thing Olympic distance runners touch on. You are either exaggerating or your assessment of what’s normal is way off. Most very fit people have resting rates in the 50s and 60s.
I never implied my cardio fitness was poor, just that some metrics are relatively better than others. My RHR (currently 47-48 per various fitness trackers) has always been pretty elite. I don’t think about it and it doesn’t change much except in response to stress.
I’m more interested in getting into the 90+ percentile range on the cardio metrics where I’m closer to the average. I don’t obsess over it, it is just interesting to see how different activities that I was going to do anyway move the needle.
Or, like me, who has never been a runner, a heart rate in the 30's can mean that you have heart block, an electrical problem with your heart where beats are gradually spaced further apart and then there is a longish delay before a reset. In a recent 2-week heart monitor test, my longest delay was 3 seconds and I had 4 of these. There are different types of heart block: mine is type 1 Mobitz/Wenckebach. Not really dangerous - I've had it all my life and known about it for ~35 years. It shows up on all of the modern automatic heart/blood pressure machines because the delays cause unusually low readings whereas a nurse checking your pulse may miss it.
My average heart rate on the test was 58, lowest was 21 (for 3 seconds), and highest was 250 (for 6 beats). A few minutes after getting in bed, my heart rate regularly is in the 40s.
That sounds exactly like what one should do for, say, couch to 10k: build a solid base in "zone 2" (low aerobic), which also serves not just as a cardio foundation but also builds the body's ability to withstand effort and impact.
Then once the base is built, to make any progress one needs stronger, more focused stimulus, so you introduce interval training at high aerobic (tempo and threshold paces) as well as anaerobic (400-800 "very hard" sustained and all-out sprints) training, combined with a few zone 2 long runs.
And then the cycle repeats: you have to let the body recover so deload, then start a new cycle.
There's a lot of noise and confusion about what exactly "zone 2" is and why. But definitely longer easier (you're not out of breath) runs build a foundation in more ways than just your cardiovascular system. It's those other components that take a longer time to build. The key is that you are not over-training (watch your sleep and joint pain as an indicator) and can recover and that you are progressively increasing your load by lessay ~10% distance a week. Easy system would be 2 shorter runs and one longer run a week.
There are plenty of online training program generators that are pretty good and will take you from zero to running 10k. I used an online program to run my first 10k somewhere circa 1990.
There a lot of more cutting edge science online (and I follow Nick as well) but if you're not a competitive athlete and are just trying to get in better shape then the answer is mostly just do it. Over some base of running you can throw in some interval training including HIIT.
I was running 10km 3x per week for a few years. When I started swapping some of those runs for HIIT, performance on the remaining 10km runs very noticeably improved in addition to the cardio metrics.
To be clear, performance-maxxing was never the objective. I am in it for the health benefits and conditioning for grueling pursuits. Nonetheless, observable effects of different kinds of training on performance are still interesting to me and helps me optimize the time I spend on it.
Are you able to point out which video explains how to find your current bottleneck? I suspect its something I would find quite useful! Unfortunately most of the videos have quite "clickbaity" titles, which makes it hard to figure out what they are about.
I don't know which video it is either, but what I've found helpful is checking aerobic decoupling. If your heart rate is drifting upward significantly over the course of an hourlong easy run despite not increasing your pace or power, then the bottleneck is probably your aerobic engine. I don't track it daily because it's a noisy metric, but looking at the overall distribution is useful.
After that it's probably determining your LTHR accurately (don't just accept what your Garmin or Apple Watch says it is). This gives a better sense of how hard to push on your hard days, and it's also useful to see what % of HRmax your threshold lands at.
Anyone starting from the couch just needs to start. I started by just pursuing a goal of "run a mile without stopping", then 2, etc.
I've messed with zone 2 a bit and read a fair amount about it. If it gets you out there moving consistently: great. The best workout plan is the one you do. But otherwise I really think it's more of an optimization strategy for people who are trying to seriously increase their miles per week, and are pairing it with higher-intensity runs and/or weight training.
I like sprinting a couple times up our hill, ca 10s each, 4-6 times. It’s full out, and when I‘m untrained (like now), I‘m quite exhausted afterwards.
But the dopamine boost I get from this is immense. It lasts 24-48h. I‘m in a general good mood for this period. Sometimes, a little more competitive than normal - that’s a downside.
Normal jogging or long walks don’t have this effect, at all.
A long race will do it just fine. AKA Runner's High.
I also do hill sprints. I try to do one [HIIT] workout a week and also some longer runs.
Hill sprints tend to be safer then sprinting on flat surfaces. Last time I did my HIIT sprinting on level ground my knee didn't really like that at all. A stationary bike (like the "assault bike") is even safer. Or you can just do burpies. People who don't run and haven't sprinted in a long time shouldn't just jump into sprinting.
I have to disagree on both points. Long races don't do this for me - that's also the point of the paper. And I have had more close calls of spraining an ankle when running uphill. The problem with hills also is that you might want to jog down after, but that's super bad for knees.
Same! I used to play Max 300 in heavy mode (on repeat) at my local arcade without hugging the bar - your feet end up moving like Donald Duck from Mathemagic Land.
30 minutes and you are gassed...
Nowadays I switched over to Pump It Up - I feel like the 5-step configuration lends itself towards larger body movements and less river dancing. :)
Does anyone have a recommendation for a dumb watch (<$100 USD) that has good programmability (flexible alarms) for a HIIT protocol? It would be nice if it had HRM but at that price point, maybe not feasible.
I don't want the fuss or expense of an Android or Apple watch. Garmin makes some nice models but they are still relatively expensive.
I would look into a used entry model Garmin. Something like a 235 (I have my old one sitting around). It has an HRM though it's not a terribly reliable one.
2nd hand Garmin or Apple Watch. These things are basically being thrown away and things like a Gen 6 AW or a Fenix 5 can be found for so little money and they work very well even today if you only care about sports tracking.
Personally something like a 2nd hand Garmin Forerunner 55 with a chest based HR monitor is for me the best budget setup. But when shopping second hand you use what you can get. I often see great deals on things like the Garmin instinct series.
2 years ago I got a Fenix 5 for 180 and it was amazing for me. Just turn off all the "smart" features.
I second this: "2nd hand Garmin Forerunner 55 and with a chest based HR monitor".
For heart rate training in general, the gold standard is an ECG-based chest strap. Avoid an optical-based monitor because you get some lag between readings or it even misses readings (this is especially evident during short intense intervals).
For a chest strap HR monitor, the main one is Polar H10, for a cheaper monitor you can get a Coospo H808S.
Saying that, I mainly use an Apple Watch Ultra 1 because it is convenient, it is good enough and I do not have to hassle with putting on a chest strap - I just have to settle with it taking a few seconds to register the correct heart rate after an intense set.
It's interesting that they characterize a 30-second cycling effort as "all-out" when any cyclist knows it's impossible to go "all-out" for that long. You can go really all-out for a few seconds before your whole metabolic process needs to switch modes. A 30-second effort has to be paced. "All-out" intervals are very effective but for me they mean 4 seconds out of every 30 seconds.
You might need to talk to a doctor if you can only go flat out for 4 seconds before having to slow down. You may put out more power during the first few seconds, but you should be able to go substantially longer than this before falling into the limitations of aerobic capacity.
I assumed this was about uphill cycling, which depending on gradient checks out to me. It's also a function of bike, cargo, and cyclist mass. Lighter cyclists find climbs easier.
You should consult your doctor if your 5-second power isn't a lot more than your 30-second power. Your instant power relies on intramuscular ATP then switches to anaerobic fast glycolysis, which is itself only good for a few tens of seconds at most. After that aerobic dominates. Untrained subjects riding 30s intervals every 5 minutes are necessarily experiencing an aerobic workout and that's why I'm surprised by this definition.
Here's a video of an amateur cyclist going all out for about a minute after spending about five minutes getting up to speed, pushing his bike to 76.11 mph.
What that rider is demonstrating is maximum lactate clearance after a long aerobic warm-up. This has nothing to do with the pathways by which high intensity intervals are thought to be beneficial.
I don't understand your objection. Anyone who is not very frail could do maximum effort for 30 seconds. It's not going to be constant power/HR/whatever but the person can still go "all-out". Consider a bear chasing you, are you going to say that you will just go all-out for 4 seconds and then pace yourself?
High-intensity exercise is obviously good, but beware of the trap of doing just high intensity exercise and doing it too frequently - the body does not handle that amount of stress particularly well, and it will be counterproductive to your health.
Low intensity exercise that holds your aerobic base is vital as well - and for a well-rounded exercise week, it should constitute the majority of your exercise time.
That is not to say that you should neglect higher intensities, it's just that you cannot do them as often due to the disproportionate amount of fatigue they generate.
Interval training also seems like a great way to burn out and make yourself dread the thought of exercise.
Other than for elite athletes tuning specifically for bursty competitions, interval training is such an unnatural torture that I do not understand the appeal. Even if the dubious popular claim that it is a short cut to optimal fitness might be partly true, I would much rather have an hour or two fun cycling or light running and exploring than 10 minutes of interval agony.
There is a constant stream of pop-science/lifestyle-advice articles advertising HIIT as a way to save time on exercise along the lines of "this smart technique, developed by a Japanese scientist will make you as fit as someone who exercises 8 hours a week with just 4 minutes per day!". Search for "Tabata" if you are curious. So a lot of those, who find regular exercise too hard, try HIIT as a replacement.
Same here in my late 30s. I was a machine. By my late 40s/early 50s it actually started to feel unhealthy, way too cardio intensive, and I switched to a more balanced cardio vs resistance mix. I think Shaun T did the same!
how come the ones who live the longest never do the HIIT treadmill hamster wheel training, but rather frequent light-to-moderate walks, bicycle rides, garden work or the like?
Can you really do HIIT on a treadmill? It doesn't sound safe to sprint on a machine.
Re your observations. Are you referring to elderly people? I'm not sure this study is about them. My mental model of this mechanism is that relatively young people can choose between e.g. long distance running and sprinting, and that the latter will yield better cardiac outcomes.
The kind of HIIT I'm doing is only 10-20s bursts, to stay within ATP-PCr energy metabolism (little lactic acid production). A short sprint followed by 2 minutes rest. That's hard to achieve with a treadmill.
62 comments
[ 0.23 ms ] story [ 57.4 ms ] threadSpecifically: MIE consisted of 90-min of continuous cycling at 90%–100% of the predetermined first lactate threshold, while SIE consisted of 6 sets of 30-s all-out cycling at a resistance of 0.075 kg·kg−1 body mass, with 4-min rests between the sets (Figure 1A).
The study's sample size was small and the period studied fairly short, but they did measure the levels of several thousand proteins.
EDIT: This book is maybe a bit old but covers a lot of ground on high intensity interval training vs. traditional training. I guess this study adds to the body of evidence that HIIT is effective. My take as a random person interested in this stuff is that ideally you are mixing both high intensity and longer duration workouts for their different benefits. But if you are limited in time it seems high intensity is a winner.
The way to really maximize your potential is to do high intensity 30 mins 3x/wk and then intersperse it with a great deal of low intensity cardio. Like 4x more if you can, per the 80/20 rule.
It works because it's starting to approach the most exercise your body can handle. (Although some athletes definitely fit in more.)
As an experiment, I switched to high-intensity interval type training for a couple months, which required about half the time to do. All of my cardiovascular metrics immediately changed in a strongly positive way. When I did the old endurance training, performance was much higher than it had been before the high-intensity training.
It is the strongest positive effect I have ever seen from any exercise/gym theory that has been widely promulgated. I never expected to see my cardiovascular metrics change as quickly or as much as they did.
It is also possible you were over-training in your "moderate" intensity or conversely not increasing the load/distance enough. Training over years should result in good improvement even without HIIT. You will need to put a lot more time in.
To be clear, I was objectively in good cardiovascular condition before adding HIIT. My resting heart rate has been in the 40s for years. The surprise was that there was so much easy margin left by adding HIIT to my regimen.
I’m more interested in getting into the 90+ percentile range on the cardio metrics where I’m closer to the average. I don’t obsess over it, it is just interesting to see how different activities that I was going to do anyway move the needle.
My average heart rate on the test was 58, lowest was 21 (for 3 seconds), and highest was 250 (for 6 beats). A few minutes after getting in bed, my heart rate regularly is in the 40s.
Then once the base is built, to make any progress one needs stronger, more focused stimulus, so you introduce interval training at high aerobic (tempo and threshold paces) as well as anaerobic (400-800 "very hard" sustained and all-out sprints) training, combined with a few zone 2 long runs.
And then the cycle repeats: you have to let the body recover so deload, then start a new cycle.
Nicklas Rossner has fantastic resources; there's a video there that explains how to find your current bottleneck: https://m.youtube.com/@NicklasRossnerPT
There are plenty of online training program generators that are pretty good and will take you from zero to running 10k. I used an online program to run my first 10k somewhere circa 1990.
There a lot of more cutting edge science online (and I follow Nick as well) but if you're not a competitive athlete and are just trying to get in better shape then the answer is mostly just do it. Over some base of running you can throw in some interval training including HIIT.
To be clear, performance-maxxing was never the objective. I am in it for the health benefits and conditioning for grueling pursuits. Nonetheless, observable effects of different kinds of training on performance are still interesting to me and helps me optimize the time I spend on it.
https://www.youtube.com/watch?v=w2ElWvS2b0c
https://www.youtube.com/watch?v=gd_E_OveCPQ
After that it's probably determining your LTHR accurately (don't just accept what your Garmin or Apple Watch says it is). This gives a better sense of how hard to push on your hard days, and it's also useful to see what % of HRmax your threshold lands at.
I've messed with zone 2 a bit and read a fair amount about it. If it gets you out there moving consistently: great. The best workout plan is the one you do. But otherwise I really think it's more of an optimization strategy for people who are trying to seriously increase their miles per week, and are pairing it with higher-intensity runs and/or weight training.
It’s always that lady who chilled all day who says laughter is how she lived so long!
But the dopamine boost I get from this is immense. It lasts 24-48h. I‘m in a general good mood for this period. Sometimes, a little more competitive than normal - that’s a downside.
Normal jogging or long walks don’t have this effect, at all.
I also do hill sprints. I try to do one [HIIT] workout a week and also some longer runs.
Hill sprints tend to be safer then sprinting on flat surfaces. Last time I did my HIIT sprinting on level ground my knee didn't really like that at all. A stationary bike (like the "assault bike") is even safer. Or you can just do burpies. People who don't run and haven't sprinted in a long time shouldn't just jump into sprinting.
30 minutes and you are gassed...
Nowadays I switched over to Pump It Up - I feel like the 5-step configuration lends itself towards larger body movements and less river dancing. :)
I don't want the fuss or expense of an Android or Apple watch. Garmin makes some nice models but they are still relatively expensive.
Personally something like a 2nd hand Garmin Forerunner 55 with a chest based HR monitor is for me the best budget setup. But when shopping second hand you use what you can get. I often see great deals on things like the Garmin instinct series.
2 years ago I got a Fenix 5 for 180 and it was amazing for me. Just turn off all the "smart" features.
For heart rate training in general, the gold standard is an ECG-based chest strap. Avoid an optical-based monitor because you get some lag between readings or it even misses readings (this is especially evident during short intense intervals).
For a chest strap HR monitor, the main one is Polar H10, for a cheaper monitor you can get a Coospo H808S.
Saying that, I mainly use an Apple Watch Ultra 1 because it is convenient, it is good enough and I do not have to hassle with putting on a chest strap - I just have to settle with it taking a few seconds to register the correct heart rate after an intense set.
https://www.youtube.com/watch?v=JM7I_uPJRYQ
Cows eat grass.
Film at 11^
^more research needed
Low intensity exercise that holds your aerobic base is vital as well - and for a well-rounded exercise week, it should constitute the majority of your exercise time.
That is not to say that you should neglect higher intensities, it's just that you cannot do them as often due to the disproportionate amount of fatigue they generate.
Other than for elite athletes tuning specifically for bursty competitions, interval training is such an unnatural torture that I do not understand the appeal. Even if the dubious popular claim that it is a short cut to optimal fitness might be partly true, I would much rather have an hour or two fun cycling or light running and exploring than 10 minutes of interval agony.
Re your observations. Are you referring to elderly people? I'm not sure this study is about them. My mental model of this mechanism is that relatively young people can choose between e.g. long distance running and sprinting, and that the latter will yield better cardiac outcomes.
https://en.wikipedia.org/wiki/Bioenergetic_systems#ATP%E2%80...
The treadmill also wasn't able to change speeds fast enough to really do the good Sprint simulations
The comments on that post were not nearly as favorable as this one for some reason.