Magnesium Deficiency — “BMJ: just 6–12 weeks of strenuous physical activity can lead to magnesium deficiency”
Read the books that may save your life; see Your Doctor is NOT Responsible for Your Health—YOU Are! Recommended Reading to Open Your Mind and Ask the Right Questions, Because Your Life Depends On It, in particular, The Magnesium Miracle by Carolyn Dean, MD, ND.
This caught my eye, since I engage in year-round strenuous activity, averaging 1000 KCal/day during training season, and at least 800 KCal/day on a 365-day average.
After several weeks of strenuous physical activity, serum magnesium can increase with no change in erythrocyte magnesium levels despite a reduction in mononuclear cell magnesium levels. The authors of a study concluded that the reduction in mononuclear cell magnesium content ‘reflects a reduction in exchangeable magnesium body stores, and the onset of a magnesium deficiency state’.
This study also indicates that just 6–12 weeks of strenuous physical activity can lead to magnesium deficiency. Another study concluded: ‘Serum and urinary magnesium concentrations decrease during endurance running, consistent with the possibility of magnesium deficiency. This may be related to increased demand in skeletal muscle’.
For some years now, I have been puzzled why my peak fitness comes around mid-May and then inexplicably tends to decline and/or I have puzzling periods of weakness—which makes no sense at all(not a rest issue). At that point I typically have done six double centuries and burned about 1500 KCal/day on average since January—way more than enough to deplete magnesium. My working theory is that in spite of a 3000 to 3500 calorie per day diet (more food intake = more magnesium), I push myself into magnesium deficiency.
This year was messed up with most events canceled, but even so, I have kept my activity level fairly high. So my recent feel-better findings after magnesium supplementation are consistent with that theory and with everything I ponder about the past ten years of strenuous activity.