Exercising in Peak HR for 10 minutes? Is it safe?

[Knowledge]

So here's my dilemma. I know all about HIIT, I know about its benefits. I know about why it is superior to steady-state cardio.

My question is this. HIIT's premise is that you reach Peak HR for 30 second - 2 minutes and rest for 3 minutes and repeat 5 or 10 times. So essentially a 15-20 mintue workout.

I've been training lately, and I am nowhere near fit, but my health is improving, I'm losing weight, building muscle, getting more and more fit by the day.

Today I was able to train at around 181 BPM for 10 minutes straight (I'm 25 by the way, so this is approximately 92-95% max HR depending on which formula you use). I did not once feel tired or dizzy or anything. I did feel a slight tightness in my chest due to needing more oxygen which is expected at such a high heart rate, and for that reason I decided to call it a day, but I could have easily gone another 10 or so minutes at that intensity.

Is this dangerous for me? I know people do HIIT because it's generally easier to maintain high intensity for shorter periods of time, but is 10 minutes at Peak HR bad or dangerous in any way?

[dancefoxtrot]

Knowledge

I don't have the answer but I would go to the cardiologist and get a stress test. If you have a completely healthy heart the MD will be able to advise you on the best conditioning method. Sounds pretty awesome to be able to stay at peak 92% of max for 10 minutes and not feel tired. From what I understand going from peak down in cardio range and back again is better than stopping and starting. Endurance is cool. 

Best,

Barbara 

[Dominique]

If you want to play it safe, you should consult with a cardiologist and do an effort test (usually performed on a bicycle ergometer), just to rule out any heart disease that could put you at risk when exercising near your max HR.

[Dominique]

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@Knowledge wrote:

Today I was able to train at around 181 BPM for 10 minutes straight

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If you have access to a standard athletics track (400 meters), you could try to perform the Cooper running test (which requires you to run for 12 minutes at the maximum speed you can sustain during that time), which is a good way to gauge your cardio fitness. If you use the Digifit app, you can get an estimate of your VO2 max.

[Heybales · Accepted solution]

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@Knowledge wrote:

So here's my dilemma. I know all about HIIT, I know about its benefits. I know about why it is superior to steady-state cardio.

My question is this. HIIT's premise is that you reach Peak HR for 30 second - 2 minutes and rest for 3 minutes and repeat 5 or 10 times. So essentially a 15-20 mintue workout.

I've been training lately, and I am nowhere near fit, but my health is improving, I'm losing weight, building muscle, getting more and more fit by the day.

Today I was able to train at around 181 BPM for 10 minutes straight (I'm 25 by the way, so this is approximately 92-95% max HR depending on which formula you use). I did not once feel tired or dizzy or anything. I did feel a slight tightness in my chest due to needing more oxygen which is expected at such a high heart rate, and for that reason I decided to call it a day, but I could have easily gone another 10 or so minutes at that intensity.

Is this dangerous for me? I know people do HIIT because it's generally easier to maintain high intensity for shorter periods of time, but is 10 minutes at Peak HR bad or dangerous in any way?

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HIIT if performaned correctly is superior to steady-state for specific reasons.

It's as close to a lifting workout as you'll get for those that want to do cardio only and no lifting.

So either you had an elevated HR for some reason, not related to the intensity of the workout or the need for oxygen.

Or you have a genetically higher HRmax than the formula's estimate.

Some have Honda hearts, some have diesel. Fitness level doesn't change that. That merely helps keep your max as you age. Mine has been 194 for many years, and by normal formulas, should be around 26 yrs old. But 46, so they can be very off.

So for one, if your assement that fitness level is decent but not great is true, your HRmax is probably very high, because I doubt your lactate/anaerobic threshold is that high without specific training.

Training near LT isn't bad, but it does train the carb burning system, not the fat burning system for endurance. So depends on your goals.

If you just want to make the most of 20 min, then HIIT is it, as long as that intense muscle use isn't killing the body's attempting to repair from a good lifting session.

Using the same muscles would be as bad as lifting with the same muscles daily - not a good idea at all if you want actual body improvements from the exercise.

And when working out hard, who wouldn't want that compared to just burning more calories spinning your wheels?

But for it to be true HIIT, you have to hit (get it, ha!) max intensity in that 15-45 sec. ( 2 min is too long, can't sustain max effort for that long, think of lifting in comparison).

You can't do that on a machine.

Then you must recovery max 3 x as long as the hard interval, so 45 - 135 sec. That allows you to truly hit the next hard interval as hard as possible.

Granted, it'll feel the same, because frankly pushing with tired muscles will feel like giving it your all as pushing with fresh muscles. But the response from the body to improve is very different between those.

Like I said, HIIT when done right is as close to lifting as you'll get. Max effort for briefly, enough recovery to do it again just as hard.

Imagine what weight you'd have to pick to do squats for 2 min, compared to 45 sec. Much heavier load on muscles at 15-45 seconds, meaning better need to repair, and build stronger.

[Heybales]

Here's a max test you can do if Dr approved, or as high as you care to get, though you won't get any good stats from it.

http://www.myfitnesspal.com/blog/heybales?month=201403

[Knowledge]

Thanks for the help everyone! Definitely will get some things checked out!

[TandemWalker]

Hi @Knowledge . 

@Heybales 's post is spot on, as usual, although I am not a big fan of HIIT. 

Personally, I do like interval training, but without the high intensity factor. But yes, when done properly and if you're the type who likes to push to the max, then HIIT allegedly has its benefits.

Here's the Heart & Stroke Foundation's  recommendation: HIIT Training done right!

    TW     

[RedPlanet]

I will read the web article you posted on measuring peak HR, and talk to my doctor about testing.

I like speed walking and playing soccer, and I have played sports all my life.  My Fitbit measured heart rate often goes above my age-recommended number of 153.  I got a few numbers from my dashboard logged exercise, and HR was 158 and 179.  But the daily heartrate graph showed 142 and 162 respectively.  I wonder which numbers are more correct, but I presume the exercise rate is more correct because it samples HR more frequently. 

[DominicJ]

In a 30 minute single speed run, I'll tend to do the first 10 minutes "cardio zone" and the next 20 minutes "peak zone"

Fit bit has pretty wide zones.

I'm 30 and it puts my peak zone starting at 160bpm, which isnt that high

The highest I can find recorded is 190bpm, which is about bang on what it should be.

If you are actually holding your max HR for 10 minutes, thats a little unusual, but I couldnt give you any advice on it, neither could anyone else on here...

***

On a practical note, I dont buy the HIIT hype.

A calories is a unit of Energy, Energy cannot be created or destroyed.

Therefore, HIIT doesnt make a great deal of sense to me.

[Heybales]

One thing for holding HRmax for 10 min - it can't be your HRmax then.

No one could hold their HRmax for more than probably 15 seconds, if you think you are, it's not true max.

Actually, you do too long of a hard workout, you can't even reach HRmax with tired muscles.

That's why the HRmax tests are fast ramping, within 10-15 min you are slowly but surely getting the HR up high enough to hit max before body is too tired.

The HIIT as a fad name applied to bunch of stuff that can only be done intense is indeed silly, but for cardio sports that can be done as intervals, it's as close to weight lifting as you'll get, therefore it's the only way to add muscle for your cardio sport.

Other interval types improve volumes and lactic acid buffering/usage, steady-state improves fat burning ability, but true HIIT with diet eating in surplus can increase the muscles just like lifting, but the specific ones you need for say running.

So just like increasing the weight on the bar merely because your form improves and you get total muscle engagement, but eventually you'll top out until you stress the body to build more muscle, so also your running pace will reach a point where other max improvements have been made, and to go faster you just flat out need more muscle, and need to overstress to get it.

For those doing HIIT (or whatever the workout really is) merely for calorie burn, is because like lifting, you get better results in shorter time. But I doubt many are doing it right to actually get the lifting like fat burn during repair later. They just feel like they are doing a hard workout.

[chrisxr2]

I regularly do 20 minutes plus in peak zone if I am doing a skipping cardio workout, I am still here in one peace.

[DominicJ]

190 was the oh bleep I'm gonna die point....

[RedPlanet]

It may have been the adrenaline, but it really did not feel like that much
effort. I did feel a little winded, but not even huffing and puffing. It
felt safe because I have been doing this exercise and sports every week for
the past year, and I have built up my endurance to a comfortable level.

[RedPlanet]

I have been in the peak zone for 10+ minutes, but it's not at my maximum
heart rate. But my max HR does go higher than the formula, 220 - (your
age), and it does not seem to cause any problems to exceed that number.

[josephz2va]

I haven't done it in a while, but my recommendations on a few things are:

 - Build up the resistance: Many can't take super speed like me because we're not built up yet or have sucky lung capacity right now. Daily build up week 1 week 2 week 3 week 4 in gradual buildup. Like say I've been doing 130 to 147 BPM for a while. I'm used to it. Time for the next level of 160 BPM. Next level after that 170, 180. The machines adjusts your cardiovascular by resistance. Either by height and increasing treadmill speed to 13 MPH or using an elliptical machine which increases the pressure up to level 20 but you need super strong legs for that.

 - The maxiumum recommendation is 30 minutes cardio a day and not overstress yourself.

 - Work on lung capacity buildup: There's a few training masks out there or you can buy a cheapo lung capacity device in the health department. Elevation Training Mask for $80.

Mabis 40-950-000 Breathing Exerciser for $30. You can also look at 3 Ways to Increase Your Lung Capacity being another.

[Peggie]

my boyfriend just gave me a Fitbit Charge HR for my birthday (early 'cuz he loves me!) and I have been enjoying the upgrade from my plain-jane Zip to serious info ala heart rate and whatnot. I have been fat all my life and (thanks to Fitbit!) have recently lost 80 pounds and am at a "normal" weight. I mostly walk but also do strength training and ab work with Fitness Blender and occassionally try to improve my cardio with jogging/running short distances. My Charge HR often has my heart rate at 180bpm when I jog. JOG! Not killing myself, not even straining, just a little push more than a fast walk. My exertion level is nowhere near the exertion of trying to complete the mile and a half Navy PT twenty years ago. So I'm not sure what to think but I am tempted to agree with some other folks that the upper end results of the PurePulse technology may be a bit skewed-- a bit high. While I may be in the best shape of my life, I am not THAT fit... yet!   I'm not worried about it since you are always supposed to use these gadgets and gizmos and apps in conjunction with your "percieved amount of exersion."  In other words, if you feel like you may stroke out, slow down regardless of what your gadget says. If your gadget says you are close to death but you feel terrific.... well, use your best judgement, but you know yourself better than anyone or anything else does.

❤️ ❤️ ❤️

[DebAP]

So, are you saying the higher "peak" heart rate is OK?

I'm 66, slim, and pretty fit--a lifelong exerciser.  I go to the gym every other day, where I do 1 1/2 - 1 3/4 hrs. aerobics plus 40+ mins. weight training.  I usually walk about 2 hrs. on the other days.  (I no longer run, don't want to injure my knees.)

I really enjoy challenging exercise, and have always pushed myself within reason.  I think I know when I feel I need to slow down.

However, the Fitbit shows me at "peak" heart rate for extended periods of time, sometimes 30+ minutes.  It even shows some peak heart rate for walking with my dog-- who is frisky, and tends to trot along fast, but by no means challenges my stamina!  The walking is extremely easy for me.  (I routinely walk a lot faster minus the dog.)

I'm wondering if the Fitbit (which shows my resting heart rate as "excellant") is off.

I would really have to consciously slow down and reign myself in most days, to avoid the "peak" Fitbit numbers.

The thing is, I enjoy exercising as I currently am, and return home feeling happier for having done it and all around good.  However, I DO want to exercise in a way that helps me stay healthy, fit and trim.

[DebAP]

My question is for Heybales.

[RedPlanet]

About the high heart rate and the length of time at peak, it may be OK or it may be a real issue with your heart.  If you are a true athlete, you may have an athletic heart even at your age, and your cardiologist can run tests to determine the health of your heart under (for example) a test while hooked up to a heart monitor with ultrasound to see your heart responds when it’s under stress.  That would be the best option.  The cardiologist can tell you whether your exercise plan is OK.

I had those tests, and my heart was fine even though I often measure an hour or more at peak heart rate and my maximum rate is higher than I expected by the age formula.  I had more than 58 minutes peak during my Soccer game today, plus 38 minutes in zones 3 and 4, using a Vivoactivr HR for heart rate.  Fitbit measured 38 peak minutes but I have often seen many more minutes at peak.  But I’m good with those numbers because I got tested by my cardiologist.  So get checked by the doctors and then you will know how your heart behaves under a heavy load and maybe you can have more confidence about pushing yourself harder.