Validity and Reliability of Three Commercially Available Smart Sports Bras during Treadmill Walking and Running

Abstract

A variety of wearable technology devices report heart rate. Heart rate sensing smart bras are manufactured for females who participate in activity, however accuracy has not been determined. the purpose was to determine the validity of heart rate measures in three commercially available sports bras during walking and running. twenty-four healthy females completed bouts of treadmill exercise. the Adidas Smart sports bra, Berlei sports bra, and Sensoria fitness biometric sports bra were tested. participant perception of each garment was obtained immediately after the participant divested the sports bra. The Adidas Smart sports bra was valid only during rest (Intraclass correlation Coefficient [icc] = 0.79, mean absolute percentage error [MAPE] = 4.5%, Limits of Agreement [LoA]=−8 to 8). the Berlei sports bra was valid across all conditions (icc = 0.99, MAPE = 0.66%, LoA = −19 to 19), and the Sensoria biometric bra was valid during rest and walking (icc = 0.96, MAPE = 1.9%, LoA = −15 to 12). Perception of the smart sports bras was higher for the Adidas Smart sports bra and Sensoria Fitness sports bra, and lower for the Berlei sports bra. Sports bra manufacturers designing wearable technology garments must consider the ability of returning accurate biometric data while providing necessary function and comfort to females engaging in physical activity.

Assessing Heart Rate Using Consumer Technology Association Standards

“…Accuracy was assessed for each device within each activity via mean bias, mean absolute percent error (MAPE), Bland-Altman analysis, an equivalence test, and intraclass correlation coefficient (ICC) using the two-way mixed model and absolute agreement in IBM SPSS (IBM Statistics version 26.0, Armonk, NY, USA). This analysis is consistent with previous literature employing multiple testing methods when aiming to prove that data are the same [6,14,20,21]. Equivalence tests were conducted using the two-one-sided-tests method with Jamovi statistical software [22].…”

Concurrent heart rate validity of wearable technology devices during trail running

“…Laboratory-based research investigations into wearable technology devices have generally utilized specific thresholds for validity measurements, such as ICC above 0.70 and/or MAPE lower than 5% [ 7 ]. While these thresholds are acceptable for controlled environments, wearable devices are being used in a variety of applications that do not offer the same constraints.…”

“…Validity was determined through multiple methods [ 6 ]: Bland-Altman bias and Limits of Agreement (LOA) for repeated samples with accompanying 95% confidence intervals (CI) [ 33 ], Mean Absolute Error (MAE) and Mean Absolute Percent Error (MAPE), Lin’s Concordance Coefficient (r C ), and Intraclass Correlations (ICC) (IBM SPSS, IBM Statistics version 24.0, Armonk, NY). Validity was considered if devices met all of the following criteria: MAPE within 5% [ 7 ], r C greater than 0.90 [ 8 , 34 ], and ICC greater than 0.70 with a p-value less than 0.05 [ 35 ].…”

“…Wearable technology devices that return heart rate include smart bras [ 7 ], earbuds [ 8 , 9 ] and sensors placed around the forearm [ 10 , 11 ] or wrist [ 12 , 13 ]. Several investigations have utilized treadmill running protocols when evaluating the agreement of heart rate compared with electrocardiogram (ECG) [ 4 , 11 , 14 , 15 ] or chest strap criterion measures [ 8 , 10 , 16 – 18 ], which will be taken as validity in the current investigation.…”

“…The purpose was to determine concurrent heart rate validity during trail running. Twenty-one healthy participants volunteered (female n = 10, [mean (SD)]: age = 31 [ 11 ] years, height = 173.0 [ 7 ] cm, mass = 75.6 [ 13 ] kg). Participants were outfitted with wearable technology devices (Garmin Fenix 5 wristwatch, Jabra Elite Sport earbuds, Motiv ring, Scosche Rhythm+ forearm band, Suunto Spartan Sport watch with accompanying chest strap) and completed a self-paced 3.22 km trail run while concurrently wearing a criterion heart rate strap (Polar H7 heart rate monitor).…”