Cycling on Beta Blockers

(NOTE: An update to this post – a year later has been posted on afibcyclist.net – if you found this insightful you may wish to check that out also)

So, it’s been an interesting and educational few months, and after a bunch of sourcing articles, and personal experience – here are are a few findings on how needing to be on beta blockers (beta-adrenoceptor blocker) effects cyclists.

First up – I am NOT a doctor. I AM an engineer. I AM a fat cyclist. I have cited where I have sourced the points in this article as well as I can – so keep that in mind, the internet is very “bloke down the pub says“… however with a little common sense, asking a professional where necessary – this fills in the gaps I had, and my experiences that fill in the bits that those leave.

Why?

Now it turns out that atrial fibrillation – if you go to see a GP or Hospital is all about high-risk groups – pensioners, more so women, diabetics, big drinkers people with an underlying heart condition and so on – however, if you go to a specialist they will come out with phrases you probably didn’t expect like:

“Five times higher incidence in cyclists.”

“Biggest groups cyclists, rowers, cross-country skiers.”

“You are the third cyclist I have seen today.”

…and stuff like that. Which is first up more than a little odd – as you would expect a heart that is used to running full gas for prolonged periods of time (if not running into the red every now and then) would be like any muscle trained – big, strong, and in good health.

It transpires that big is the issue.

So in my case – road cyclist – 100 miles a week – social cyclist – background in time trialling, odd silly endurance challenge – live in a mountainous part of the UK – been put on beta blockers and chemical cardioversion medication. I find myself in the curious situation of intentionally detraining my heart, and being encouraged to “get back out on my bike”  all while somewhat deer-in-headlights – and wondering just how hard IS “but do not push too hard”.

What do they do?

They slow down your hear – I AM AN OLYMPIAN! Well actually no. Despite my FitBit occasionally announcing that I am down at 40 Beats Per Minute … it affects the whole range and use. I usually hover between 45 and 48 bpm despite my well rounded “IT engineer’s figure”.

Beta blockers, also called beta adrenergic blocking agents, block the release of the stress hormones adrenaline and noradrenaline in certain parts of the body. This results in a slowing of the heart rate and reduces the force at which blood is pumped around your body. Beta blockers can also block your kidneys from producing a hormone called angiotensin II. This results in lowering your blood pressure. – BHF.org.uk

Beta-blockers (beta-adrenoceptor blocking agents) work mainly by decreasing the activity of the heart by blocking the action of hormones like adrenaline. — NHS.uk

Beta Blockers – significantly decreasse heart rate, have no effect on stroke volue, significantly decrease cardiac output, increase vascular resistance, no effect on plasma volume — aafp.org

Common side effects include: Tiredness. You may notice this most when you first start taking beta-blockers or if your dose is increased. (Check) . Cold hands and feet. You may need to wear gloves and thick socks in cold weather. (Check… and I am usually NEVER cold). A slow heart rate and dizziness. One of the ways in which beta-blockers work is to slow down your heart rate. If it becomes too slow, you may feel dizzy. If you’re worried that your heart rate is too slow, see your doctor. (Check)Bupa.co.uk

A quick Google and you are knee-deep in untold articles in cycling and triathlon forums as you have already found describing the similar issues to what you are no doubt facing.

Okay, so what is exercising like?

It is hard. It is upsetting. Moreover, after what you have been through it is also scary. I am in no hurry to have more sharp metal in my world, wires, or spending the night in a room with lots of other dudes I don’t know with people pulling the “it’s going to be okay” face.

Beta blockers slow your heart rate, and reduce the volume it shifts as well as putting your fight/flight/aggression in the toilet – the knock on is that you feel like a Volkswagen that has gone into ‘Limp Mode’.

My experiences:

Heart rate from a ride has a max below what was once my average;

Perceived rate of exertion is WAY higher than what your Garmin is telling you;

Changes of PRE need to be gradual;

Breathlessness and perspiration at really low levels of exertion;

Longer sustained efforts are not great at all and to be avoided;

General riding at around zone 2.3 – sustained efforts pushing no higher than zone 3.4;

Starting out it takes a while and effort to get the BPM into zone 2;

Hammer down Power? Hahahaha – sure, seconds of it then panting like a dog.

Think touring not road cycling. I can, and have done 50 to 60 mile rides with 5000ft of climbing – just – SLOWLY – like a snail slowly – and panting like a dog.

Issues and Worries:

No one seems to want to tell you “what is okay?” – “how hard is okay?” – “can I hurt myself?

They will come back with – oh you should exercise – or completely – you need to do at least 150 minutes of exercise a week and two sessions of strength training.

Then they look at you again, and make with the “but not too hard” … “no big hills” … I live in a mountainous part of the country…. so that’s a big ask.

With PRE all out of whack efforts of around zone 3.2 to 3.4 are sustainable for short periods, but realistically sub 3 works for me at the moment.

This being said I am realistically dropped all the time, and the liability your mates are waiting on you is not the greatest feeling.

Downsides:

This sucks. Gets you down. A lot. BUT you are doing the thing you do – that makes you – all that kinda deep stuff. Certainly, beats being back wired up to things… or worse.

Upsides:

I read in a forum somewhere the words “Hakuna Matata!” and this pretty much sums it up.

While there is a fair amount to take in and adjust to – either the change of pace of life, reacting to the spanner in the works, or indeed the medication – knocking the adrenal response down a peg or two makes the world a LOT more sufferable. Seriously. Like… wow.

As such the fact I cannot ride as I could right now, it’s a thing, and there may have been leaky eyes about that, but its not consuming me. So yeah – silver linings and all that.

Moreover, they seem to be doing their job too. An engine that works at all is better than one that is in the shop all the time…  no brainer.

Summary & Disclaimer:

I am not a physician, doctor, medical person – I am just sharing an experience…. as I spent an age searching for articles on both this condition, medication, outcomes and effects. If this helps, in any way then I am a happy bunny. DO ask your cardiologist, general practitioner, nurse practitioner, and so on. Seriously. Serious and scary stuff – check twice – keep asking – share – help others. It is a LOT more common than you think.

(NOTE: An update to this post – a year later has been posted on afibcyclist.net – if you found this insightful you may wish to check that out also)

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