Reliability and Validity of the SHFT Running Power Meter

Area of Science:

• Sports Science
• Biomechanics
• Wearable Technology

Background:

• Running wearables are increasingly used to provide performance metrics.
• The SHFT device is a novel wearable system measuring running power (PO) via accelerometers and gyroscopes.
• Validation of novel wearable metrics is crucial for practical application.

Purpose of the Study:

• To evaluate the reliability and validity of the running power (PO) output from the SHFT device.
• To compare SHFT-PO with established measures of physiological load during running.

Main Methods:

• Reliability was assessed by repeated outdoor running trials at two speeds (10.5 and 12 km·h⁻¹) on consecutive days.
• Validity was determined by comparing SHFT-PO with oxygen uptake (VO₂) during incremental treadmill tests.
• Data were collected from 12 men for reliability and 15 participants (8 men, 7 women) for validity.

Main Results:

• SHFT demonstrated strong reliability with coefficients of variance (CV) of 1.8% and 2.4% at 10.5 and 12 km·h⁻¹, respectively.
• A very strong linear relationship was found between SHFT-PO and VO₂ (r² = 0.54) within subjects.
• Within-subject analysis of treadmill tests showed a very strong linear relationship (r² = 0.80).

Conclusions:

• The SHFT device provides a reliable estimate of running power.
• A strong correlation exists between SHFT-derived running power and metabolic rate (VO₂).
• SHFT is positioned as a leading commercially available running power meter due to its accuracy and reliability.