​Magnesium Loss and the Performance Horse

​Magnesium Loss and the Performance Horse

Posted by Placide on 31st Oct 2017

At the height of Summer, horses can lose up to 10L of sweat per hour during high intensity exercise. One of the components of sweat, magnesium is an important electrolyte that must remain balanced in the body to support optimum health, wellbeing and performance.

In this article, we discuss the role of sweating and how magnesium deficiency can affect your performance horse.

While magnesium is lost via urine (100mg/L) and milk (45-90mg/L), the largest magnesium losses take place in sweat (140mg/L).

Sweating is a natural response to disperse heat and assist in reducing core body temperature. Containing sodium, chloride, potassium, calcium, phosphate, magnesium and bicarbonate, heavy sweating over long periods drains these minerals from the body.

While each electrolyte is critical, in this article, we focus specifically on magnesium, which is imperative for more than 300 biochemical reactions, including energy production, muscle contractility and nerve transmission - the cornerstones of your horse’s athletic performance.

If lost magnesium isn’t replaced or magnesium stores within the body are already depleted prior to heavy sweating, a number of health and behavioural problems can occur, including:

  • Poor tolerance to work
  • Lack of stamina
  • Muscle fatigue
  • Hypersensitivity to touch or sound
  • Anxious or nervous behaviours
  • Tight or sore back
  • Irritability when palpated either side of the spine
  • Muscle tremors
  • Bucking, spooking or other undesired behaviours
  • Inability to concentrate

For performance horses with magnesium deficiency, lactic acid rapidly builds up, leading to muscle cramping that may dispose them to tying up. At its extreme and in rare cases, magnesium deficiency can result in hypomagnesaemia, causing severe neuromuscular problems.

While magnesium is only one electrolyte lost in sweat, it’s importance cannot be underestimated and, like all other electrolytes, it must be provided by nutrition and supplementation to ensure levels remain balanced.

It is recommended that horses receive 0.1-0.12% dietary magnesium for maintenance or approximately 11-15g per day on a daily dry matter intake of 11-12kg. For the performance horse, their requirements for dietary magnesium is much higher to cover daily losses.

Placide Xtra is specifically formulated for horses regularly used in strenuous work that places heavy demands on their muscles.

Containing a high grade organic chelated magnesium, potassium and vitamin E blend, with boron, Placide Xtra supports your performance horse’s capacity for exercise, promotes endurance and eases fatigue, with positive behavioural changes seen in just one week of use.


Placide is the number one equine calming supplement in New Zealand. Containing organic, chelated magnesium, Placide works to relax muscles, reduce stress and support your horse’s health for improved performance in less than one week. Click here to find out more.

Disclaimer: This article is not intended as veterinary advice. At Placide, we encourage you to make health care decisions for your horse based on your own research and in partnership with a qualified veterinarian.