Wearables & fitness technology
Decision path
We start with what the equipment does, compare the trade-offs that matter, then assess individual products. Retailer descriptions are a source to verify, not our verdict.
Reviewed guidance available
Only guidance and product assessments that have completed our evidence and editorial checks appear here.
Worth it if you train by heart rate and want the reading right, not if you pace by feel. Wrist sensors read low at higher efforts and misjudge many hard effort minutes. A chest strap reads the heart's electrical signal directly and tracks intervals more accurately.
Read the articleA modest tool for endurance athletes, oversold for everyone else. A pooled analysis found training guided by morning heart rate variability gave a medium improvement in submaximal fitness markers, but no real edge in race performance or VO2max over a good fixed plan.
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