I've been using a piece of software called SportTracks to help me train with a little more insight. Here is what the last two months of training looks like, as I got ready for the JFK 50 mile run yesterday.
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| SportTracks 3 with the Training Load plug-in |
This thing doesn't exactly speak for itself, but there is a lot of information presented in a way that makes you think a little differently about what you're doing to prepare for a big event. Here's what is being shown.
First, the vertical bars represent individual training days. Three of the taller bars are labeled A, B, and C - these are a 22 mile training run on the Appalachian Trail, a 50 km trail race, and the Toronto Marathon respectively. The height of the bar is calculated based on time and intensity, a function of the number of minutes spent in each heart rate zone, so that longer duration events at higher intensities get a higher "training impulse" (TRIMP) value.
Over a period of time these individual training days average out to some 'chronic training load" (CTL), shown above as the blue area under the line labeled '1'. As our training load increases through a training cycle, you would expect to see this line gradually increase over time.
The red line labeled '2' above is similar, but is called the 'acute training load (ATL). While the CTL is a long-term sliding average of you daily training level, the ATL is a short-term sliding average telling you how what you have done recently compares to the long term. Seeing ATL higher than CTL means your recent training has been harder than average. It also means you are relatively fatigued, and not ready to perform at your best. The green line labeled '3' is a plot of 'training stress balance' (TSB) that just represents this difference between ATL and CTL ... when the line is positive, you are relatively rested or recovered, and when the line is negative your are fatigued and not ready to perform your best. You can see on the chart above where leading into the Toronto Marathon (the bar labeled 'C') I took a couple of days off from runnng, causing the ATL line to drop and the TSB line to go positive. At the far right side of the graph, the day before the JFK, I am also pretty well recovered with a very positive TSB value.
The final curve shown on the chart is called an"influence' curve (labeled '4'), plotted based on work described in this paper -
Influence Curves.pdf. This curve is not at all affected by how you are actually training, it simply attempts to show when you should be training to best influence you performance on a selected target date. In the graph shown, the target date is the day of the JFK 50 on the right side of the graph. Not surprisingly the value is positive in the two months leading up to the target date, telling me it's a good time to be preparing. You can also see a peak in the curve, indicating the most critical time period for training. About 11 days ahead of the event the influence curve actually turns negative, indicating major training effort this close to the event will not help your performance at all - during this period you are better off doing low intensity efforts that slow the loss of fitness level you've achieved while allowing recovery.
Now that you have seen the charts, feel welcome to critique my preparation for the JFK 50. My current thinking is that I'd like to see more regular and definite recovery periods during a training cycle.
