Ionized and Total Magnesium Levels Change during Repeated Exercise in Older Adults
Magnesium is essential for health and performance. Sub-optimal levels have been reported for older persons. In addition, physical exercise is known to temporally decrease magnesium blood concentrations.
To investigate these observations in conjunction we assessed total (tMg) and ionized magnesium (iMg) concentrations in plasma and whole blood, respectively, during 4 consecutive days of exercise in very old vital adults. Design: 68 participants (age 83.7±1.9 years) were monitored on 4 consecutive days at which they walked 30–40km (average ∼8 hours) per day at a self-determined pace. Blood samples were collected one or two days prior to the start of exercise (baseline) and every walking day immediately post-exercise. Samples were analysed for tMg and iMg levels.
Baseline tMg and iMg levels were 0.85±0.07 and 0.47±0.07 mmol/L, respectively. iMg decreased after the first walking day (−0.10±0.09 mmol/L, p<.001), increased after the second (+0.11±0.07 mmol/L, p<.001), was unchanged after the third and decreased on the final walking day, all compared to the previous day. tMg was only higher after the third walking day compared to the second walking day (p=.012). In 88% of the participants, iMg levels reached values considered to be sub-optimal at day 1, in 16% of the participants values were sub-optimal for tMg at day 2.
Prolonged moderate intensity exercise caused acute effects on iMg levels in a degree comparable to that after a bout of intensive exercise. These effects were not associated with drop-out or health problems. After the second consecutive day of exercise, levels were returned to baseline values, suggesting rapid adaptation/resilience in this population.
Key wordsOlder adults consecutive exercise days micronutrients reference values
Analysis of variance
Body mass index
Revolutions per minute
- 15.Terink, R., et al., Decrease in Ionized and Total Magnesium Blood Concentrations in Endurance Athletes Following an Exercise Bout Restores Within Hours - Potential Consequences for Monitoring and Supplementation. Int J Sport Nutr Exerc Metab, 2016: p. 1–22.Google Scholar
- 20.American College of Sports Medicine. ACSM’s guidelines for exercise testing and prescription: Lippincott Williams & Wilkins; 2013. p 5.Google Scholar
- 21.Rayana, M.C., et al., Guidelines for sampling, measuring and reporting ionized magnesium in undiluted serum, plasma or blood: International Federation of Clinical Chemistry and Laboratory Medicine (IFCC): IFCC Scientific Division, Committee on Point of Care Testing. Clin Chem Lab Med, 2005. 43(5): p. 564–9.PubMedGoogle Scholar
- 24.Vormann J, Förster R, Günther T, Ebel H, editors. Lipolysis induced magnesium uptake into fat-cells. Magnesium-bulletin; 1982: 201–2.Google Scholar