An interesting source of sodium is electrolytes! Do we really need electrolytes or sports drinks (with electrolytes) during endurance activities like hiking and running, or after weight training in a gym? Instead of electrolytes, can we drink plain water instead, thereby cutting down on our total sodium intake?

A video by Dr Greger — Are Sports Drinks Safe & Effective? (6 mins, 2018) — caught me by surprise. Early in the video, Dr Greger explains that discovery of salt-sugar solution for oral rehydration is nothing short of a miracle for treating severe diarrhoea — it continues to save millions of lives even today! But should we use a similar solution after exercise as well? Key insights shared in the video:

1. Fluid consumption during exercise should be based upon thirst
2. Electrolyte intake is generally not necessary during exercise
3. Dehydration is not generally a cause of exercise-associated muscle cramping
4. Exercise-related muscle cramping is not generally related to electrolyte loss

How many popular fitness websites agree with the four points above? Very few!

The percentages under 'False' measure the number of popular fitness websites which provide false information for that point. These percentages are 93%, 90%, 98% and 100%, respectively, for the four points above. In other words, if we rely on hydration & exercise related information from popular fitness websites, we almost always get it wrong! Did that happen to me? Yes!

In the past, during long hikes and backpacking trips, I used to carry some elecrolytes and some coconut water, and I would drink water with electrolytes, or coconut water preemptively (when I wasn't thirsty) with the goal of avoiding dehydration and muscle cramps.

… but to my surprise, Dr Greger says that "dehydration is generally not a cause of exercise-associated muscle cramping", and that "exercise related muscle cramping is generally not related to electrolyte loss", and that "electrolyte intake is generally not necessary during exercise", and that "our fluid consumption during exercise should be based on thirst"! Whoa! This approach is so different from what I used to do!