The Role of Magnesium & Muscle Recovery/ Growth

Magnesium is involved in many biochemical pathways, degradation of macronutrients, oxidative phosphorylation, DNA & protein synthesis, neuro-muscular excitability, ATP production, regulation of parathyroid hormone. Magnesium regulates phospholipids, vessel tone & blood pressure.

Magnesium is important in the role of energy production and muscle function. Magnesium is lost through sweat during intense exercise.

Protein intake with magnesium increases the uptake of magnesium.

It has been estimated that individuals who consistently take part in exercise may require 10-20% higher intake of magnesium compared to sedentary counterparts. Supplementation may be required as 1 in 2 New Zealander’s do not get enough magnesium through their diet. We burn through more magnesium when we exercise, drink alcohol or are under a lot of stress.

Exercise results in a redistribution of magnesium to the active muscle groups .

Magnesium can increase glucose availability within the blood, brain & muscle, enhance lactate clearance within the brain & exercising muscle (reduced time to fatigue). Magnesium supplementation can lower proinflammatory IL-6 levels which can lead to a reduction in exercise induced fatigue, and muscle soreness.

It is important for magnesium levels to stay high during recovery to affect cellular metabolism and protein synthesis.

• Magnesium is required for ATP production (stabilises ATP generating reactions) which fuels recovery and protein synthesis.
• Magnesium is also required for protein synthesis. Magnesium activates amino acids and aids protein biosynthesis (involved in enzymatic reactions). This leads to increased strength and protein synthesis during muscle recovery.

• Magnesium has also been shown to enhance levels of insulin like growth factor which may elevate testosterone. This may increase strength.
• Magnesium is required for muscle contraction and relaxation through stimulating calcium re-uptake. Without the restoration of calcium balance the cell may be overstimulated and may manifest as muscle spasms or cramps.
• Magnesium modulates the insulin signal transduction. Insulin in turn is critical for replenishing muscle glycogen, stimulating muscle protein growth and repair and inhibition of protein breakdown.
• Magnesium modulates cell proliferation, is important for cell adhesion and is essential for the structural function of proteins and mitochondria.

Summary of some Significant Studies

(Steward, 2019) Aim of the study was to investigate the effect of acute magnesium supplementation on exercise performance & function recovery in 8 male recreational endurance runners. Participants either received a placebo or 500mg/ day magnesium supplements for 7 days and carried out exercise. Supplementation significantly decreased circulating concentrations of IL-6, increased blood glucose 1-24hrs post exercise and reduced muscle soreness 24-72 hours after exercise. The increased post exercise blood glucose levels may lead to greater replenishment of glycogen stores post exercise.

(Pulford, 2001) Study investigated the effect of magnesium supplementation on post exercise blood pressure and muscle recovery. 6 males were given either a placebo or 300mg magnesium and carried out isokinetic knee extension. Recovery was measured by performance after initial exercise. There was a decrease in systolic blood pressure 30min post exercise and higher peak torque post maximal exercise in the magnesium group. The authors concluded that magnesium enhanced recovery potentially through in increase in blood flow to recovering muscles.

(Kass, 2013) Studied the effect of magnesium on blood pressure during recovery from aerobic and resistance exercise. 16 males received either 300mg magnesium or a placebo. The supplemented group had lower post exercise blood pressure and heart rate. Lower post exercise blood pressure aids recovery as it facilitates nutrient delivery and waste removal.

References

• One week of magnesium supplementation lowers IL-6, muscle soreness and increases 1 post exercise blood glucose in response to downhill running. Steward C.J., Zhou Y., Keane G., Cook D., Liu Y., Cullen T. (2019). European Journal of Applied Physiology.
• The effects of acute magnesium supplementation on maximal intensity short-term exercise and subsequent effect on blood pressure and isokinetic knee extension during recovery. Pulford R., & Kass L. (2001). Proceedings of the Nutrition Society.
• A Pilot Study on the Effects of Magnesium Supplementation with High and Low Habitual Dietary Magnesium Intake on Resting and Recovery from Aerobic and Resistance Exercise and Systolic Blood Pressure. Kass L.S.(2013). Journal of Sports Science and Medicine.