Chemical behind exercise 'lift' discovered

It has been well documented that after periods of intense cardiovascular exercise a 'high' is often experienced, but the biochemical basis of this lift has remained elusive. In October British Journal of Sports Medicine, Ellen Billet and colleagues from the Department of Sports Sciences, Nottingham Trent University, found that brain levels of a chemical called phenylethylamine, which has been linked to the regulation of physical energy, mood and attention, rise by an average of over 75% after exercise.

Szabo et al. studied 20 healthy men with an average age of 22 years. The men provided two 24-hour urine samples on consecutive days, before the first of which they were asked to refrain from exercise, while on the second they ran on a treadmill at 70% of their maximum heart rate capacity for 30 minutes.

The urine samples were analysed for phenylacetic acid, a by-product of phenylethylamine turnover,...