It’s the end of your session, you’ve had a great workout and feeling on top of the world; and then out of nowhere you suddenly feel as though you're going to drop into a coma as all of your energy is being zapped from your body.

I’m probably guessing you’ve had some experience of this rather strange and unexplained drop in energy a few hours (or even munites) after training, something we refer too as, The Post Workout Slump (PWS).
 

Why does it occur?
 

There are many reasons why we can end up feeling tired and mentally fatiuged after training:

• Intensity of the session
• Sleep the night before
• Illness
• Blood sugar levels
• General mood
• Hormonal

These can all contribute to our energy levels during and after exercise however, these are most likely to effect our physical energy, and aren't the main reason for why we can sometimes suddenly feel whacked mentally.
 

Tryptophan is probably the main cause for the sudden onset of tiredness as it has been shown to promote fatigue after exercise (Meeusen R. 1996).

Tryptophan is a protein - the precursor for the neurotransmitter called 5-hydroxytryptamine (5-HTP) which is involved in fatigue and sleep.

When we exercise we increase the amount of tryptophan in the bloodstream (Ishikura K. Et al. 2013) increasing it’s availability to the brain within as little as 30 minutes (Blomstrand. E 2005). Once we finish our session the circulating tryptophan is then taken up by the brain and converted to 5-hydroxytryptamine (5-HTP) - minutes later and 5-HTPs effects present themselves as we’re left feeling whacked.
 

So, is there a way to combat this?
 

Well I’m glad you asked, as yes there is! Branched Chain Amino Acids (BCAA’s) have been shown to combat tryptophan’s effects and prevent PWS (Blomstrand et al. 2006). They do this by competing with tryptophan in a race to see who can reach and be taken up by the brain first; and guess who wins… the amino acids!
 

These then force tryptophan to admit defat and reside back in muscle and other tissues. (Blomstrand et al. 1995, 1997).
 

So, if you’re a person who suffers from the Post Workout Slump after exercise try adding 5-10g of BCAA’s into your water to sip on while training, I guarantee it’ll help you!
 

You’ll also find sipping on 5-10g of a carbohydrate solution during training also helps to prevent tryptophan to exert it’s fatiguing effects (Davis JM 1995).
 

BCAA’s have also been show to be particularly beneficial in raising energy in people who are overly stressed or, who suffer from chronic fatigue syndrome (CFS) (Castell LM. et al. 1999).

 

So there you have it, if we can keep a lid on the amino acid tryptophan from coverting to 5-HTP we can reduce, or even eliminate the need for a nap post exercise. It is worth noting however, that 5-HTP isn't all bad, and if you're someone who struggles to curb their carvings for carbohyrdates when dieting then 5-HTP may just become your trusted ally.

Take a look at one of our past fun facts on Tryptophan - The secret to carb cravings!