Is it enough to use an anti-fatigue mat at a standing desk, or do I still need an ergonomic chair?

An anti-fatigue mat addresses standing fatigue only — it does nothing for the 60%+ of your workday you're likely still spending seated. The two serve completely different postures and are not substitutes for each other. A proper ergonomic chair handles seated support; an anti-fatigue mat handles standing comfort; together they cover your full workday. Skipping either one creates a gap in your ergonomic setup. FindOfficeFurniture.com has ergonomic chairs and accessories at great bundle prices — call 888-719-4960.