Taking full-spectrum amino acids (essential + branch chain) is something I’ve recommended to many people engaging in long-duration endurance exercise.
(In case you’re not aware, amino acids are the building blocks of protein, it’s what protein is made of. You can buy individual amino acids or a combination of amino acids from most nutrition stores).
I use them myself on long runs (above 90min) or bike rides (above 2 hours) for a specific reason: delay muscle breakdown and fatigue and minimize muscle catabolism (muscle loss), both of which are extremely common in long-distance endurance training/racing.
This is even more critical for “low carb” athletes such as myself.
HOWEVER, new scientific evidence is emerging that sheds light on an entirely new benefit to taking certain amino acids prior to exercise: a significant increase in breakdown of bodyfat.
In this new study published in the Journal of the International Society of Sports Nutrition, subject who took 3g of Phenylalanine (an essential amino acid) 30min prior to exercise saw a number of significant metabolic benefits, including a much higher rate of “fat burning”.
Blood tests showed that the subjects who took Phenylalanine saw an increase in the hormone Glucagon (which increases fat burning) as well as a drop in the respiratory exchange ratio (RER). A lower RER means that more fat and less glycogen (glucose) is being used by the muscles as fuel for exercise.
Of course, this has benefits to a wide variety of people:
- People looking to loose fat will benefit from increased fat burning before exercise
- Endurance athletes looking at becoming more efficient: higher fat utilization means you can go faster for longer, delay fatigue, spare muscle breakdown, and spare glycogen for that last push before the finish.
In fact, another study from last year showed that a combination of 3 such essential amino acids (Phenylalanine as above, but also arginine and alanine) not only increased fat breakdown in athletes, but also resulted in a significant increase in hepatic ketogenesis (production of ketone bodies by the liver). If you’re new to the subject of ketosis, ketone bodies are fat-based fuel that can be utilized by your brain, heart, and diaphragm primarily as an efficient source of fuel when glucose is not sufficiently available.
Bottom line: unless you suffer from a rare genetic disease called Phenylketonuria, you can try taking either 3g of Phenylalanine or a combination of essential amino acids (with a dosage that gives you 3g of Phe) 30 min prior to exercise for a few weeks.