I came across this.
emedicinehealth.com/low_pot...
healthline.com/health/potas...
"A temporary decrease in potassium may not cause any symptoms. For example, if you sweat a lot from a hard workout, your potassium levels may normalize after eating a meal or drinking electrolytes before any damage is done.
However, severe deficiencies can be life-threatening. Signs of a potassium deficiency include:
extreme fatigue
muscle spasms, weakness, or cramping
irregular heartbeat
constipation, nausea, or vomiting
"
Getting Enough Potassium advice can be found here