FOCUS ON....Magnesium

Introduction:

Magnesium is an essential mineral (i.e. it MUST be provided from our diet as the body is unable to synthesise it) and is known as the “universal mineral” because it plays an important role in so many metabolic reactions (over 300) both as a mineral and a co-factor for enzymatic reactions. 

The adult human body contains about 25 grams of magnesium of which:

• Over 60% of all the magnesium is found in the skeleton
• 27% is found in muscle
• 6% to 7% is found in other cells
• Less than 1% is found outside of cells

Magnesium is known to play a key role in MANY biological processes that influence sports performance too. So, in this episode we discuss its importance in:  

• Muscle function
• Glucose metabolism
• Energy production

We then consider the effects of Magnesium status on running performance and delve into potential risk factors for suboptimal Magnesium levels including:

• Diet
• Stress
• Medication
• Age

We then move on to focus on key nutritional interventions to support optimal Magnesium status e.g. 

• Increase intake of magnesium rich foods
• Reduction of foods and beverages that may limit magnesium absorption from the digestive tract
• Magnesium supplementation

SHOW NOTES

(04:13)

Magnesium is an essential mineral involved in over 300 metabolic reactions within the body. It is also a very important mineral for a runner for many reasons including:

• Muscle function
• Glucose metabolism
• Energy production

BUT it is a mineral that is often neglected. Some studies have found that the dietary intake of magnesium is often low in athletes and yet it is thought that the magnesium demands of an athlete could be up to 10 to 20% higher than in the general population. 

(08:06)

Looking at Magnesium’s importance for the runner in more detail i.e.:

1) The muscle contraction/relaxation cycle – magnesium acts as a natural calcium blocker

2) Glucose metabolism – magnesium is influential in 3 key ways: 

• It helps regulate glucose homeostasis 
• It regulates glucose phosphorylation 
• It acts as the cofactor for several key enzymes including pyruvate hydrogenase - required for metabolic flexibility

3) Energy production – ATP (the body’s energy currency) needs to be bound to Mg to be biologically active. 

(17:39)

Compromised magnesium status could affect running performance in several ways including:

• Fatigue – linked to poor energy production
• Muscle weakness and damage – due to poor muscle function
• Reduced glucose breakdown – leading to poor energy production
• Restless leg syndrome – due to poor muscle relaxation

So, if you are experiencing any of these symptoms, it might be worth having your magnesium levels tested to determine, or hopefully rule out, a magnesium insufficiency or deficiency.

(24:10)

What are the risk factors for suboptimal magnesium levels? Well, there are many, some of which are within our control and others that are outside of our control.

Risk factors within our control include:

• Diet – low in foods containing magnesium, high in alcohol/coffee/fizzy drinks leading to poor absorption of magnesium
• Overhydration – increased excretion of Magnesium in urine
• Stress – depleted magnesium availability
• Pharmaceutical medications e.g. laxatives and diuretics – increased excretion of Magnesium

Risk factors outside of our control include:

• Age – older individuals thought to have a lower magnesium intake
• Certain...