HELP! 4DP for Bradycardia

PLEASE HELP, ideally someone with experience with Bradycardia

Hi everybody. I´m new to sufferfest, and relatively new to endurance training. 31 yo, male, untrained, BMI 27, VO2MAX 29 (according to the cardiac stress test on a treadmill I took a couple years ago), lost like 8kg in the last 2 years, been on maintenance 8 months now.

The thing is, I know for family history that we have really low resting HR, like proathlete resting HR of 40-45, and have a max HR of 171 aprox (same stress test couple years ago). Heard that’s called Bradycardia.

I am cleared for training, but I feel like this is messing up my 4DP. Like for example, this week I´m doing the full frontal plan, and yesterday did the Taper Efforts workout, and I wanted to die, in the first of the 3 efforts my HR reached 183, which had never happend before in the 3 years I’ve been training with a pulsometer, half marathon included.

I did the Half Monty when I started training, so i have a previous result for my 4DP and LHRT.

So… I’m a crybaby who had never suffered before??? Or is my weird HR messing up my 4DP!!!


First off, welcome to the suffer party!

I don’t know Bradycardia so I’m definitely not qualified to throw any advice your way.

I have a similar HR range so thought I’d throw in my opinion, take it with a pinch of salt.

Lots of other factors can affect your HR also, e.g. I was doing a workout last night and while power was in Zone 2 my HR was up in Z3/4 because of the heat, so keep things like heat, sleep and stress in mind when doing a workout.

I’ve done Half Monty before and found the figures that gives me were higher than what a 4DP returned for me a few weeks later. So I’d err on the side of caution and perhaps reduce those targets by a couple of percentage points to make sure it’s achievable until you do the 4DP test itself.

And dont worry, at one point or another we’re all cry babys here, but in a good way!

Best of luck,


Do you mean the 40/20s? If so I would guess (I’m no coach by any means, so take my OPINION with a grain of salt) that there is indeed something wrong like severly underrested, wrong MAP numbers, disease coming, … 6x40/20 should not get you to max HR I would assume, so you probably suffered more then you normally should have.
Or are these your first hard intervals ever? In this case I really don’t know what should feel “normal”

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@d102 So yeah, I’ve dealt with bradycardia as an athlete my whole life - enlarged heart. RHR usually in the low 40’s, though when in great shape with lots of aerobic conditioning it dropped into the mid-30’s. (Side note: Miguel Indurain had a RHR of 28bpm!).

Obv. I’m no cardiologist, with the usual caveats. But in personal experience, I can’t say that I’ve ever had issue with bradycardia impacting my top-end MHR - I think in my 20’s my MHR was up around 210ish. Once the :heart: gets up to speed, I’ve not had problems.

Now that said, what bradycardia actually is: an abnormally low heart rate - for whatever reason. The risk is that your heart can’t deliver enough oxygen for the amount of effort required, which IRL manifests as dizziness, lightheadedness, up to syncope/fainting. The biggest issue I’ve always had is that bradycardia tends to cause (or occur in parallel with) hypotension/low blood pressure. Slower HR = slower blood flow = less pressure on the blood vessels. Have you ever stood up too quickly and gotten suddenly lightheaded? That’s what that is. Ironically that can be exacerbated by improved fitness, which lowers BP, increasing the likelihood of hypotensive issues.

With cycling, and now including SUFF, the biggest trigger for me has always been a too-rapid easing off the accelerator after a hard effort, like suddenly dropping off from max HR. With bradycardia and hypotension, this causes a rapid drop off in oxygen and I get dizzy. In my younger days I learned on hard training rides that I couldn’t suddenly back off after a hard climb in the mountains, or I’d wake up laying on the side of the road a few seconds later. :grimacing:

TL;DR: yes, bradycardia can absolutely affect your body’s ability to produce sufficient oxygen during high-demand efforts, causing your cardiovascular system to “bonk” maybe sooner than your respiratory and muscular systems would need to. Training, health, and fitness will improve things, but it’s just a condition you need to understand, manage, and learn to work around.

Final caveat - it sounds like you’re making guesses based on family history and what you’re feeling on the bike. As @KevinD stated, there are MANY other issues and situations that could be impacting your workouts - including fitness, nutrition, hydration, and experience on the bike. The only way to know would be to see a cardiologist and get stress-tested, EKG, the whole shebang. If you’re concerned (and if you really are bradycardic), I strongly recommend you find a cardiologist.

And welcome to Sufferlandria. :wink:


have a max HR of 171 aprox (same stress test couple years ago)
in the first of the 3 efforts my HR reached 183

these 2 statements don’t tally, did your HR get to 171 during the stress test? Or is 171 a number your doctor has given you as a limit not to exceed. During the stress test did you feel like you were going to die like you did yesterday? It is normal for me to feel like I’m dying when at max HR, this is what suffering is, I’ll happily do it again week after week.

I’ve only done taper efforts once but my HR peaked at 178bpm (highest HR my monitor ever recorded was 185)

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Yeah, they don’t tally because teorically it shouldn’t happen jaja 171 at the time was the maximum teorical HR according to the stress test. Meaning it should be really weird for me to go over that. Now, training has probably pushed that a little higher, I’ve been hitting 175 or so on the Minnimum time max efforts workout. First time it goes over 180.

That’s the thing! In the middle of the the 40/20 I was maxed out. My doctor said that I have a really good lactate threshold for my fitness level, thats probably why I can finish half marathons, but my heart is far behind and I have a terrible VO2Max.
He recommended hit sessions to push the VO2Max up, so I’ve been doing minimum time max effort couple times a week.

Great I thought maybe I was going to get a little lower results for the full frontal. Maybe that will fix the problem. Thanks!

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Yeah, I did the whole shebang a couple years ago. Result: Terrible VO2MAX, good lactic threshold and no heart problems, so train and focus on VO2max training. Been doing MAP Workouts, but normally I’m fainting in the middle of it.