It's probably complete and utter rubbish, and just something that people have convinced themselves of. After the 1500m final in Rio, I don't think any of the athletes will be sitting down for a cup of tea.
There was a chinese family next door to us and their mum was always going on about "heating" and "cooling" foods. It was total junk imo. She just said that anything she didn't like the sound of was a "heating" food, regardless of what it was, and even from day to day that would change. One day lemons would be "heating", the next day they'd be "cooling". Who knew?