90 hours at over 40kph. Decreases in bone density.  Dynamic calculations on time cuts. Dramatic maximum heart rate drops. More than 5,000 calories a day. Completing a Grand Tour is tough and our sports science team of Neal Henderson and Mac Cassin dive deep into the details -- interrupted only by a few colorful stories -- to help you understand what it really takes.

**Learn more:**

https://www.wahoofitness.com/blog/numbers-takes-race-grand-tour/

**Try the SYSTM Training App free for 14 days.**

https://www.wahoofitness.com/systm/getting-started

Have questions? Please ask us here! 

https://wahoox.forum.wahoofitness.com/t/new-knowledge-episode-what-it-takes-to-ride-a-grand-tour/19028