How To Pace Your Marathon Like A Pro

After receiving a pacemaker, marathoner Mike Sheehy not only kept running, but raced another six marathons. He shares tips on how to improve your pace.

Mike Sheehy, the youngest in a family of four boys, has been running since Day One. And he never stopped.

Sheehy ran track in high school and college and has gone on to complete more than 100 marathons and ultraruns. But when he suddenly couldn’t keep his usual pace, he ran to see a doctor.

The diagnosis took his breath away — a heart irregularity.

“My quality of life is running, being active, being outdoors and challenging myself,” said Sheehy, who works in Abbott’s Business Technology Services.

To continue this lifestyle, Sheehy needed to get a pacemaker implanted.

So he did: Abbott’s Assurity MRI device. Four months later, he raced the Boston Marathon.

“I had run for so long on a weaker heart, now my heart was beating at full strength. I felt like I was unstoppable,” Sheehy said.

This is a pretty common feeling after a pacemaker is implanted, according to Phillip B. Adamson, M.D., Chief Medical Officer for Abbott’s Heart Failure business and a cardiologist.

“You walk in with a heart condition and you essentially walk out without the condition’s impact on your life,” Adamson said.

How Pacemakers Work

Pacemakers are medical devices that use electricity to restore the heart’s rhythm.

When the heart beats in the normal 60-100 beats per minute (bpm) range, it can meet the body’s needs, pumping blood through the heart to the lungs where it gets oxygen, moving that oxygen-rich blood through the body and then returning it to the heart to restart the process.

But if the heart beats too slowly — typically fewer than 50 bpm — the body won’t have the support to do what it needs to do. People will often experience symptoms such as not being able to climb stairs or walk without getting winded and sometimes even losing consciousness.

In a millisecond, a pacemaker can sense if there’s a slow heartbeat and sends electrical signals to the heart to correct the rhythm.

An important exception to this is endurance athletes, particularly long-distance runners, who sometimes have a resting heart rate as low as 35-40 bpm, Adamson said.

“These athletes don’t usually need pacemakers,” Adamson said. “They have trained so much in long distance exertion that their nervous system ratcheted down the beats per minute their heart needs to beat to support their bodies, and they don’t have any symptoms of this low heart rate.”

That’s where Sheehy’s case was different. He was experiencing symptoms, and this was a red flag for his doctors.

“Even though I was a little sad and confused about what was going on with my heart, getting an Abbott pacemaker has enabled me to see first-hand how we help people continue doing what they love to do,” Sheehy said.

Now, not only is Sheehy still running, but his new pace is very close to his old one.

And he’s got some pacing tips to help push you to the top of your game too.


Pacing Tips

  1. Always pace. “Pacing is essentially your game plan. Without it, there’s just disaster on the horizon,” Sheehy said.
  2. Be disciplined. “You need to train your body, mind and spirit to have that discipline to hit your pace,” Sheehy said. “While you need to run at a sustainable pace, it should still challenge you — and you should make sure to run at that pace from the get-go, because it will be hard to catch up later.”
  3. Ditch the data. To find your pace, Sheehy suggests using a heart rate monitor but ditching the smart watch. “We get caught up in all the data analytics, but sometimes you just need to go to the bare basics,” Sheehy said.
  4. Take care of you. “You need to eat well and take care of yourself so you can get faster and fitter,” Sheehy said. And that self-care includes not beating yourself up over the runs that don’t go as well as you’d like.

“Instead, always ask yourself: ‘What’s one positive I can take away from this run?’”

Keeping these tips and tricks in mind, an improved pace is achievable!

Abbott is the title sponsor of the Abbott World Marathon Majors, a series of six of the largest and most renowned marathons in the world: Tokyo Marathon, Boston Marathon, TCS London Marathon, BMW BERLIN-MARATHON, Bank of America Chicago Marathon and TCS New York City Marathon. Click here to learn more.




Rx Only

Brief Summary: Prior to using these devices, please review the User’s Manual for a complete listing of indications, contraindications, warnings, precautions, potential adverse events and directions for use.


Implantation is indicated in one or more of the following permanent conditions: syncope, presyncope, fatigue, disorientation due to arrhythmia/bradycardia or any combination of those symptoms. Rate-Modulated Pacing is indicated for patients with chronotropic incompetence, and for those who would benefit from increased stimulation rates concurrent with physical activity. Dual-Chamber Pacing is indicated for those patients exhibiting: sick sinus syndrome, chronic, symptomatic second- and third-degree AV block, recurrent Adams-Stokes syndrome, symptomatic bilateral bundle branch block when tachyarrhythmia and other causes have been ruled out. Atrial Pacing is indicated for patients with sinus node dysfunction and normal AV and intraventricular conduction systems. Ventricular Pacing is indicated for patients with significant bradycardia and normal sinus rhythm with only rare episodes of A-V block or sinus arrest, chronic atrial fibrillation, severe physical disability. AF Suppression algorithm is indicated for suppression of paroxysmal or persistent atrial fibrillation episodes in patients with one or more of the above pacing indications.


Dual-chamber pulse generators are contraindicated in patients with an implanted cardioverter-defibrillator. Rate-Adaptive Pacing may be inappropriate for patients who experience angina or other symptoms of myocardial dysfunction at higher sensor-driven rates. An appropriate Maximum Sensor Rate should be selected based on assessment of the highest stimulation rate tolerated by the patient. AF Suppression™ stimulation is not recommended in patients who cannot tolerate high atrial-rate stimulation. Dual-Chamber Pacing, though not contraindicated for patients with chronic atrial flutter, chronic atrial fibrillation, or silent atria, may provide no benefit beyond that of single-chamber pacing in such patients. Single-Chamber Ventricular Demand Pacing is relatively contraindicated in patients who have demonstrated pacemaker syndrome, have retrograde VA conduction, or suffer a drop in arterial blood pressure with the onset of ventricular pacing. Single-Chamber Atrial Pacing is relatively contraindicated in patients who have demonstrated compromise of AV conduction.


The following are potential complications associated with the use of any pacing system: arrhythmia, heart block, thrombosis, threshold elevation, valve damage, pneumothorax, myopotential sensing, vessel damage, air embolism, body rejection phenomena, cardiac tamponade or perforation, formation of fibrotic tissue/local tissue reaction, inability to interrogate or program a device because of programmer malfunction, infection, interruption of desired device function due to electrical interference, loss of desired pacing and/or sensing due to lead displacement, body reaction at electrode interface or lead malfunction (fracture or damage to insulation), loss of normal device function due to battery failure or component malfunction, device migration, pocket erosion or hematoma, pectoral muscle stimulation, phrenic nerve or diaphragmatic stimulation. The following, in addition to the above, are potential complications associated with the use of rate-modulated pacing systems: inappropriate, rapid pacing rates due to sensor failure or to the detection of signals other than patient activity, loss of activity-response due to sensor failure, palpitations with high-rate pacing.

Refer to the User’s Manual for detailed indications, contraindications, warnings, precautions and potential adverse events.