Apologies if this has been dealt with here before but I couldn’t find anyone with the same symptoms that I have been experiencing. Before I go into detail I just want to confirm that I am “under investigation” by a doctor and currently waiting for a 72 hour ECG check and a 24 hour urine collection sample. I have been referred to a cardiologist, but in the current UK health system that means I will have an appointment around March / April of 2026 which is far from ideal but that’s really a topic for discussion somewhere ese. I am currently 60 years of age around 20% of body fat and a resting average HR of 45 BPM, and until recently (August 24) had an FTP of 282 bodyweight of 87kg.
I have an adult history of endurance activities, I was in the UK armed forces for 20+ years and played many sports, regularly ran 5+ days a week and have been a lifetime cyclist. From the age of 40 onwards I have been an Ironman triathlon participant, generally finishing in the top 20-25% of my age group depending on my training dedication, for most years until 2020 when covid obviously affected everything.
I first had these symptoms in 2019 when participating in a CXTRI in Patagonia, when on the bike leg I felt what was a double beat of my heart and my heart rate dropped immediately from 120 BPM to 80 BPM. I was immediately breathless as a result and had to stop for 2-3 minutes during which my HR rose back to 100 BPM and I regained my breath. I continued to complete the race albeit in a very poor time and had to walk a large portion of the run leg as I was struggling to raise my HR above 110 BPM. At the time my HR for a run leg would be comfortable in the 125-135 BPM.
I have had various ECG’s, echocardiograms, blood tests for multiple possible problems and all have come back clear, with many compliments on my, good cholesterol, great BMI, strong heat, good BP levels etc etc, yet the issue persists. Over that last five years it has happened with increasing frequency and in every intensity of exercise from short V02 to long endurance sessions. It happens if I am hydrated or dehydrated, it can happen if I have eaten well before and during exercise or if I have a fasted fat burning session, it happens with most exercise formats I take part in (Swim, Bike & Run) but not if I do strength work, probably as my strength work is v low intensity bodyweight only. However it doesn’t always happen and I have gone months without an incident and trained all intensities and distances / times without any concerns
I recently took 8 weeks off structured trg just doing low intensity runs, swim and leisure bike rides, just to settle in my own mind that I didn’t have some form of overtraining syndrome. I returned to trg feeling fresh and lowered my expectations of performance by first letting TR AI estimate my new FTP, which it lowered and then lowered it again myself by 10% down to 236 just to be on the safe side. I have had two weeks of trg found it all easy / moderate on the TR scale and easy RPE on my runs / swims all have been of short duration and well within my capabilities even after 8 weeks of light trg / rest. Unfortunately on a Z1 recovery ride on Friday I had the symptoms again after 16 minutes of light spinning and a HR of 100 BPM, I hadn’t even started sweating.
So the symptoms currently are:
I feel like I have a rush of blood to my head, just after / almost simultaneously my heart feels like it pounds hard once or twice, imagine a bass drum playing a double beat in your chest whilst trying to bounce out of your ribcage.
I then get breathless and have to stop / slow down dependent on the intensity of the activity and it’s form. If running then a walk will be ok, if cycling I have to stop, if swimming I have to quickly flip onto my back and scull/float while I catch my breath (not a popular move in a shared lap lane).
After a minute or two I regain my breath and I can continue the exercise at the intensity it was at pre-incident, but experience has shown that the symptoms will occur again in a few minutes time so I now warm down and stop the exercise.
The day following an incident should I attempt to train, I will have another incident (so knowing that I now do not train the next day) if I don’t train I feel breathless at any activity, walking up some stairs or similar.
Using TR or my garmin watch with a HRM I know that @ roughly the same time as “the rush of blood” and the “double beat” of my heart that I feel, my HRM will record an immediate jump in my heart rate followed by an immediate drop in my heart rate (the breathless stage) followed by a gradual return to a HR that reflects the exercise I was doing prior to the incident. For the rest of that day and for the next few days my blood pressure will be elevated by 20-30% though it then returns to a normal level and I understand it is not a concern for the medic’s who have taken it while investigating the issue.
Following an incident I generally have an easy week and then return to training and can train fine, through all power / HR zones and including longer low intensity swim, bike & swim sessions with no problem for an unspecified period when almost out of the blue an incident will occur again and it’s back to square one.
The current plan is to have the 72 hour ECG and as daft as it sounds as I write this, try to provoke an incident with my cardiovascular system that the ECG can record and hopefully indicate why this is happening.
Below are some screenshots of the Friday TR session during which I had a number of incidents the final incident is marked in these three screenshots showing the HR and the time to illustrate how quickly my HR rises and drops only to rise again during the incident.
I am posting on here simply to see if anyone has had similar symptoms, or if any medically trained members have seen similar symptoms.
Thanks in advance for the thoughts of anyone who thinks they may be able to help.
