||Mountain Biking with a Pacemaker
Yes, you can mountain bike -- nicely -- with a cardiac pacemaker.
Modern pacers can help you bike by increasing your heart rate to match
your exercise level, and by suppressing abnormal cardiac rhythms. Your
limitations will be based on your underlying health problems, not by the
Typical placement of a pacemaker for a right-handed
person: just below the middle of the left clavicle, between the fat and
the pectoral muscle.
| As one
mountain biking pacemaker recipient said to me, "Don't be afraid to get
the pacemaker; it can only make things better." Because information was hard
to find, I'm sharing my experiences on this page. They may, or may not,
apply to your particular cardiac condition. There's a lot here. But my
goal is to tell you everything you need to know. I'll edit the page
periodically as I learn new stuff about living with a pacemaker.
This article will include:
- My own pacemaker story; why I got it, and how it's worked for me
- Why pacemakers are installed
- How pacemakers work
- Pacemaker program adjustments by your doctor
- How you can change the paced heart rate while riding
- Protecting the pacemaker area
||In 2016, I decided it was time for me to win a national
championship for my age category. I trained hard all winter. But 20 minutes
into the first qualifying race, I lost power and felt exhausted. I could
feel my heart pounding. The hill-climb slowed to a crawl. The symptoms
were gone by the time I got to the bottom of the mountain. Second race, same
thing. Yet a cardiac workup including stress echocardiogram and Holter monitor
By 2019, the symptoms began to hit during long climbs on regular
"fun" rides. I thought I was just out of shape, as I'd been
having other health issues at the time. But I couldn't seem to "get in
shape" no matter how hard I worked out nor how much I rested. Then by spring 2020, it
was happening on almost every ride. And it got worse, coming earlier and
with lower exertion.
That's me in 2014, at a race in St George Utah called
The Cactus Hugger. I was usually on the podium for my age category after every
race, but soon I'd not even finish.
| I knew I needed
another evaluation. But what was I supposed to tell the doctor? That I got
exhausted when climbing hills on my mountain bike? He'd say, "Yeah.
You're old." And I worried that another workup under "hospital
conditions" would again fail to find anything that could be fixed.
Hitting 11,000 feet elevation in 2018, on a ride of
26 miles and 3000 vertical. Yet by the early
2021, I couldn't even get one mile uphill on a gentle slope. I could only
ride flat trails, while watching my Garmin closely to be sure my heart
rate didn't get over 110. There's almost nothing you can ride while
keeping your effort level that low!
So I decided to investigate the symptoms under the exact conditions
that brought them on. I bought a battery-powered wrist blood pressure
monitor (to see if my blood pressure was spiking during climbs) and a
pulse oximeter (to see whether my oxygen was dropping) and a cardiac
monitor (to see if what felt like a normal but heavy heartbeat was
actually an abnormal rhythm).
This little baby cost $120 and recorded Lead 2 in
5-minute snippets. It had real-time display of EKG waveforms, and
downloaded rhythm strips to computer or cell phone.
But could I mountain bike with the oximeter on my finger and the blood
pressure monitor on my wrist? Would the EKG electrodes of the monitor stay stuck
to my chest once I began to sweat? I did a test spin on my basement
trainer to see how it would all work on the trail. And bang! There it was.
I manufactured this monitor-holder from a "Flip
Phone Wrist Band" for $8. The wire goes up the sleeve of my bike
jersey to the electrodes on my chest.
Junctional ectopic rhythm. My heartbeat was coming from a spot near the
AV node, between the atrium and ventricle. It was a slower rate than the
sinus rhythm it replaced. And the atrium was beating at the same time as
the ventricle, contracting against the closed valve and sending blood
backwards into the veins of my chest.
Here's the junctional ectopic rhythm as it appears on
the little monitor.
|Regular sinus rhythm at around 68 beats per minute as I get
on the bike. I thought my resting heart rate of 50 was a sign of health.
|Once I'd exercised around 20 minutes of moderate exertion,
any effort that put my heart rate above 120 would trigger the junctional
|The heart rate would drop significantly, and the P waves
would disappear. Tall T's and ST depression indicated cardiac stress.
|The sinus node wouldn't recover for around 40 minutes of
rest. If I tried to ride, I felt weak and exhausted. Blood pressure was
|When I'd have to force myself to pedal to get back to the
car, I'd have various arrhythmias (like A Fib) over the next 24 hours.
||Tests. In addition to the general cardiologist, I saw three
different cardiac sub-specialists. I had a cardiac stress nuclear study,
cardiac CT, coronary angiogram, multi-day Holter monitor (during which I
made myself have the arrhythmia daily), treadmill stress echocardiogram
and more. It was "relative sinus insufficiency" where my heart
didn't keep up with the exertion level, and the junctional rhythm would
take over. But I'd lose 40 to 50% of my cardiac output when the arrhythmia
We spent a year trying rhythm-control medicine. And waiting to see if
it would just go away -- for example if it was a viral infection of the
heart that could run its course. I kept getting worse.
Pacemaker scar, 10 days post surgery. Already feeling
better and working out.
|Unlike most junctional ectopic rhythms, this one behaved as
though it were the sinus node. It would slow down as I pedaled slower on
the bike, so the blood flow was always inadequate. If I forced myself to
keep riding, I'd develop other ectopic rhythms as the stress on my heart
increased. Carotid sinus massage (or a drink from a cold water bottle)
would slow the junctional beats dramatically. Yet somehow the junctional
rhythm prevented the normal sinus beats from coming back until I'd sat by
the trailside for almost an hour. Then junctional rhythm would quickly
return as I started riding again to get back to my car.
I could only ride short trails that were mostly flat, and only while
watching my Garmin carefully to keep my effort level low. Once I was
warmed up, if my heart rate
stayed above 115 for a couple of minutes, the arrhythmia would begin. It began
to come on during yard work like raking leaves. Finally, I couldn't even walk briskly around the block for 30 minutes without ending up sitting in
|So in May 2021 I got my pacemaker. I was told "only 50 to 75
percent chance it will help." But the alternative was a rocking
The results from the pacemaker were dramatic.
I was immediately able to trail run, play basketball, and
ride the mountain bike. And ride it hard. By 4 weeks post implant, I was
climbing uphill at 8000 feet with heart rate hitting 145, putting in
20-mile rides. I quit watching my diagnostic monitor, because the
pacemaker always responded immediately when I'd pedal faster, and
suppressed the arrhythmia both uphill and down.
|I also noticed right away that the daily fatigue -- what
I'd thought must be part of getting older -- was dramatically better. My
ability to recover from exercise came back. Not like I was 40 years old,
but much better than before the pacemaker. Apparently my heart rate had been inadequate
to meet my metabolic needs even when I wasn't riding the bike.
Right now, that pacemaker is my $60,000 new best friend.
made to improve performance 5 months out:
- ADL "target rate" increased from 95 to 120 for
higher heart rate during low-intensity cycling
- Activity Aceleration increased so heart rate increases more
quickly during burst efforts
- Activity Deceleration prolonged for longer recovery after a
- Exercise Response slope steeper to achieve higher heart rate
during higher effort
Upper rate left at 160 -- I'd only been reaching 140
with highest efforts running or cycling
|A pacemaker is implanted to correct the effects of heart
disease that affect the cardiac rhythm. Here are some examples:
- Bradycardia. The heart simply isn't firing fast enough to keep your
blood pressure up and meet your metabolic needs.
- AV block. The sinus node is pacing, but the electrical waves aren't
reliably getting through to fire the ventricle. The block may be absolute
with nothing getting through, relative with some beats getting through, or
periodic with problems occurring only occasionally.
- Sick sinus syndrome. The sinus node isn't reliable. Sometimes, as in
"relative sinus insufficiency" it's subtle. Everything seems OK,
but the sinus node's response to exercise isn't enough to meet the body's
- Arrhythmia suppression. A pacemaker can over-ride an abnormal rhythm by
pacing the heart faster than those abnormal heart cells can fire. Or it
can pace fast enough that conditions don't arise to make the arrhythmia
occur. Or it may be that drugs have suppressed a dangerous arrhythmia
successfully, but have slowed the heart enough that a pacemaker is
necessary to speed it up.
How Modern Pacemakers Work
A pacemaker is usually implanted just below the middle
of the clavicle, nestled in a "pouch" between the subcutaneous
fat and the pectoral muscle. Two wires are threaded into the subclavian
vein and advanced to the vena cava, then into the right side of the heart.
Typically, the end of the wire has a small coil on the end that can be
twisted to "screw into" the heart muscle. One is placed in
the right atrium, and the other in the right ventricle.
The actual pacing is done by a tiny electrical shock from the pacemaker
wire, which makes heart cells "depolarize," that is, fire. The
wave of electricity spreads, making the heart muscle contract. If
electrical activity is passing normally between atrium and ventricle
through the AV node, the pacer may only shock the atrium, letting the
electricity propagate and spread down to the ventricle in the normal
fashion. If the AV node is not functional, the pacemaker will shock the
atrium, delay while the atrium contracts, then shock the ventricle.
Modern pacemakers have internal electronics that calculate how fast to
pace your heart. So it may pace at 60 beats per minute while you're
sitting on the couch, rise to 80 as you walk around the house, then
increase to 130 as you begin running around the block.
The pacer has accelerometers that detect motion. These report to a
computer chip that decides whether the jiggle of the pacemaker was just a
bump in the road, or whether the pattern of motion means you are now
running or riding a bike. The sensitivity to motion, and the response to
motion, can be programmed into the pacemaker by the specialist. Some
cyclists report that it took a couple of programming sessions over several
months before the pacemaker was "dialed in" for cycling. (While
the pacemaker can report what's going on to your cell phone via Bluetooth,
only your doctor can program the pacer. You can't make your phone tell the
pacemaker to speed up or slow down -- both for hacker reasons and moron
Pacemaker Adjustment Sessions with your Doctor
|When your pacemaker is installed, it will be programmed
based on either "factory defaults" or on a "best
guess" of your needs. The way your pacemaker responds to your
everyday activities, and to exercise, can be changed by your cardiologist in his office.
Often this is done with help from a specially-trained medical tech
representing the pacemaker company. The programming is done by placing a data-collection and programming
probe on the skin over the pacemaker. Program changes can then be made,
based on your report of what symptoms you're having and what your exercise
goals are. For this, it's
helpful if you document the paced heart rate at various points during the
activity, noting where you were in your workout and how that corresponds
Settings on the pacemaker that can be changed may include:
- Lower Rate - how low it will let your heart rate go
- Upper Rate - maximum rate at which it will pace;
higher rates allow more exertion in younger hearts
- default rate setting is often low (130ish), so
specifically ask about this setting
- ADL Response (activities of daily living -- lower levels of motion
detected by pacemaker)
- how fast it will increase your heart rate as ADLs
become more vigorous
- "target rate" set by your
doctor, where a higher target rate means you'll start the ride with higher
and have more heart rate response at
lower levels of riding exertion
- Exercise Response
- how fast it will increase your heart rate as more-vigorous
motion is detected
- example: you run hard and heart rate only gets to 120.
Increase steepness of response slope gets higher rates for the same activity
- Activity Threshold
- how sensitive the activity sensor will be to your body
motion -- responding to subtle motions vs only vigorous activity
- Activity Acceleration
- how quickly the rate will increase when the sensor detects
increasingly vigorous activity
- Activity Deceleration
- how quickly the rate decreases when activity stops
- slower deceleration is useful for recovery, or to keep the heart rate up while you stop
riding and take a
- Optimization ON/OFF
- will the pacemaker adjust itself based on the average of
your detected activity levels?
- may result in decreasing heart rate for the same stretch of
trail at the same effort level over time
Most cyclists will benefit from a low Activity Threshold (responding to
smaller motions for riding on smooth trails), a steeper Exercise Response,
and a shorter period of waiting for Activity Acceleration. If symptoms of
under-perfusion (lightheadedness, muscle weakness) occur immediately after
high exertion, a longer period of Activity Deceleration can help. For most
cyclists (but especially for road cycling), the Activity Threshold should
be set as low as possible. A higher target rate for ADLs gives you a
higher heart rate during lower-intensity riding (or road cycling).
Perhaps your pacemaker was doing fine at first, but now 6 months later you're
fighting your way uphill at a heart rate that won't go over 120. If your
pacemaker is consistently giving you a lower heart rate than it did before
-- for an identical
activity and effort -- it's likely that Optimization is enabled on your
pacemaker. There are significant advantages to having Optimization turned
on. However: When Optimization is ON, self-alteration of the pacer's programming can
occur when you spend a lot of time bouncing down the rocks on your bike.
Or if you do activities that shake the pacemaker, like operating some
types of power equipment. The pacemaker sensors detect these bumps and the
optimization turns down the response slope
-- so it takes increasingly violent or more-frequent motion of the pacemaker to get the
same high heart rate. Many bike riders, but especially road cyclists who
also do other more "violent" sports, do better with Optimization
Note that for some pacemakers, there is no distinction between low
activity (ADL Response) and sports (Exercise Response), and the rate
response is a single relationship to the amount of activity detected by
You may need to go back to your cardiologist's office a time or two to "dial
in" the pacemaker. It helps to have a log of how your heart rate is
responding to specific reproducible activities, and when during those
activities you have symptoms or feel you need "more" from your
"Controlling" the Pacemaker -- tips and tricks
|I've found my pacemaker is extremely responsive to the
difference between puttering, walking, brisk walking, running, and hard
running. And I was pleasantly surprised at how well it detects the action of
mountain biking on a trail, even when the trail seems quite smooth. (Bumps on the trail
will be detected as "exercise" by the pacemaker, added to the body motion of riding.)
But it's not perfect. "Out of the box" the pacer doesn't respond
to mountain bike riding nearly as well as it does to running.
First, be aware that it's motion in your upper body that activates the
pacemaker's heart rate algorithms. So anything that DECREASES the rate or
intensity of upper body motion will result in a LOWER heart rate as you
exert. For example, wearing a backpack. The added mass means more inertia
-- increased resistance to being moved by a bump in the trail or by motion
of your legs -- so the chest and shoulder will move less when hit with the
same bump in the trail. And while wearing a heavy backpack you'll keep
your upper body more still, on purpose. Overall, wearing a backpack makes your pacemaker
Any addition of mass to your body or your bike means you'll move down
the trail slower when expending the same effort. And that means the bumps
hit at a lower frequency, and with less intensity. So the pacemaker
response will be slower, when compared to riding free of that mass, just
when you need the pacer to fire more quickly because you're working hard.
So seriously consider what you carry with you. Perhaps your riding partner
can be the guy with the heavy tool kit that you all use. And if you must
take it with you, get the heavy stuff as far away from the pacemaker as
possible -- down in the jersey pockets or on the bike frame instead of in
Another issue is the slope of the trail. A steeper trail means you
climb slower. So bumps in the trail come slower. You're working harder
than ever, but the motion sensors receive less stimulation. So the
pacemaker heart rate slows just when you need it to speed up.
Discuss your biking experiences with your cardiologist at your
pacemaker checkup. For example, I requested that the pacer can
be programmed to taper the rhythm over a longer period of time. I'm hoping
to keep my heart rate high, and thereby avoid an arrhythmia, when I stop
riding to set up a trailside camera or deploy the drone. And I hope to
keep the heart rate high for a longer time during recovery from a trail
run or hard climb, so I don't have to pace around for 20 minutes bouncing
on my heels (to artificially keep the heart rate high during recovery and
prevent the junctional ectopic rhythm).
If your cardiologist can't "tune" the pacemaker so it
responds appropriately to mountain biking, it's up to you. Increase the
stiffness of your suspension (set your shocks so they're
"harder" and a bit "bouncier"). Change how you ride and what you
take with you. Try
riding a lighter stiffer bike: perhaps an XC racer rather than an
all-mountain rig. Consider moving your gear and fluids out of the camelbak.
So here's your basic checklist to improve the pacemaker's detection:
1- Get rid of the backpack and go to essentials-only riding
2- Increase the stiffness of your suspension
3- If you have gel gloves, go to standard gloves
4- Consider a harder (less plush) handgrip
5- Consider riding a stiffer bike (hardtail or XC full-suspension)
And if you're climbing a trail that's dusty and smooth and you're not
seeing the heart rate that you expect, here are some things you can try. Many
of them you'd normally want to avoid. But these tricks, I've
found, make the pacemaker sense more motion and thereby increase the heart
1- Go to a lower gear and spin a higher cadence
2- Get forward and put more weight on your hands
3- Lock out your rear suspension
4- Lock out your front suspension
5- Stand periodically to pedal at a lower gear than comfortable (higher cadence)
6- Have a riding partner carry part of your weight
For some activities -- for example when riding on a super-smooth
paved bike trail with a plush full-suspension bike -- I need do special
tricks to help the pacemaker "know" that I'm exercising. It's
just too smooth. So I deliberately aim for the rocks and roots. I rock
side to side on straight smooth stretches of trail. I pedal with "bad
technique" to bounce around on the bike seat. I bounce the handlebars
a few times while holding my arms stiff. And last resort, I'll take my
right hand off the handlebar and tap the pacemaker about 30 times to drive
the heart rate up. (Note: if your pacemaker has Rate Profile Optimization,
putting this sort of kinetic input into the pacemaker's motion sensor on a
regular basis can make it re-adjust its response profile, resulting in a lower heart rate
when cycling in the future.)
|For basement trainer sessions in the winter, these tricks may be your only way
of increasing the heart rate so you can pedal hard. Unlike a road
bike, there are no bumps, so your body motion is the only thing that can
tell the pacemaker that you're working out.
You can go to an easier gear to increase your pedal cadence.
Deliberately let yourself bounce a little. When you see the response you
want, you can back off to a smaller cog for a while.
You can rock your shoulders as you pedal. This works best at higher
You can slam the
handlebars repeatedly with your arms as you pedal or while coasting.
||A pacer isn't great at responding to higher effort
levels on a road bike. That's because, if you're doing it right, your
upper body is relaxed and still. The pacer's accelerometers don't think
anything is happening.
One solution of course is to always ride your road bike on routes that
feature non-stop bumpy broken-up shoulders. The bumps make the pacer think
Dedicated roadies have learned how to give the pacemaker some
artificial motion by riding with "bad technique" as discussed
above. This tells the pacer
you're exercising, so it increases the heart rate. A heart rate display,
such as a Garmin, helps you monitor this as you ride.
For some activities, such as swimming, you may never get a
satisfactory increase in heart rate because the accelerometers simply
can't detect how hard you're working. So you may find yourself out of
breath and exhausted with a heart rate in the 70s. Some sports simply work
better than others for individuals with pacemakers.
If you need the heart rate to remain high while temporarily resting
(for example when you stop riding to talk to friends or take a break from
climbing), pace around or bounce on your heels. Or you can gently tap the
skin near one corner of the pacer with your fingertips.
Tap around twice per second. After around 10 to 20 seconds (depending on
your pacemaker programming), the paced rate will
increase as though you were running or riding bumpy trail.
Protecting the Pacemaker while biking
|With the clavicle above and the outward curve of the ribs
below, the pacer is fairly well protected from a fall onto a flat surface.
Even with mountain biking, where you may fall onto a rock or branch, blows
to the pacemaker area are rare. (You don't need to worry about
the pacemaker itself. It's covered in titanium and is virtually
indestructible! Even the wires are very difficult to break or dislodge.
The concern is the tissues over and around that pacemaker. Imagine, for
example, breaking the scar open and exposing the pacemaker.)
If you're regularly doing things that may strike the pacemaker, you can
wear body armor or buy a dedicated pacemaker protection shield that inserts
into a special undershirt. (These commercial protection systems are
surprisingly expensive. Like $200 and up. But you can put one together
yourself with a sewing machine. Sew a pocket into the undershirt over
the pacer area. Make it around 6 by 6 inches. When riding, insert a flat piece of milk-jug plastic
into that pocket to cover the pacer. If you need to shape the plastic,
warm it carefully with a propane torch and bend it to fit.)
||More likely, your issue will be your backpack straps. The
straps can push on the pacemaker incision or shove the pacemaker around.
This is especially important during the first few months as you resume
riding when the pacemaker scar isn't fully healed. But even after the
pacemaker pocket is fully healed, backpack straps may be a problem
depending on the shape of your ribs and clavicle, the prominence of your
pectoral muscles, and the amount of chest fat you carry.
Note in this photo how my backpack strap hits the healing pacer scar.
Over half of the incision is now under the strap. (The backpack is empty, but it hurt to take this photo.) And the strap
would also tend to tilt the pacemaker and shove the it toward the sternum when
the backpack strap pulls
|The simplest solution is to NOT use a backpack. My
suggestion would be that you wait at least 6 months before using even the
Once you resume use of the backpack, you may still need to add special
protection from the backpack strap (see below) depending on your body
shape, amount of fat, and weight of the filled backpack.
But see my discussion above about how a backpack decreases your
pacemaker's ability to detect that you're riding. Try eliminating the
backpack for a few rides and see how things go.
|You really don't need a backpack for shorter rides. I can
do 25 miles with three water bottles: two in jersey pockets and one on the
frame. One jersey pocket left over for keys, wallet, cell phone. All other
gear and tools are in the under-seat pack or attached to the frame.
|Use your jersey pockets. Use water bottles.
||Get an under-seat pack for tools and spare
If you don't enjoy stuffing pockets, or ride with a
pocket-less jersey, get yourself a hip pack. These are surprisingly nice
to ride with. Compared to a backpack, it puts your center of gravity lower
for fancy riding and it puts less strain on your shoulders and back.
|But there are rides where you simply need that backpack. Once you're
healed up, of course!
One simple solution to keep the strap from digging into the pacemaker
area is to make a wide cloth "donut"
that surrounds the pacemaker and takes the pressure off it. Stuff it with
This donut in the photo is a 5-inch Himalayan Singing Bowl Pillow that
I bought for $7 on EBay. If the donut feels uncomfortably hard, you may
need to unpick some stitching, remove padding, and sew it up again.
snug-fitting undershirt or tunic. Figure out where the donut should go to
surround the pacemaker.
Now you can sew a pocket to hold the donut. Or sew bits
of velcro to both shirt and donut that allow you to place it in a specific
spot. Or just safety-pin it in place.
Place your regular biking jersey over the tunic.
This works for light backpacks, but...
|For a really heavy backpack -- for example my huge video
backpack that holds cameras, drone, extra batteries, hours of water and
more -- I suggest a "stand-off" protector.
This holds the strap away from your chest, so it touches you only on
the clavicle. There is now air between the backpack strap and the pacemaker
scar. The strap can't touch the pacemaker no matter how the backpack
shifts around during rough riding.
Here's my stand-off pacemaker protector! I made this 100% from stuff that was hanging
out in my garage.
You can get straps and buckles at the hardware store, or you
can cannibalize an old broken Camelbak. You'll need one long strap (which
will be used to cover the backpack's shoulder strap) and a T-strap (which
will form a loop to
hold the backpack's chest strap and then clips into the long strap overtop of
the shoulder strap). Any strap joints -- in particular the T joint -- can
be sewn, or glued and riveted. I suggest a strap-on with buckles rather
than adding a permanent part of the Camelbak. You can transfer the
stand-off protector to any backpack with a chest strap.
To rivet a strap joint, glue it first. Then melt a hole through all the
straps with a hot nail
and place the rivet! (Propane lighter, nail, and pliers to hold the hot nail not
|A thin piece of wood (in this case, a bit of broken Venetian
blind) provides backing. I used flexible glue to attach the straps.
I like E6000 or Shoe Goo for my glue projects! You can also build up
surfaces with these glues.
Styrofoam packing can be cut up and sanded to shape. Make a curve that
fits your ribs. You may need to do some additional shaping once the
stand-off brace is fully assembled. And keep an extra unshaped piece of
foam as a backup.
Now glue the shaped styrofoam to the wood. Use a flexible
Before you glue! Test your glue on an unused bit of foam and wait a
few minutes. Many glues -- like the E6000 shown above -- will dissolve
styrofoam. If the foam starts to sink and looks pitted, try something
Automotive gasket compound worked nicely as a glue. It did
not eat into the styrofoam!
|You can now do any final shaping of the foam pad with
sandpaper. The pad
can be easily replaced if it becomes broken or dented.
This is the final result, seen as if you were looking down at it on
your chest for a left-sided pacemaker. Insert the backpack's chest strap
through the loop at right and click the chest strap. Now click the
stand-off's main strap closed over the backpack's shoulder strap.
One note: You'll probably want to make the straps a little shorter
(tighter) than shown here, particularly the loop that surrounds the chest
strap. Shorter straps prevent it from shifting during violent riding and
help keep the brace in position when you remove then replace the backpack.