If you follow these posts, you know that I recently installed a power meter on my mountain bike, and began using it to study the demands that mountain biking requires for fitness. I installed it just before a trip to Arkansas, where my wife and I rode the Womble Trail, and I have since ridden several times at a local trail in Dallas, named Boulder Park. I’ve been riding with a Shockwiz Suspension Tuning device, front and rear, which has helped my comfort and confidence tremendously, but this weekend was the first time in a very long period, that I’ve gotten to ride for fitness and exertion, instead of just as a “Trail Tourist”. With the power meter and Xert on my Garmin 1000, I got some exciting insights, which I’ll be sharing.

Trails in Dallas resemble a small intestine; fit as many kilometers of trail in to the available acres or hectares. There’s little public land, and the trails are highly maintained by a responsible group of trail stewards under the leadership of DORBA.ORG. The trails are twisty, turny, curvy, with short sight-lines and lots of accelerations and braking. For this weekend of testing and tuning, I chose the “A” loop, with all of the “Red” options, which is found below on Strava.

Let’s first use Strava, since it breaks down the segments better than I can on Xert at this time. Here’s a block of my recent efforts over a known segment that mimicked my ride.

Specifically – take a look at the efforts that recorded wattage. Here’s a screenshot….

Now, the first thing to look at and consider are the average speeds. Mountain biking in Texas is so twisty and TRUE SINGLETRACK CYCLING, that it’s hard to get a good speed. By the way – if you look at that Strava segment, you’ll see that my fastest time this weekend, was about SIX MINUTES SLOWER than the fastest times ever, and about FOUR MINUTES SLOWER than some of the athletes I’ve coached (using Xert, interestingly enough).

But look at the correlation, or otherwise, between average power (with zeroes), and time. Specifically, look at my fifth-best time, and my 2nd-best time. The average power output was different by just ONE WATT, but the time split was OVER SEVEN MINUTES. Why? I can think of just one thing, and that’s BIKE HANDLING. And I think my bike handling was improved by the tweaking I was performing on the suspension, front and rear.

But I think there’s something else going on that is important, and I think Xert is the system to use so we can understand it, and improve.

Click here to see the mystery solved, plus some training tips for handling short, steep, punchy North Texas-style terrain in Part Two (Premium Content—subscription)