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Chang et al. Soft Sci. 2026, 6, 29                                               Page 17 of 26





               Hydration status of the body and electrolyte management
               Sweat is an important medium for the excretion of metabolites and electrolytes during exercise. The dynamic
               changes in its components (such as lactic acid, glucose, electrolytes, urea, etc.) , secretion rate and total
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               amount are associated with the metabolic load, hydration status and physiological stress level of athletes.
               Wearable sweat sensing technology integrates multiple types of sensors to achieve real-time and non-invasive
               monitoring of multiple biochemical indicators (like glucose, lactic acid, Na  and K ). It accurately captures
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               the physiological responses under different hydration states, as well as the dynamic change patterns of
               Na /K  concentrations under hydrated and non-hydrated conditions. The technology enables accurate
                 +
                    +
               assessment of the dehydration risk and electrolyte loss characteristics for professional athletes, and therefore
               aids the formulation of targeted fluid replacement volume, timing and electrolyte supplementation plans to
               effectively reduce the risk of heat-related diseases such as muscle spasms and heat exhaustion . The
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               battery-free, short-range wireless communication microfluidic patch further expands the monitoring modes
               via integrating electrochemical detection (lactic acid, glucose), colorimetric analysis (pH, Cl ), and volumetric
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               measurement (sweat rate, total sweat volume) within a single device. Long-term tests reveal an explainable
               time-lag correlation between its sweat-based detection results and corresponding marker levels in blood.
               Employing the patch may offer objective clues for reasonably adjusting the interval time, training intensity
               and recovery interval, by recording the lactate-power curve and tracking the metabolic stress distribution
               and recovery process of interval training [143,144]  [Figure 2C].


               Regulation of the microenvironment for tissue repair
               The quality of tissue repair after local muscle-fascia injury directly affects the recovery process and re-injury
               risk of athletes. Traditional repair strategies mostly focus on mechanical rehabilitation training and lack
               precise regulation of the local microenvironment of the injured tissue. The development of mechanically
               active therapy provides a new route for precise tissue repair: by programming the local stress/strain state to
               optimize the mechanical microenvironment of the injured region, it promotes the healing of injured
               tissues [145,146] . It is anticipated to combine such active tissue mechano-modulation with wearable stiffness
               sensing to establish monitoring-intervention closed-loop injury repair strategy. Specifically, the healing
               status of injured muscle or tendon can be evaluated by wearable stiffness monitoring, and this in turn, based
               on biomechanical and mechanobiological pro-healing mechanisms, guides the rational design of mechanical
               loading parameters to accelerate healing and avoid scar formation [147,147] .


               AI-enabled multimodal tracking
               Unimodal fatigue monitoring technologies - particularly those based on sEMG - have long dominated the
               field. However, increasing empirical evidence suggests that reliance on a single physiological signal is
               insufficient for achieving stable and reliable muscle fatigue assessment. The limitations primarily include
               high sensitivity to inter-individual variability, limited capability in identifying transitional states, and
               susceptibility to motion artifacts during dynamic exercise.

               Combined with artificial intelligence (AI) algorithms, unimodal fatigue evaluation based on wearable sEMG
               sensing shows reasonable average recognition performance, however with substantial inter-subject
               variability . Specifically, sEMG coupled with support vector machine (SVM) achieves peak accuracy over
                       [35]
               90%, yet the lowest individual accuracy is merely < 65%. Compared to unimodal sEMG with temporal
               convolutional network (TCN) processing, a dual-modal TCN model integrating ECG and sEMG exhibits
               significantly improved fatigue classification performance, with an overall average accuracy of 88.5% and an
               inter-personal variation range of ~ 10% (> 20% for unimodal model). In another study, a multimodal
               framework integrating muscle thickness, joint angle, and sEMG is developed to reduce the false positive rate
               down to 3%, thereby enhancing the functional robustness under dynamic conditions and improving
               reliability in real-world training scenarios . Expanding multimodal frameworks to biochemical sensing, the
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