Are you extra tired but don’t know why?
Alan Couzens put together a nice summary on the role of protein in endurance sports and describes how insufficient protein in your diet may be one of the reasons why your body is requesting more Z’s.
Couzens mentions that insufficient protein intake produces a low free amino acid pool due to an athlete’s training load and life stresses. This in turn may cause your body to break down its own lean muscle (not good) and if things continue to progress down this road, an increase of the amino acid Tryptophan occurs.
What is so special about Tryptophan?
Tryptophan is an amino acid that makes us sleepy. The belief is that Typtophan increases sleepiness due to its ability to increase brain levels of serotonin (a calming neurotransmitter when present in moderate levels) and/or melatonin (a sleep-inducing hormone secreted by the pineal gland in response to darkness or low light levels).
So instead of going for a run, you want to sleep! Or as Couzens call this phenomenon – The Protein Bonk.
Basically your body is tell you to slow down and let it catch up, which is a good thing. Being unable to train for a potentially extended period of time, is not so good, especially if this could be due to a simple protein intake adjustment.
How much protein is recommended?
Couzens recommends daily protein of 1.6-2.0 g/kg body weight for elite ultra-endurance athletes (ex: Ironman). These folks are putting in large amounts of time and miles. Intense stuff. Of course not all of us fit this uber-fit and sometimes crazy category.
Hammer Nutrition’s Guide to Success also provides the daily protein guideline of 1.4-1.7 g/kg body weight which may be a good guide for the rest of the serious long course endurance athlete.
Just to provide another viewpoint, Vegetarian Sports Nutrition by Larson-Meyer recommends daily protein of 1.2-1.4 g/kg body weight for those involved in serious endurance training.
The greater the amount and intensity of training, the more you lean towards the higher side of the recommended range.
What is serious training?
Larson-Meyer states it as intense training over eight hours per week. For those not in this category Larson-Meyer’s feels that .8 g/kg (the recommended RDA) should be a sufficient daily protein amount.
Here is an couple examples of the daily protein range for all four guidelines.
weight: 160 lbs
weight in kg: weight/2.2 = 72.72 kg
- Couzens elite ultra-endurance athlete: 116 – 145 g
- Hammer Nutrition’s serious endurance athlete: 102 – 124 g
- Larson-Meyer’s serious endurance athlete: 87 – 102 g
- recreational athlete: 58 g
weight: 125 lbs
weight in kg: weight/2.2 = 56.82 kg
- Couzens elite ultra-endurance athlete: 91 – 114 g
- Hammer Nutrition’s serious endurance athlete: 80 – 100 g
- Larson-Meyer’s serious endurance athlete: 68 – 80 g
- recreational athlete: 46 g
As these are just guides, our actual protein needs are probably unique to all of us and vary depending on the day. I highly doubt it is a static number but in reality we probably don’t have to be that precise.
One thing that seems to be universally agreed upon, long course endurance athletes need more protein than the average joe to aid in our unique muscle repair and fueling needs.
Low protein intake is just one possible reason you feel like the walking dead. Extra protein won’t fix the inappropriate training and life stresses. In reality (at least in my reality), additional fatigue is part of the long course training experience especially during the peak training segments but you shouldn’t be completely trashed.
Protein is one part of the picture, but only a part. Don’t forget to look at all aspects of your training and recovery plan.
Have you ever tracked your daily protein intake?
What have been your experiences with various protein levels?
Be active – Feel the buzz!
David – EnduranceBuzz.com
Posted on 14 May 2009