What Your Spit Says About Your Training
What’s the newest way to gauge exercise intensity and fatigue? Spit in a tube.
In practice, we still use heart rate and ratings of perceived exertion (RPE) as means to measure exercise intensity and fatigue (except for maybe Dan John, who likes to tap a key on his keyboard as fast as possible for a minute every day and monitor the number of taps to test his level of fatigue). Problem is, these methods are highly subjective and not always reliable.
Research over the last several years has suggested hormone levels in saliva may be more accurate markers of intensity and better indicative of individual levels of fatigue. Until now, however, we had no way of applying the findings.
Just this month and for the first time ever, a licensed salivary test that can determine fatigue level has become available. It’s called the Fatigue Biomarker Salivary Test and it works by measuring levels of peptides in your spit. These peptides decrease up to 10,000-fold with high levels of fatigue.
The test was developed by Hyperion Biotechnology following a series of studies done on the U.S. Military that aimed to find a way to send soldiers out to fight with less fatigue. The bad news is, it isn’t that practical yet…As of now, you have to mail your tube of spit back to the lab for analysis and await the results – so it doesn’t seem like we can yet use our spit to adjust intensity on the spot during an actual training session.
It does have some pretty exciting implications for the future, though. We typically make the recommendation to wait about 72 hours after a session to reapply the stimulus for optimal results, but this is really just an estimate based on time rather than individual physiology. We could potentially get better results if we knew exactly how long it takes us personally to fully recover and be ready to train again without fatigue, and avoid exhaustion and overtraining in the long run. And if we could correlate our physiological levels of fatigue via saliva with more practical measures like heart rate and RPE, we may potentially be able to set optimal exercise intensity more accurately.
In addition to looking at the effects of different intensities and types of training on fatigue, researchers are currently examining biomarkers in saliva to investigate how various dietary and supplemental interventions – including carbohydrate, caffeine and creatine – affect fatigue. Interesting stuff!
Filed under: exercise research, news
