% of Max Heart Rate

campagsarge

What formula should you be using to calculate % of Max heart rate to work out your training zones?

I have read one text that states you should simply use % of MHR. So, for me that would be 0.75x185=139, which to me seems like a really low intensity for 75% of effort based on MHR.

Another formula I have seen is one using your maximum working heart rate, which is your resting HR minus your Max HR. Multiply your working HR by the % then add your resting heart rate.

So for me that would be:

185-58=127
0.75x127=95
95+58=153

153 seems more like to me.

I have read with interest the limits of HRM and I use one only as a guide but I would like to know which is the correct formula?

chill123

when i first started ridng semi seriously i was amazed how slow 75% MHR is. i was convinced it was doing me no good riding at such a low intensity for so much of the time. however when i compared my progress to a friend's who was using the "just go out and ride fast " approach to training it was remarkable how much my riding developed more.

I just use % of my max HR. Defining your MHR is the tricky part. Try to do a field test to guage your max as the age related formula can be unreliable for some people (though it is about right for me!).


As you've said do not rely solely on HR training however if used correctly it is a great tool to help you structure your training as well as helping minimise the chances of overtraining.

Take a look at this cycling heart rate training article.

Alex_Simmons/RST

chill123 wrote:

Take a look at this cycling heart rate training article.

Shame it contains several myths, like:

- Level 2: "improve your body's efficiency of using fat as its primary fuel source"
(actually training at higher intensities does a far more effective job of that since our ability to utilise fat as fuel is constrained by our oxygen transport capacity);

- Level 3: "The aim is to work as hard as you can without reaching your lactate threshold which is where the body starts using it's carbohydrate or glycogen stores as fuel instead of fat"
(our bodies use CHO & FFA at all intensities, even at rest);

- Level 4: "As discusesed elsehwer your lactate threshold is the pooint at which lactate acid removal in your muscles is outstipped by lactate removal resulting in muscle fatigue".
(Lactate doesn't cause muscle fatigue. Lactate is actually a fuel source). Not sure what they mean by "lactate acid"?

deal

im currently loosely following a training program from the spring cyclingweekly health and fitness magazine (it requires 7 hours a week but i have more free time so I have extended some of the rides and added an extra ride in). The magazine contains three programs and in each of these the heart rate zones are defined as a percentage of functional threshold, ie.

Easy, 69-83% FT
Steady, 84-94% FT
Brisk, 95-105% FT
Hard, 106%+ FT
V. Hard, Flat-out

is this a better approach then simply using % of max heart rate ? and what is the best method to determine the FT, they suggest three methods listed in order of accuracy:

1. a formula which im guessing sucks
2. 95% of average HR for a 30min hard as you can ride
3. average HR for a 1 hour hard as you can ride

Alex_Simmons/RST

deal wrote:

is this a better approach then simply using % of max heart rate ?

No better or worse than using properly determined Max HR as the anchor point.

deal wrote:

and what is the best method to determine the FT, they suggest three methods listed in order of accuracy:

1. a formula which im guessing sucks
2. 95% of average HR for a 30min hard as you can ride
3. average HR for a 1 hour hard as you can ride

I would say they are three methods with increasing accuracy, well at least to the extent of your HR response on that particular day. Perhaps your response over several such efforts might be better.

Be aware that HR will naturally drift higher during such longer efforts. If it doesn't, it's likely your power output is falling.

judokev

Hi Alex, I have read a few posts from you and others regarding heart rate and power out put

When I go out I keep a note in my diary of time taken on ride, distance, weather conditions and average heart rate.
Now if I am doing the same ride as I have done before in similar conditions in a similar time and my heart rate is about the same then I take it that my fitness is being maintained.
Is this the right way to look at this or should i be getting faster while keeping my heart rate about the same if my fitness is improving?
I cycle for some added fitness but enjoy it and mostly do short rides going quite hard as time allows, I resd above about riding at 75% having better results is this so and how do i get this figure.
I use my heart rate because i can monitor it havnt a clue on my power output?

Thanks Judokev

Alex_Simmons/RST

judokev wrote:

Hi Alex, I have read a few posts from you and others regarding heart rate and power out put

When I go out I keep a note in my diary of time taken on ride, distance, weather conditions and average heart rate.
Now if I am doing the same ride as I have done before in similar conditions in a similar time and my heart rate is about the same then I take it that my fitness is being maintained.
Is this the right way to look at this or should i be getting faster while keeping my heart rate about the same if my fitness is improving?

Sort of.

Better to use a 5+% hill of say 10-min long at least and see how fast you can climb it. If it is reasonably sheltered from the wind even better.

That will give you a much better idea of fitness changes.

There are still too many variables on a flat/rolling ride to use speed as your guage.

judokev wrote:

I cycle for some added fitness but enjoy it and mostly do short rides going quite hard as time allows, I resd above about riding at 75% having better results is this so and how do i get this figure.
I use my heart rate because i can monitor it havnt a clue on my power output?

Thanks Judokev

Riding sufficient volumes consitently above 75% MHR is where the most important physiological adaptations occur. For newer riders, it can take a while to adapt to training at these loads so working up to it in a sensible manner helps.

If you just want to be fit enough to enjoy your riding, then ride at whatever intensity pleases you.

judokev

Thanks Alex,

I am riding to help maintain my weight I do a lot of Judo which is a hard work out of a different kind, I am just looking for my first road bike at the minute so I can start doing more miles and hopefully drop some weight like the spare tyre I have that wont go :x

I am looking at riding to increase my general fitness loose weight and as something i can do when ever I get a couple of hours spare rather than watching the telly.

From what you say if I go along at 75% to 85% for longer rather than short races with myself and the stopwatch this should give better results over time yes?

Cheers judokev :P

campagsarge

I would love to train with a power meter but sadly costs prevent me from doing so . I enjoy using the HRM and the feedback it gives me. It is a useful tool but I see it no more than that. The above discussion highlights the limitations of HRM's.

Anyway, back to my original question, what is the most reliable/useful way of calculating the % of max HR?

Alex_Simmons/RST

campagsarge wrote:

Anyway, back to my original question, what is the most reliable/useful way of calculating the % of max HR?

Er, by dividing by Max HR?

campagsarge

OK, sorry here is what is confusing me and from my research there is a formula for calculating heart rate zones called the Karvonen Formula:

http://www.runnersworld.co.uk/news/article.asp?UAN=176

Or by just dividing the % by MHR.

These two separate calculations for heart rate zones give widely differing figures.

Alex_Simmons/RST

campagsarge wrote:

OK, sorry here is what is confusing me and from my research there is a formula for calculating heart rate zones called the Karvonen Formula:

http://www.runnersworld.co.uk/news/article.asp?UAN=176

Or by just dividing the % by MHR.

These two separate calculations for heart rate zones give widely differing figures.

Better to base it on what you do on a bike and not running.

Typically done through a ramp test protocol where the resistance is constantly increased until a rider can no longer sustain the effort, max HR usually occurs at the end or shortly after the end. Or climb a 5+ min hill hard and then sprint as hard as you can just before you crack. Best to have a warm up prior to such an effort.

Warning: this is a stressful test to exhaustion and is for healthy subjects only and if in any doubt, consult a qualified medical practioner.

At RST we use the following zones (all a % of HRmax):
Recovery Upto70% recovery rides up to 1hr
Zone 1 > 75% long endurance rides 1 - 6hrs
Zone 2 > 77.5% solid endurance
Zone 3 > 80% high intensity endurance
Zone 4 > 85% sub TT
Zone 5 > 87.5% TT
Zone 6 > 92.5% maximal aerobic/HC
Zone 7 N/A high intensity anaerobic (e.g., 30 secs)


However HR is a funny beast, so ....

You can group them if you like into:
Recovery < 70%
Endurance training 75% - 85%
Threshold training 85% - 92.5%
Maximal aerobic training > 92.5%
Anaerobic training - HR not applicable

Gr.uB

Campagsarge,
I asked this question on another forum recently and was given this as the reply ( the numbers in bold at the bottom I have printed off and attached to my stem as a ready reckoner / reminder ):

There are two methods of measuring your heart rate as a percentage of your maximum possible heart rate, referred to as %HRmax for short that are generally used by cyclists.

numbnuts' link is the first one, where you simply divide a particular heart rate by your maximum. Using your maxHR of 176, we can calculate these %HRmax figures for you:
0% = 0 bpm
5% = 9 bpm
10% = 18 bpm
15% = 26 bpm
20% = 35 bpm
25% = 44 bpm
30% = 53 bpm
35% = 62 bpm
40% = 70 bpm
45% = 79 bpm
50% = 88 bpm
55% = 97 bpm
60% = 106 bpm
65% = 114 bpm
70% = 123 bpm
75% = 132 bpm
80% = 141 bpm
85% = 150 bpm
90% = 158 bpm
95% = 167 bpm
100% = 176 bpm

The other one has a name, the Karvonen method. Am I allowed to use a motoring analogy on a cycling forum? The Karvonen method treats tickover as 0% rather than when the engine is off. The maths goes like this: ((heart rate)/(maxHR - RHR))+RHR. Using your RHR of 56 and maxHR of 176, we can calculate these %HRmax figures for you:
0% = 56 bpm
5% = 62 bpm
10% = 68 bpm
15% = 74 bpm
20% = 80 bpm
25% = 86 bpm
30% = 92 bpm
35% = 98 bpm
40% = 104 bpm
45% = 110 bpm
50% = 116 bpm
55% = 122 bpm
60% = 128 bpm
65% = 134 bpm
70% = 140 bpm
75% = 146 bpm
80% = 152 bpm
85% = 158 bpm
90% = 164 bpm
95% = 170 bpm
100% = 176 bpm

Your commute HR of 130 bpm would be stated as being 74% using the simple method and 62% using the Karvonen method. What's the difference and what does that mean? You mention the carb burning zone. Up to about 70%HRmax you burn some carbs and some fat. These are the base mileage rides where you can put in a lot of miles - LSD has been mentioned. The simple method says your commute at 74% is overdoing it if you want to stay below 70% so you slow down. Conversely, the Karvonen method says your commute at 62% means you can speed up and exert more energy while staying under 70%HRmax.

I learnt this from NickM in the days of the C+ forum and despite a lot of reading I cannot find which method the recommended zones are based on. Does your body start burning a higher proportion of carbs at 123bpm or 140 bpm (using your heart rates)? So, which method you choose to use becomes another Shimano/Campagnolo choice with proponents of both methods.

In 4 years of playing around with an HRM I have found the Karvonen more precise. I keep four figures in my head as a guide while I ride. If I had your HR figures, they would be:
60% = 128 bpm
70% = 140 bpm
80% = 152 bpm
90% = 164 bpm

Regarding zones, I have read a lot and forgotten a lot. I simplified it for me to:
50-60% = recovery (tired, ill, shattered)
60-70% = warm-up and LSD/base miles
70-80% = normal
80-90% = exerting (long uphills, honking)
90-100% = anaerobic (short bursts of uphill, overtaking, accelerating & sprinting only)

Alex_Simmons/RST

Gr.uB wrote:

The other one has a name, the Karvonen method. Am I allowed to use a motoring analogy on a cycling forum? The Karvonen method treats tickover as 0% rather than when the engine is off. The maths goes like this: ((heart rate)/(maxHR - RHR))+RHR. Using your RHR of 56 and maxHR of 176, we can calculate these %HRmax figures for you:

Talk about unecessary over complication.

Gr.uB wrote:

Your commute HR of 130 bpm would be stated as being 74% using the simple method and 62% using the Karvonen method. What's the difference and what does that mean? You mention the carb burning zone. Up to about 70%HRmax you burn some carbs and some fat. These are the base mileage rides where you can put in a lot of miles - LSD has been mentioned. The simple method says your commute at 74% is overdoing it if you want to stay below 70% so you slow down. Conversely, the Karvonen method says your commute at 62% means you can speed up and exert more energy while staying under 70%HRmax.

What a load of twaddle.

Up to 70% MHR is pfaffing around smelling the roses, nice for some family fun or a light recovery spin but does bugger all for fitness.

And you will continue to use FFA as a fuel source way beyond these low intensity levels (not that that matters about how you should pace yourself anyway).

Gr.uB wrote:

I learnt this from NickM in the days of the C+ forum and despite a lot of reading I cannot find which method the recommended zones are based on. Does your body start burning a higher proportion of carbs at 123bpm or 140 bpm (using your heart rates)? So, which method you choose to use becomes another Shimano/Campagnolo choice with proponents of both methods.

That is devaluing even a Campag-Shimano debate.

The relative proportion of CHO/FFA used as a fuel source is a continuum, not a switch that magically flicks over. And the intensity at which we ride is only one factor that determines that mix.

A simple change in diet is enough to completely change the rates at which FFA and CHO are used as fuel by the body at different intensities. As is one's level of fitness and oxygen tranport carrying capacity.

If riding long, just make sure you are fuelled properly (before, during and after the ride).

Gr.uB wrote:

In 4 years of playing around with an HRM I have found the Karvonen more precise.

Than what? And on what basis are you determining the precision of these zones?

"More precise" and "Heart Rate" in the same sentence makes no sense.

campagsarge

Thanks guys. I think I will go with the % of HR calculation. The bottom line (for me at least) is that the intensity that I work at is going to be guesswork until I have a proper ramp test in a lab.

Alex, the zones you mention are they similar to the ones that Peter Keen developed?

Alex_Simmons/RST

campagsarge wrote:

Thanks guys. I think I will go with the % of HR calculation. The bottom line (for me at least) is that the intensity that I work at is going to be guesswork until I have a proper ramp test in a lab.

Alex, the zones you mention are they similar to the ones that Peter Keen developed?

No. Well not the Keen zones I'm aware of. Not that it matters that much.

They work out to be pretty much the same at higher intensities and a bit different at lower intensities but there is so much "slop" in HR Zones anyway that it doesn't matter that much.

campagsarge

Thanks for you info - I am now beginning to understand the limitations of training through HR alone.

I took a look at a previous post of yours re: a graph showing a rider's wattage v HR. Illustrates the 'slop' in HR perfectly.

SteveR_100Milers

FWIW one of the key things in a HRM is customizeable zones, as using the usual 50-60, 60-70 etc is too narrow. As Alex says up to 75% ish (and you can learn this from experience and record in your mental PE *files*) is just twiddling. Anything over aprox 85% is pain and into chaingang / TT teritory which agan from experience you will learn is where you get fitness / speed gains. The most useful bit of HR advice (thanks again Aex) was the sweet spot and also the blocks of 10 minutes at TT or just under TT pace. I only ever use the HRM for riding on the turbo, as my PE scale is completely out of calibration coamperd to the road (i.e. feels much much harder, even though its isn't). So I only ever use 3 zones:

75% - 100% (as a guide to how much time I spend in aerobic development, i.e. above 75%)
80% - 92% (for "sweet spot")
88% - 100% (using the HR trace to give an aproximation to how many periods of 10 minute blocks at TT effort in any given ride).

The most useful feature for me must be the HR graph post ride, so that I can get a feel for the relative PE scales of training on the road v turbo v adrenaline rushed track sesion etc and therefore establish if a particular effort / ride is sufficiently hard. This is much more important when you have limited time, and most if not all training is done alone as mine is