So I've been recording my heart rate when I workout. I wear an HRM more to see the calories burned than anything else, but I write down the ave. heart rate and max heart rate too just to see me improve.

My last 3 workouts were at average HR of 134, 139,144 respectively.

The max HR were at 160,170,170.

Today I started thinking "Hey, I wonder if this is a moderate intensity workout or a vigorous one or what?"

So I looked up my target heart rate. (This is stuff I used to know but had forgotten. )

• Moderate activity is 55 - 69 percent of maximum heart rate (MHR).
  
• hard exercise at 70 - 89 percent MHR
  

To calculate MHR, subtract one's age from 220. To determine the lower end of moderate intensity, multiply MHR by 55 percent or 0.55; multiply MHR by 69 percent or 0.69 to determine the higher end of the moderate intensity range. These numbers represent heartbeats per minute during moderate activity.

So I'm 34, so that puts me as 220-34 - 186 as my 100%

My moderate is 102 - 128
My hard exercise is 130 - 165

So I'm doing hard exercise by heart rate.

Emotionally though, it feels easy. I'm not bored with it nor am I unhappy with it. But when do you know when it is time to change?

Does exercise feel different to you than your heart rate would indicate? Do you change by how your heart rate is or by how you feel or what?

I'm just curious.

A.

I don't start to sweat and feel tired until I'm at about 144-145 which is somewhere in the 85% range for me... when I'm in the 120s it feels easy, and in the 130s it feels moderate.

I have a heart rate monitor which I use all the time and love. (Just got a new one actually.) Here's my experience:
First of all, that max heart rate formula you give is a very rough estimate of what's true for some people. My actual max heart rate is certainly higher than what that formula would give me. According to the formula, it would be 194 (I'm 26), but I somewhat regularly get up to 205 when I'm doing intense cardio or running until I feel like I'm dying. So, my max HR is definitely higher. Yours may be as well.
Also, an average heart rate around 140 feels very moderate for me. I need to be close to 160 before it starts feeling more like hard exercise. Even around 160-170, though I really don't feel like I'm dying or working as hard as I can. It's not until 180 that I really feel like I'm working out as hard as I can.

I seem to go the opposite way: I never get my heart rate about 120 or so (I am 33) and I am sweating pretty hard at that point. I am certainly burning lots of calories (though I do exercise for a long time), because I am eating well (~1800 calories/day) and still losing at a good rate.

I don't think sweat factors in for me. I do sweat, but I never went by that as a gauge of exertion. Fitter people are more efficient at cooling so sweat more. Anyway in the south I can stand still outside and sweat buckets. That doesn't mean I'm exercising!

A.

I've been using an HRM as part of my workouts for the past six months. It's the type that has targets for the three intensity levels (low, moderate and high) and calorie burn. I really like it but I am always going over the targets on the high, since as soon as I start any intensive exercise (running, biking inclines, fast swimming) my heart rate goes up, even though I don't feel like I'm overdoing it (most of the time, ha!). So I go by how I feel and use the HRM as a guide. For example, if I'm running and my heart rate is above the high intensity range, I'll slow it down to bring it back down. Likewise if I'm at spin class and my heart rate is down in the lowest range, I'll up my cadence or incline to bump it up.

The monitor has my ranges based on whatever the average is for my age, etc. so I'd like to have it set based on my specific ranges, but I just haven't bothered to figure out how to do that.

I've used a HRM for six months and I LOVE it. I use it for calorie purposes mainly, but also it's great to see the numbers lower the fitter you get.
I did speak to my trainer about the ranges because when I started exercising my heart rate was regularly at maximum but I didn't die lol.
He said that the zones are a VERY rough calculation an example being men and women have the same zone. He said that the don't take account of height or how fit you are, plus a number of other things. He told me that they are great for monitoring fitness improvements over time, which is what I do, but he recommends using the PRE perceived rate of exertion? A scale of 1-10 with 1 being sat on the sofa and 10 working out to the point of collapse.
I have only twice hit a 10 when I first started exercising, and I don't ever want to do that again, so I use the PRE now as well as my HRM and don't worry.
When I first started running my HR was in the 180's always. On a steady run now it's in the 160's... I LOVE seeing how my health and fitness have improved by using it.

The truth is that those numbers are general, and there are as many people they aren't right for as people they are right for, it's the center of the bell curve. You should ask your doctor about this.

I have the opposite problem, my heartrate never raises much and returns to normal asap. When sitting on the couch eg it drops under 50 whereas 70-80 is considered average.

That explains a lot!! LOL! I did not sweat hardly at all at the beginning of my journey and today I was amusing myself by letting beads of sweat tickle my arm on their way down during Spin cycle class. Arm sweat amuses me because I never used to sweat there.

I use perceived exertion as well. I've gone from a max HR of 190 to a max HR of 155. I haven't decreased my activity...quite the opposite. My heart rate is far more efficient. My resting HR has gone from 95 to 46, and my max have adjusted accordingly. So although the 120's used to feel like a walk in the park on a cool day, now the 120's really feel like I'm doing something.

I change up my exercise often, throwing in new things. I also increase intensity almost every time, or as in Spin cycle class, I give my all every time. If the resistance feels good, I bump it up. I go a little faster. I make sure I feel DONE by the end of class.

Admittedly, I ignore my HR. When I was younger, I had a resting pulse of 50 bpm or under (doc actually wanted me to get a low vitals med alert bracelet, I had chronically low BP too) my target HR was somewhere in the 130s... and there was no way I could get there. Literally, killing myself on the machine, couldn't get out of the 110s.

Now that I'm older (okay, it's not that I'm older, but I'm much fatter!) my heart rate has sped up... and it shoots up as soon as I start exercising. Even then, it's erratic and somedays I hit my max rate immediately, and others I can't even hit my target- all with the same intensity.

So, I go by PRE. It works best for me because my HR numbers never seem to tell me the truth.