Obviously, I come from one background, and the people that design fitness equipment have been doing it for years and years, and they know what works and doesn’t work.

Armstrong is acknowledging the limits of his own expertise and the value of specialized, long-term experience. The quote contrasts a celebrated athlete’s “background” (performance and training) with the accumulated practical knowledge of professional equipment designers who iterate products over many years. Implicitly, it argues for humility and collaboration: elite users can provide feedback, but durable, safe, and effective fitness equipment depends on engineering, ergonomics, testing, and lessons learned from past failures. Read more broadly, it’s a statement about respecting domain expertise and not assuming that success in one field automatically confers authority in another.