Sweet spot : the efficiency zone
LoadAn intensity just below threshold, roughly 88-94% of FTP or CSS.
Sweet spot offers the best stimulus-to-recovery ratio. Sweet spot sessions usually run 20 to 60 minutes (often in intervals) and don't crush you for days like pure threshold work.
In TriPaced:
In TriPaced, sweet spot shows up in build weeks as an alternative to pure threshold. It accounts for a significant share of bike and run volume as a long race approaches.