With my first 70.3 just 7 weeks away I’m starting to fine tune the last couple things. I have always run with a heart rate monitor and I am well aware of what my numbers need to be when I’m running however with being new to cycling only 3 years ago this will be my longest triathlon to date and the first time I feel I will need to use a heart rate monitor on the bike. So please School me on how to determine my heart rate zones and where I need to keep it for the bike. Before anyone tells me to buy a power meter please note that’s not going to happen I’m just too damn broke. 
Well if you truly do have an understanding of your HR in running then you already know how to do exactly the same thing on the bike.
HR vs run speed.
HR vs power
.
Same thing.
With running the clock is your very cheap power meter.
With cycling at some stage you have to relate HR to power so get on a trainer with power and find out.
Once you know your numbers you only need the HR.
If you really, really, really do know HR, then just a few rides with a monitor on and it will be obvious what your numbers are.
Examine data from a few rides or a couple races and it is obvious.
Ty. I typically run that 80 to 85% of my Max and that’s a very comfortable long distance sweet spot for me at least as far as running goes.
A power meter tells you, right now, what you’re putting out. With adequate training and historical logs, you will learn how much power you can put out on average for how long, given certain environmental conditions. The reason why a power meter is more helpful as a training tool than, say, a speedometer, is that the power meter takes wind and rolling resistance out of the picture, and therefore allows you to gauge your effort more accurately.
A heart rate monitor is a complementary instrument to the PM since it tells you about your body’s response to what you’re putting out, not the output itself. Best thing to do is to wear it for whatever hard efforts you still have coming up (40 km time trial type effort or something like it), see where your HR lands and how that fits with your RPE, especially if you combine the bike with something like a 5k run after.
Bear in mind that HR is affected by lots of things such as temperature, state of restedness, adrenaline, etc. But you’ll already know that from running with a HRM.
The right answer to any of this is “you should have started training with an HRM six months ago”. But, since you did not, you gotta go with what you’ve got. At least you can possibly use the data from this race to plan your execution for the next one.
So please School me on how to determine my heart rate zones and where I need to keep it for the bike. Before anyone tells me to buy a power meter please note that’s not going to happen I’m just too damn broke.
The use of the heart rate monitor is to help keep you from doing something stupid. In this case doing something usually means not getting in enough calories, though occasionally also means blowing your quads out - though truthfully a power meter is better at keeping you from blowing up your legs.
The overall idea is, you need to find a heart rate at which you can absorb your half iron nutrition. If you don’t know that either, then say 1.75 calories per pound of body weight per hour. Over the next three weeks you need to establish what heart rate on the bike allows you to absorb that many calories.
The way you do that is use a rule of thumb to get the estimate, then TEST it in race simulation workouts. You left it a bit late, but it’s still doable.
The first rule of thumb I use is 20 bpm below your zone 5 estimate from a Friel-type test. (30 minute time trial). Another way would be 5 bpm below the best you have held in an olympic distance race.
If you have data from trainingpeaks, then look at the high est hr you have held for 60 minutes, then the highest for 90 minutes. Whatever the drop was from 60, to 90, double it and subtract from your 90-minute best.
Once you have the estimate you need to test it. Head out for a 56 mile ride on your race bike, in your aerobars just like you will do on race day. Hold your heart rate at the level you estimated and feed like you will on race day. If you can do that for 56 miles, you can be pretty confident you have a good estimate of the heart rate that will work for you on race day. If your stomach backs up on you, then that heart rate is too high.
The best thing about using your heart rate for pacing in half iron is that the link between heart rate and food absorption is pretty well preserved. If you tested in 80 degree weather but the race is in 90 degree weather - then your nutrition will still work if you use the same heart rate. You will ride slower, the heat means you can’t ride as fast at the same heart rate - but your nutrition will probably still go down.
On race day the thing to be aware of is that when you exit the swim your heart rate will be high. Give it 30 minutes to settle, if your heart rate is still higher than your target then you need to back off.
Some folks instead get to thirty minutes and say “Oh my estimate of goal heart rate for the bike is off, I will just keep riding at this higher heart rate I feel fine.” Many people have reached this moment and decided to keep that high heart rate. Many have also then blown up on the run. I am one of those many actually.
That’s how you do it. Get the heart rate at which your food will be absorbed, then use that to ensure that you get through the bike without depleting yourself too much.
I agree with your statement about needing to have started this a while ago however I thought at that point in time I was going to buy a power meter but the deal fell apart. I do most of my training anymore when it comes to running with pre but also use my heart rate monitor. I am new to Triathlon in the past 3 years but have been a lifelong Runner and I’m very in tune with my body as far as what my output needs to be for long runs and sustainability. I’m assuming that will carry over to the bike or at least I hope
I have been training with a power meter for a little over a year. I agree with everything you said. a question I have is that for whatever reason, when I’m riding into a strong wind I just feel it’s harder to hold the watts I had been holding with little wind or with the wind at my back. I’m not even looking at mph just watts. I feel like I’m going crazy because I feel like it must all be mental. Has this happened to you?
for whatever reason, when I’m riding into a strong wind I just feel it’s harder to hold the watts I had been holding with little wind or with the wind at my back.
If you’re hunching over when riding into the wind or otherwise changing your position then that could affect your power output. It’s worthwhile to practice steady state efforts over a range of cadence and speed (i.e. up and down hills and in headwind/tailwind situations), so that you’re not going to be uncomfortable when things are not “just so”. It has been adequately proven that ultimate power and aerobic endurance is usually achievable over a pretty broad cadence range, so in that respect, achieving a target power output is simply a matter of pushing on the pedals, regardless of what your brain is telling you.
I do the sport since 11 years with HR and never bought a PM so I think I know something about HR and biking.
There is not really ONE answer to the question which HR you should keep in a 70.3.
It all depends on your training situation and that also has to do with how many years you did what.
To take me as an example, the first years I could not race the bike in an olympic distance over the full 40 k to the limit. After 30 k I started to become tired and slower.
So for a 70.3 I needed to be in a more moderate HR area, lets say 80 % Hfmax.
Now, after years, I can race the bike in an olympic distance with 90 % Hfmax all the way. I do not think I can do this in a 70.3, but 85 % at least. Good professionals race a 70.3 as an olympic, so they just go for it probably at 90 % Hfmax.
Edit: The HR percentages I mentioned above are those to keep as a maximum in the race, so the avarage values will be slightly lower (because of descents and so on).