The chart you see here is for one of my senior athletes from his 2009 state time trial championship, which he won. He didn’t do the race in 2010 due to an early season crash. His 2011 state TT is coming up next week and so I put this chart together as a lesson and reminder about race management prior to the race. You can click to enlarge it and then read the comments. I won’t go into them in detail here as they should be understandable.
What you may not understand is the chart layout and terminology based on WKO+ software. First of all let’s look at how the course was managed overall. Notice that the chart is divided into quarters of equal length (3.1 miles). He raced each quadrant with a plan for energy expenditure. Here is a quick explanation of the other chart details:
X axis: Time.
Red line: Heart Rate. Y axis on left side.
Blue Line: Speed in miles per hour. Y axis on right side.
Black Line: Power. Y axis on left side.
Green Line (mostly behind black line): Cadence (RPM). Y axis on right side.
RPM: Revolutions per minute. Pedal velocity.
VI: Variability Index. How steadily he produced power. 1.0 means it was quite steady. Anything in excess of 1.05 is too great for a TT (or non-drafting triathlon).
NP: Normalize Power. WKO+ determines this based on quite a tedious formula. It basically is what the rider “felt” the power was like. Another way of thinking about NP is that it is a proxy for the metabolic cost of the ride. NP is almost always higher than average power.
HR: Heart Rate average.
NP:HR: The ratio of NP to HR which is NP divided by HR. High numbers are good as they indicate high power output for a low effort input. The ratio is meaningful only to the given athlete and can’t be compared with another rider’s ratio.
Decoup: Decoupling. A comparison of the NP:HR ratio for the two halves of each quadrant. A rising number means that HR is rising faster than NP. I like to see this below 5% in an aerobic, steady-state race like a TT (or triathlon). That indicates aerobic fitness is sound. Tends to be high in early stages of the race (or workout) as heart rate is rising with warm-up (see Q1). It also increases as effort increases (see Q3). Negative decoupling (as in Q4) is good as it means HR and power are coming back together again as the segment/workout duration increases. This means the athlete has “settled in.”