“Milkshakes” are the term used for sodium bicarbonate or baking soda with some sugar, electrolytes and water given to horses by nasogastric tube before racing to improve performance. Big in trotting and TB racing and banned by many racing jurisdictions. In scientific terms, this would be referred to as a potential ergogenic aid (performance enhancement).
Why
The idea is that lactic acid and acidification of the muscles leads to fatigue. It does. The next idea is that by making the blood more alkali it reduces muscle acidification.
Milkshakes in human sport
The idea of taking sodium bicarbonate has been around in human sports for almost 100 years. A review of 775 human studies found only 35 were essentially good enough to be taken seriously.
- 48% of these studies reported performance-enhancing effects after supplementing sodium bicarbonate.
- 55% of studies with an exercise duration of ≤ 4 minutes showed positive effects.
- Only 40% of studies with an exercise duration of >4 minutes showed performance enhancing and two studies showed diverse results.
So, in human sports, it’s not clear that sodium bicarbonate is performance-enhancing.
What about milkshakes for horses?
A paper from Denham and Hulme, 2020, reviewed seven randomised controlled trials, including eight experimental (exercise) trials and 74 horses. “Results indicated that sodium bicarbonate administration in 2.5 to 5 hours before a standardised treadmill test to exhaustion or simulated race (time-trial) does not influence running performance” AND “On the basis of these findings, there is high-quality evidence to suggest that sodium bicarbonate administration does not improve running performance in trained Standardbred or Thoroughbred horses.” I’m sure this won’t stop trainers from using it, though along with creatine, gamma oryzanol, dimethyl glycine (DMG) and loads of other proven to have no effect supposed ergogenic aids
Side effects of milkshaking can include GI discomfort and loose droppings. There is also a moderate risk of upper airway haemorrhage and severe bleeding from the nose as a result of passing the nasogastric tube (tube that goes up the nose and into the stomach). There is also a risk of placing the tube in the lung instead of the stomach. If the fluid is given into the lungs instead of the stomach, pneumonia (lung infection) is almost certain and, in many cases, will be fatal.
References
Denham & Hulme (2020) A systematic review and meta-analysis on sodium bicarbonate administration and equine running performance: Is it time to stop horsing around with baking soda? Journal of Equine Veterinary Science; Volume 95, December 2020, 103281. LINK
