02/09/2026
🌿 Awareness & Building Tolerance
Over the past few weeks or so, I’ve been gradually exploring my walking tolerance again.
Earlier this year, I lost some physical tolerance after reducing my B12 supplement. Before I lost tolerance I noticed air hunger, breathlessness with exertion and a higher heart rate that wasn't settling as it normally would. After a while, despite not pushing though, I lost some physical tolerance and had to reduce some activities including my work.
I found this confusing because I knew I hadn’t missed signs of doing too much, and was still taking 500mcg of B12, so it hadn't occurred to me that B12 could be contributing. There were also hormonal factors involved and perhaps something else.
Once I returned to my usual higher dose of B12, my physical tolerance gradually improved and I was able to return to much of what I had been doing before. I didn’t bring much walking back in mainly as other things and all the heat waves were enough!
With ME/CFS & PoTS it's important to understand our current tolerance and establish some stability before exploring whether we can increase it. Tolerance isn't a fixed point — it can change with different factors. I prefer to see using baselines as part of pacing in a flexible way, rather than set times or ways to do things.
I already knew where my tolerance had roughly been for walking before the setback, so I've been gradually exploring what’s possible now.
Over the past week, I've had three walks of around 35–40 minutes. One involved considerably more time on my feet overall and was probably a little more than was ideal right now as it created post exertional symptom exacerbation, though not post exertional malaise — PESE & PEM are not the same thing.
For now, my plan is to keep the frequency and length of these walks fairly consistent for a few weeks, before gradually increasing the length of one walk.
When exploring increasing tolerance, I generally suggest keeping other things relatively stable and exploring increasing an activity without triggering PEM or PESE.
Somatic awareness is another important part of this for me. Noticing what's happening with curiosity and compassion, rather than over analysis or fear, can help us respond in a wise way.
One of my guides is my heart rate: not simply the number itself, but whether it continues to rise rather than settling. I use this as information, without constantly checking it. If I do slip into over-monitoring I compassionately acknowledge this and change my focus.
Sometimes an additional short restorative rest or regulating practice can also help support stability whilst working with building tolerance.
✨ Somatic awareness, understanding tolerance levels, strategies that support stability, and self-compassion can all support exploring what may be possible and building tolerance.