I've been a "light" runner since college, typically running 2 to 4 miles about once a week. About six months ago, about a quarter mile into my run, I suddenly just had to stop. No pain, no shortness of breath, just hit a wall. I walked for a few minutes and started up again and finished my run.

This started happening so frequently that I bought a Polar H10 heart monitor, and it revealed something: a sudden increase in heart rate right before I hit the wall. From about 140 to 155. So I went to a cardiologist, got a stress test and a plaque scan. Stress test was pretty easy and revealed nothing. Plaque score was a little high 115. He put me on baby aspirin but said he couldn't explain my symptoms. (My blood pressure and resting heart rate are both excellent.)

It's been a few months since then, and the problem seems to have faded away. I ran 4 miles this afternoon with no problem. Any ideas what was going on?

I don't mean this in a bad way but it sounds psychological. Our brains are weird sometimes.

Heat related?

When people talk about a "wall" a lot of times it's due to not training enough or not fueled enough. 155 really isn't that high of a heart rate to make you have to stop.

I would guess not enough free glucose during the activity causing some Hypoglycemia and concurrent tachycardia and fatigue. Maybe slug some Gatorade prior or have a bit of protein and carb prior to running.

I would stop the aspirin.

current guidelines baby aspirin

Current guidelines for baby aspirin use vary based on the purpose:

## **Prevention of Preeclampsia**
- **Pregnant Individuals**: Low-dose aspirin (81 mg daily) is recommended for those at high risk of preeclampsia, initiated between 12 and 28 weeks of gestation, ideally before 16 weeks, and continued until delivery[1].

## **Cardiovascular Disease (CVD) Prevention**
- **Adults 40-59 Years**: Aspirin may be considered for those with a 10% or greater 10-year CVD risk, but the decision should be individualized due to small net benefits[5].
- **Adults 60 Years and Older**: Not recommended for primary prevention due to increased bleeding risks outweighing benefits[3][5].

Citations:
[1] Low-Dose Aspirin Use for the Prevention of Preeclampsia ... - ACOG https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2021/12/low-dose-aspirin-use-for-the-prevention-of-preeclampsia-and-related-morbidity-and-mortality
[2] New guidelines: Should you take daily baby aspirin to prevent heart ... https://www.uchealth.org/today/new-guidelines-should-you-take-daily-baby-aspirin-to-prevent-heart-attack-stroke/
[3] New USPSTF Recommendation on Aspirin in CVD: No For Primary ... https://www.acc.org/Latest-in-Cardiology/Articles/2022/04/27/20/41/New-USPSTF-Recommendation-on-Aspirin-in-CVD
[4] USPSTF Updates Recommendation on Aspirin to Prevent CVD - AAFP https://www.aafp.org/news/health-of-the-public/uspstf-aspirin-cvd.html
[5] Recommendation: Aspirin Use to Prevent Cardiovascular Disease https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/aspirin-to-prevent-cardiovascular-disease-preventive-medication
[6] New USPSTF guidance: Continue to take low-dose aspirin if you ... https://newsroom.heart.org/news/new-uspstf-guidance-continue-to-take-low-dose-aspirin-if-you-have-a-history-of-heart-attack-afib-stroke-or-vascular-stenting
[7] Aspirin Use to Prevent Cardiovascular Disease - AAFP https://www.aafp.org/pubs/afp/issues/2022/0900/uspstf-aspirin-cvd.html
[8] Aspirin for primary prevention of cardiovascular disease https://www.ccjm.org/content/90/5/287

You can calculate your personal risk here:
https://tools.acc.org/ascvd-risk-estimator-plus/#!/calculate/estimate/

Thanks all. I'll try fueling up a little before hand, but it's not something that's ever affected me before. Most of my runs are in the morning before eating anything. Just strange that I've never experienced like this before. It's happened 8-10 times but seems to have gone away….

I've had something similar and mine is always either caffeine related or blood sugar related. Caffeine has the biggest effect for me early morning. I cut back on it and haven't had much issue since.