Tyme Wear taps wearable technology market with app ready cycle clothing

The popularity of wearable technology has increased steadily in recent years, to the point that it is now big business. At the start of this year, Gartner, a tech-focussed market research company, estimated sales for wearable tech would exceed $80 billion in 2021. Of course, much of this is made up of smart watches from Apple, Garmin, FitBit and the like.

But, looking to carve a slither out from this whopping pie is Tyme Wear, a small company based in Boston, US. Tyme has been around since 2014, but much of that has been developing its core technology, a smart shirt. Last year the company was awarded a $1.4 million investment from an Icelandic investment firm.

CI.N caught up with one of Tyme Wear’s co-founders, Arnar Larusson. Arnar is a mechanical engineer by trade of Icelandic heritage living in the US.

What is the Smart Shirt?

Tyme Wear’s smart shirt is designed to be worn by athletes to measure their breathing in order to provide them with their unique training thresholds. Paired with a phone app (pictured right) Tyme Wear aims to provide near lab-quality insights that athletes can use to improve their training.

Why bother?

Tyme Wear’s smart shirt calculates a person’s First Ventilatory Threshold (VT1), Second Ventilatory Threshold (VT2) and VO₂ max. Typically these metrics have only been available through lab testing. Because of the difficulty in obtaining these thresholds, training has often relied on more easily obtainable measures of output such as heart rate and power (measured in watts via a power meter). Many of you will be familiar with the efforts required to estimate your threshold and in turn the corresponding zones by which you train.

The traditional methods to measure your training zones rely on estimates of how your body is working. Heart rate formulas rely on population averages and do not account for individual differences within the population. Arnar tells us that ‘in reality, the result you get from percent of HRreserve or an all-out 20 to 30 minute time trial is not reflective of your base endurance (VT1) or your VO2max ability. These formulas can be off by around 29% for the typical athlete. The ventilatory thresholds, measured by the smart shirt, are more reflective of how your body is actually functioning and we can measure each of your thresholds separately. Each zone is specifically measured for you and your unique physiology.’

Furthermore, standard formulas assume our thresholds are correlated with one another. In reality, they are independent. Arnar tells us that the relationship between ‘VT1 and VT2 is non-linear, and that relationship is not detected in heart rate or power thresholds … by using ventilatory measures we are measuring actual changes in the body’. What Arnar means by this is that while heart rate and power could rise steadily during a step test in linear fashion, the data from their smart shirt will show distinct points where breathing changes and different metabolic thresholds are crossed.

Technical Info

The shirt itself is designed to be as comfortable as any other performance shirt. There are soft sensors integrated into the clothing to measure the wearer’s breathing via the expansion and contraction of the chest cavity. Attached to the shirt is a pod which tracks the body’s movement in all three planes of motion, including elevation, ground contact time, airtime, cadence, and running power.

The Pod connected to the shirt is reasonably small, weighing 20g and measuring 6.3cm across. It will record for 22 hours, with 18 hours of storage space. The smart shirt is machine washable, tested to withstand at least 100 cycles, with Tyme Wear offering replacements if it breaks, no questions asked.

The Set-up

Users will need to complete a 15-minute step test to get their ‘Fitness Profile’ measured. This will be familiar to those used to using platforms such as Zwift, TrainerRoad or the like. Though Arnar tells us this ‘is not as demanding as a traditional threshold test.’ For those of you unfamiliar, you start at a low power output, you ride with the intensity increasing periodically until it is no longer sustainable.

From this data Tyme Wear offers a user their unique metabolic thresholds. These thresholds can be applied directly to your training, this says Arnar will give you ‘better knowledge of what pace, power, or heart rate you should target to be able get the most out of every workout.’

The app also provides opportunities for post-ride analysis and tracking training load and whether this is having the desired improvement over time.

Is it accurate?

Measurements are taken 250 times per second. Tyme Wear claims to be able measure Breathing Rate at 97% accuracy, Tidal Volume at 85%, and Minute Ventilation at 95%. Translating to being on average within 7bpm for VT1 and 6bpm for VT2 across 200 tests. Though not claiming to meet the same accuracy as the gold standard lab test (a metabolic cart), Tyme claims they are fairly close. Not having tested the product we can’t make any comments on this but their claims have recently been supported by legend of the field Dr Stephen Seiler on the not-so-peer-reviewed Twitter.

Additionally, a paper (still undergoing academic review) testing the smart shirt on runners found that it “is less valid but is comparable in reliability when compared to the gold standard … the Tyme Wear smart shirt provides easily accessible testing to establish threshold-guided training zones but does not devalue the long-standing laboratory equivalent.” (Gouw et al, 2021).

An advantage over the gold standard test is that it doesn’t require a lab setting. Athletes can build up a picture over time for themselves.

What’s next?

Arnar says they have been ‘doing a lot of work in the lab so that [they] can determine what effort level a person is at during any given workout using ventilation alone, without using power or heart rate. This is step two of product development, after threshold detection was completed earlier this fall. Ventilation analysis of workout data is likely to be released in early January. Then step three is to display this data in real time.’

At some point in the future Arnar would also “like to be able offer training advice and plans. We’ll get there, but we want to focus on the analysis first and helping athletes execute their existing plans at the right intensity for them.”

Membership is based on a monthly subscription model. Starting at $35 per month for a minimum of 6 months, going down to $22 per month if paying for a full 18 months.

Though no formal distribution agreements have been made outside of the US yet, Arnar tells us that they are looking to open up to Europe in 2022 and they are currently working with a few teams and athletes. For those interested in the wearable technology products contact [email protected].

 

References

• Wolpern, A.E., Burgos, D.J., Janot, J.M. and Dalleck, L.C. (2015). Is a threshold-based model a superior method to the relative percent concept for establishing individual exercise intensity? a randomized controlled trial. BMC Sports Science, Medicine and Rehabilitation, 7(1).
• Gouw, A., Van Guilder, G., Cullen, G. and Dalleck, L. (2021). The Tyme Wear Smart Shirt is Reliable and Valid at Detecting Personalized Ventilatory Thresholds in Recreationally Active Individuals.