— Health and Wellbeing
Biosensor tattoo tells athletes when they're about to hit the wall
The lactate-monitoring biosensor tattoo on one of the test subjects
No athlete likes hitting “the wall.” You know, that point at which their energy level suddenly plummets, and they just can’t go on. Using something that looks like a temporary tattoo, however, they may soon be able to receive a warning when they’re approaching that threshold.
The hitting of the wall occurs when sustained vigorous physical activity causes lactate to build up in the body. When lactate levels get too high, fatigue results. By monitoring those levels, however, athletes can ease back on the activity, allowing their lactate levels to drop before reaching that point of no return. Unfortunately, real-time monitoring currently involves blood tests, or the use of bulky equipment.
As an alternative, a team led by the University of California, San Diego’s Prof. Joseph Wang has created a flexible electrochemical biosensor. Applied to the skin, that temporary-transfer sensor continuously measures lactate levels in the athlete’s sweat. When used on 10 test subjects who were working out on an exercise bike, it was able to accurately indicate the rise in their lactate levels.
Prof. Wang hopes that the technology could be used not only in the training and performance tracking of athletes, but also for soldiers and other people who are required to perform intense physical activity. Wang has previously brought us such innovations as smart underwear, a bubble-propelled gut rocket, and another tattoo-like sensor that detects metabolic problems.
A paper on his latest research was recently published in the journal Analytical Chemistry.
Source: American Chemical Society
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
Would like to see this on the market in a reusable form with replacement batteries, like a chest strap for heart rate.
In fact it may be integrated into a module that can actually tuck under a chest strap.
A display (hud, watch form, external screen, etc) can provide user formation. Haven't seen how granular it is, but it would be an ideal tool to indicate physical fatigue, giving the user a heads up to recover.
The mechanics of 'the wall' are actually a bit strange and I'm surprised they are not discussed in more detail.
To elaborate, a few years back I did a white water event over a 400km stretch that lasted three days.
Each day, in the first 20km of the run you would feel a build-up of pain in the arms, which would hit a peak. This was a well known phenomenon, and all parties indicated it is something you can push through. Sure enough, as long as you continued to paddle, the pain would go away.
Beyond that point, you would be good for between 1-2 hours before the next one hit. The second would generally be a lot worse, with a peak that lasted much longer (15-20 min), but it would also go away.
By this point, you could go for a few hours, but would reach lunch time, and take a break for a snack, and a slow paddle for 20 odd minutes to avoid cramps after food.
The afternoon paddle would usually be more brisk, and last several hours, but this wall when it came would not be lactic pains, but in the form of complete lethargy. Your arms basically turn to jelly, and you have to wind it right down and go for a 10 min alternating power paddle followed by 5 min of rest paddle. Glucose tubes would help for some recovery, but they take 20-30 min to be adsorbed.
By the end of the day ~1700 you would be completely wrecked, and fall asleep by about ~1900
The fastest time was the second day. Slowest was the first. Third day was somewhere in between.
In conclusion, there are more factors that play into how your body behaves to different scenarios, and I would welcome a combined interface that monitored lactic acid, salts, hydration, glucose, blood pressure, heart rate and Vmax in a combined interface that displayed your true condition.
Good points Nairda, as a weekend warrior marathon runner, I would love to have a comprehensive assessment of all factors contributing to my condition and avoid the common cramping conditions and lack of movement at mile 18-26.2
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