razorjack

Hey, i want to ride a bit more on a road bike with my HR monitor, and do some trainings,
and i'm curious how to set HR zones and even mHR. Some time ago i read that on a road bike HR max can be 10% lower than for other sports.

My max is 204 (measured on a road bike on a trainer) and once i reached 202bpm during a run, and about 198 during mtb descent.
it's strange because on a road bike (outside), even on a 15mins climb, everything is very different than on a trainer. On a trainer i can keep >80% for more than 1h, with a sprint up to 100%,
however outside, it's hard to keep that 80%, as my legs suffer more. I can see also that my cadence is much lower (probably because of the climb and my mtb background), thus, keeping 80% for 20 mins is really hard as my legs burn. and then i can do short sprints (or hard climbs) up to 90%mHR (183bpm), but only for like 30-60s and after that i'm dying - not enough air etc..
is it the case why for road bikes you set different maxHR ?
and how to set up the zones?
(i'm 181cm, 73kg)

i use elevate plugin (for Strava) so i have few insights from my trainer sessions...
but i have a feeling that my LTHR could be different on a trainer and in real world scenario. As i wrote before, on a trainer, i was able to keep >80% for one hour,
and best 20min at 89%mHR (i didn't try to keep highest possible for 20 min, so it's possible it could be even a bit higher, and also there was few minutes sprint up to my max),
which looks impossible for me on a real bike (due to lower candence? dunno, my legs wouldn't handle it)


(yes, i know that training with power meter is very popular now, but i won't buy one)

Carbonfiberboy 

Don't worry too much about the numbers. For now, just watch them. You will be interested in watching for two things: VT1 and VT2 (1st and 2nd ventilation thresholds). This is about breathing, the first thing to get hold of. After one is warmed up, then starting from a very low pace and watching one's breathing, the first thing that happens is depth of breathing increases, and then increases some more. But after a bit, just breathing deeper isn't enough, breathing rate must also increase. This is VT1, which marks the end of pure aerobic energy use. Note your HR at VT1. Below VT1 is where you do your base training.

Above VT1, anaerobic energy gradually becomes more important. Climbing a hill, gradually increase effort and cadence. First you'll pass through VT1 and your deep breathing will continue to increase in rate. But all of a sudden, you can't maintain that anymore and you'll start to pant. This is VT2. Note your HR. Gradually back off from this point back down to deep breathing and then increase again until you start to pant. Note HR again. Your lactate threshold HR (LTHR) will be just a few beats below VT2. You can use that to set zones. Never use what you think your max is because you'll always be wrong.

LTHR should be the same indoors and out. If your legs are giving out outdoors, your gearing is too high or for some reason you just won't shift down. You want to do about 90 rpm on the flat and ~80 climbing - that's for the "average rider" if there is such a thing. Talented riders spin faster.

All that said, it takes a good bit of training to be able to sustain LTHR for an hour. Just getting into it, your lungs can handle it, but your legs don't have the endurance. As your fitness very gradually increases, your speed/power at LTHR will gradually increase along with the time you can spend there, but LTHR remains about the same, though it does vary some with freshness/tiredness. LTHR will gradually drop with age. Sounds like you won't notice that for a long time. It also does vary with fitness for some people.

Seattle Forrest

It's better to set your zones up around your LTHR than your max. Do a LT test outdoors.

The reason cycling tends to have a lower maximum than other sports is because you don't use as much of your muscle mass on a bike compared to running or skiing. It's the working muscles that demand oxygen and cause your heart to beat faster.

canklecat

Same issues here. I set up my baseline around a heart rate test on the indoor trainer. It didn't translate to real world cycling. Indoors we can sit more heavily in the saddle and not worry about using energy for balance or cushioning. Old school rollers might be a closer approximation but still not quite the same as riding outdoors. Outdoors I'm using more energy for balance, cushioning against road vibration, etc.

On the indoor trainer I can consistently max out at 171-173 bpm (I'm 62). Outdoors I'm approaching redline at 160 bpm, so I set an alarm on my bike computer at 160 to remind me that I'm 30 seconds away from gassing out. I've reached 171 bpm outdoors only once in the past year, at the top of a 1/2 mile climb. Usually I'd have gassed out before then. But it depends on road conditions (smooth asphalt vs chipseal or rutted pavement), traffic and parking that demand attention and keeping my head up, etc.

And in some cases stress may be a factor if we can't find an isolated road where we don't need to worry about traffic, animals, road hazards, etc. I know from repeated experience my heart rate jumps just getting ready to ride outdoors. For indoor sessions my heart rate will be around 70 bpm while I'm walking around getting ready for the indoor trainer session.

But for an outdoor ride my heart rate will be around 80-90 bpm just getting dressed and ready, and it'll leap to 130 bpm just coasting down the 1/4 mile street from my apartment. That's because my immediate neighbors are %&$^! lunatics who'll run over you without a thought. So I'm always very tense until I'm about a mile away. My block is all apartment complexes, very few long term residents, mostly transients who have no investment in a sense of community. They're only here because rent is cheaper and they don't plan to stay long. A mile away there's an older traditional neighborhood. Residents are invested in their homes, neighborhoods and schools, and they don't regard each other as mere road bumps to be knocked aside.

I've noticed similar trends in my heart rate and perceived effort that appear consistently along the same segments of familiar routes. It consistently corresponds with road conditions, traffic, etc. If I need to watch everywhere for traffic, I won't be able to tackle the same 5% climb with the same energy as a 5% climb on the same quality pavement on another part of the route with little or no traffic, etc. So while I could set my heart rate alarm for 165 bpm to accommodate ideal conditions, I set it to 160 bpm so I'll have a cushion of a few extra seconds in a sprint climb along a busy stretch of road.

And this assumes no other factors. I also need to account for diet and medications. If I take a Sudafed for sinus congestion or Primatene tablet for asthma (it has ephedrine), those inflate my heart rate by up to 10 bpm. But that doesn't mean I'm faster or have more energy. It's just a distortion with zero benefit for cycling. Some folks have similar variations in heart rate from caffeine, blood pressure medications, etc.

razorjack

That's why i wanted to set my zones around LTHR, i guess there is only one (indoor/outdoor? or it depends how you use your muscles too...) ?
as i said, from a trainer (1h exercise), my top 20 minutes avg HR was 181bpm, from my garmin watch (from running) LTHR is 179-180bpm, so quite consistent. (and my max 202-204 reached during run and on a trainer too)

however on climbs (outdoor) i can reach such numbers >180, only for short bursts and my legs die ... (too much lactate then?), my cadence is much lower on climbs than on a levelled trainer.
so now i'm wondering if my LTHR can be different in real world scenario and on a trainer ?

Carbonfiberboy 

I only use one number.
It does matter how you train/use your muscles. That's a major part of training.

I don't think it's useful to worry much about one's exact LTHR. Your HR is going to vary and that variation is a feature, not a bug. Go by your breathing and HR both, but don't worry too much about it. Z5 is panting. Z2 is below VT1. Breathing deeply about as fast as you care to is Z4. HRs somewhere in the middle of all that is Z3. The most useful applications of HR to riding are:

Unexpected drops in HR during a ride mean you should eat.
Unexpectedly high consistent HRs during a ride mean you're dehydrated.
Unable to get HR up at the start of a ride means you're tired.
HR is a measure of physical stress. If you want to limit stress on a long ride, put a cap on your HR.
If you want a steady physical stress on a ride or climb, keep your HR steady.

If you want precision in terms of effort, use a PM. If you want to know how your body's doing, use a HRM. The more months you spend watching your HRM, the better you'll understand it.

SlvrDragon50

Did not know this, very cool! Especially the fatigue.

Seattle Forrest

Indoor vs outdoor difference is usually chalked up to windflow and temperature.

razorjack

yeah, i know temp, and circulation could be a difference (temp was quite similar + 2 fans), but also, indoors i have much higher cadence.

I'm more into enduro and DH, so short runs between 2-5 mins (once in a year, maxiavalanche - 22 mins )
so i will focus more on strength, VO2 etc. (short intervals etc)

Carbonfiberboy 

HRM won't have anything interesting to say about these. Power meter, though I doubt it would be much use on your MTB, will work well on a trainer bike for improving short term power. On short steep hills, I use a high cadence outdoors, about what I use indoors. Power is a function of force*speed. Gotta pedal fast to develop max power. On long hills, I'm more interested in economy and long term stress, at which point a HRM becomes interesting.