Numbers Don’t Lie (except for when they do)

It’s Tuesday and I don’t have a race tonight!  The Over the Hump (OTH) racing series is on a three week summer hiatus and I couldn’t be happier.  As mentioned in my previous post (“Splat”) I’m worn down from racing and am looking forward to fun rides.  If my previous post was a qualitative description of how I felt tired then this post will quantitatively explore how/why my legs feel like soda left out in the open – flat.

We’re 7 months into 2012 now so I thought it would be interesting to analyze my training log.  In late 2011 and early 2012 I knew I needed to increase my workload (time, miles, and intensity) in order to compete at a high level in the US Cup series (Cat 2).  Having accomplished that, I know that to do well in CAT 1, which I’m upgrading to, I will again need to increase my workload. But I worry about doing this in a sustainable fashion – too much too soon and I fear burnout or injury.  So right now, while I’ve reduced my riding intensity and OTH is on break, is a perfect time to evaluate my training.

Racing mileage (green) in context with total 2012 monthly mileage. The US Cup Series stretched from March to June.  Wonder why I’m tired no more:  a third of my total June mileage was at race pace!

The chart above illustrates my monthly cumulative mileage and breaks it into racing miles and the remaining training miles.  It doesn’t show the end of 2011 mileage but the trend was LSD rides (LSD = long slow days) heading into January and February where I used the Racers & Chasers series and the 12 Hours of Temecula to add intensity and race sharpness.  Because there were three US Cup races in March my mileage volume decreased to compensate for the increase in intensity.  April and May both had two races so volume increased until we hit June when the mileage plummeted (remember the splat?).  I participated in 7 races in June!  33% of my June miles were at race pace!  Wonder no more why my body wants to rest . . .

Diving into this further and I find that 65% of my mountain bike miles are attributable to races in June.  Thus far, for the first six months of 2012 races have accounted for 40% of my mountain bike mileage and 15% of my total mileage (adding mountain and road miles together).  In addition to the physical adaptations this is forcing upon my muscles and cardiovascular system, the numbers put into perspective for me how all the racing can become mentally taxing.  It will be nice to just ride and not think about the spacing, frequency, intensity, and duration of rides to fit them around races and being “fresh”.

But mileage alone doesn’t really tell the story.  Workload can’t be defined by mileage.  Miles explain distance covered and imply work but not one mile is created equal.  Was the mile on road or dirt?  Was it uphill or downhill?  Bumpy or smooth?  With or against the wind?  Was the pace spirited or relaxed, consistent or punchy?  Was the mile covered solo or in the shelter of a group?  Mileage doesn’t capture intensity so as a way around this I have tried to adapt Joe Friel’s concept of a Training Test Score to measure and track the intensity for each ride I do.

Because I don’t have a power meter (for either road or mountain bike) and because I wanted to simplify Joe Friel’s approach I now calculate my own intensity factor using time spent in specific heart rate zones.  I’ve used Joe Friel’s methodology for establishing heart rate zones based off a lactate threshold test where you ride a 30 minute time trial and use the average heart rate for the last 20 minutes.  I last did this test in February and my LTHR (lactate threshold heart rate) was 165 bpm.  It’s probably higher now because my average HR from last week’s race (see below) was 165 bpm and that was for a 1hr11min effort!  So Note to self:  I need to do another LTHR test, but that’s for another time and blog.

At last week’s Over The Hump race I averaged 165 bpm and maxed out at 180. Ouch. So something tells me that my LTHR is > 165 bpm but I won’t know until I do another field test and I don’t want to right now because they – well – hurt.

So here’s how my intensity factor works:  I take any given ride and use multipliers for the time spent in each heart rate zone.  For simplicity, I’ve setup 5 heart rate zones with a 1 being a recovery ride and a 5 being a lung-busting muscle-shearing anaerobic effort.  (Note – there are many resources to help you figure out how to break up your heart rates into appropriate zones & the links above to Joe Friel’s blog and books are fantastic.)  So  keeping in mind I’m using my heart rate zones, here’s an example of a ride and how I convert it to an intensity factor.

On a recent fun mountain bike ride that had a mix of climbs and descents I rode 13.6 miles and climbed a total of 1,430 feet in 1 hour, 16 minutes and 28 seconds.  I calculated the intensity as such:

  • 4 minutes in zone 1 = 4 x 1 = 4
  • 34 minutes 19 seconds in zone 2 = 34.32 x 2 =  68.64
  • 22 minutes 9 seconds in zone 3 = 22.15 x 3 = 66.45
  • 16 minutes in zone 4 = 16 * 4 = 64
  • Adding it all up = 203.09

It makes sense in a way when looking at this that the workloads spent at zone 2, 3, and 4 are similar despite the unequal time spent in each zone.  Put another way, I can accomplish similar work in less time in zone 4 than I can in zone 2.  Extending this thinking to different rides and you can see how an hour race can strain the body as much or more than a two or three hour recreational ride!

I track my weekly intensity and use it to help me assess my workload and plan my training.  The graph below highlights the cumulative weekly intensity in grey bars (units are in minutes) with the total weekly minutes in the green on the left axis.  The blue line provides a look into what my minutes are buying me on the right axis (more on that in a bit).  You’ll notice the grey bars oscillate back and forth, particularly in recent weeks (weeks 19-26), as I’m balancing big race weeks (high effort, low volume, shorter rides) with training and recovery weeks (low intensity, low to medium volume but longer rides).

Weekly Intensity Log tells a more complete story of how stressful a given weekly workload on the bike is.  I calculate an intensity factor based on heart rate zones since I do not have a power meter.  This way I can better track weeks in which I work harder than others for better training and recovery.  Miles and minutes are not created equal so by logging my intensity (time spent in particular hear rate zones) I can wrap my head around how hard I am working (or not).

Again, keeping in mind that no mile is the same just like no minute spent pedaling a bike is the same, total minutes (green) doesn’t tell the complete tale which is why the intensity calculation (grey bars) helps.  But because it’s hard to wrap my head around the intensity units (how long is 1500 minutes and what exactly does that mean?) I created the blue line which divides total weekly minutes by weekly intensity, giving me a ratio.  A high weekly value for the blue line means that week was filled predominantly with minutes spent in the lower training zones.  A low value represents a week filled with an intense (high HR) workload.  An example will help.

Week 23 has the lowest Minutes to Week Intensity value this year (0.268) because the total weekly minutes of 355 minutes (5 hrs 55 min) came as a result of 3 “rides”, two of which were races.  One of the races was a 12 hour race in which I rode for over 4 hours on a coed team all at LTHR while the other was an Over the Hump race.  The remaining ride was an hour spin in heart rate zones 1 & 2 the day before the 12 hour ride to check on my racing rig’s drivetrain.  So most of my minutes that week were in the higher zones with the higher intensity multipliers.   While my total minutes were low, those few minutes were mostly at LTHR so my workload (or intensity) was high.  Contrast that with week 24, which was a recovery week from the efforts explained above, so my minutes increased with long slow rides.  That week I had 5 rides, only one of which was a race.  Most of the rides were road-based and focused on keeping the heart rate low.  Because the HR was kept low and I logged a decent amount of minutes my minutes to week intensity value spiked.

Moving forward, I am going to build back my base logging more road rides while keeping the intensity down. I should see the gap between the green line and the blue line decrease as my rides become more moderate with less variability between full throttle and recovery.  I look forward to this!

Happy 4th of July to all!

One response to “Numbers Don’t Lie (except for when they do)

  1. Pingback: 2013 Training Review & 2014 Planning (part 1) | natespin·

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