In a previous article, we looked at the role of hormones in physically active women - mainly oestrogen and progesterone - and how women in particular can benefit from training periodisation.

Another hormone of high importance to both sexes is cortisol. Cortisol is often considered the 'bad guy,' probably in part due to the fact that it's also commonly referred to as the "stress hormone."

But stress is not always bad, of course. We put our bodies under stress when we exercise, and according to Jade Teta, the higher our cortisol levels during exercise, the better. This is because shorter, but more intense workouts result in the release of adrenaline, noradrenalin, cortisol, but - crucially - the additional release human growth hormone (HGH) and testosterone. HGH is especially important in women, and results in a metabolic effect that burns fat and builds lean muscle. Prolonged workouts, however, raise cortisol but without the associated release of HGH or testosterone, which is precisely why 90 minute cardio sessions do very little to transform a person's physique.

After your workout, it's equally important to lower cortisol levels, because prolonged elevated cortisol levels work in opposition to those hormones which help to build muscle. Jade Teta suggests a relaxing walk (preferably in a natural setting), protein shake, sauna, physical affection or a nap as ways of lowering cortisol levels.

Winding down can be a challenge in today's world, but reports that recent research by British neuroscientists has found that one particular sound track can reduce anxiety of up to 65%. This track is a collaborative effort between British marketing company Marconi Union and sound therapists, and was shown to slow the listener's heart rate, reduce blood pressure (you can monitor you own blood pressure quickly, accurately and easily with this home blood pressure monitor), and lower cortisol. Check it out below: