"You know that you've got the right weight when people ask you: "Are you ok"?" So said my club mate Jason Kehoe recently and his words were echoed in "Running with the Buffaloes" by coach Mark Wetmore: "Leanness is underrated," he says: "I tell people: "Go look at Track and Field News. See what those people look like. You should look like a skeleton with a condom pulled over your skull." (Lear 2003, p. 201).
So sitting here reviewing Matt Fitzgerald's latest effort (after "Brain Training for Runners") "Racing Weight - How to get Lean for Peak Performance", optimal performance weight is a topic I'm passionate about and a one I think it is fundamentally important element to master for the aspiring competitor. To add a picture point, look at the 2008 incarnation of yours truly left (5th in the Wicklow Way Trail, regular top-20) and the 2009 incarnation right (not within earshot of similar performances), a good example of Skeletor vs. Chubby-Go-Lucky!
The maths are very simple and Matt jumps straight into this during his foreward on page 3: "For example, a runner weighing 160 pounds has to muster about 6.5 percent more energy than a runner weighing 150 pounds." (Fitzgerald 2009). This is potentially a 0.65% performance reduction per pound of extra body weight or just over 0.29% per kilogram of extra body weight (own rounding). Remember these numbers, we shall come back to them later.
Body weight, body fat and endurance performance
I have stolen the title of the first chapter of "Racing Weight" for this section as it encompasses the holy trinity of finding your optimal performance weight, a term Matt defines thus: "that is - the weight associated with your highest athletic performance level". (Ibid, p 21).
In this chapter Matt looks at the bodies of several types of male and female elite athletes from different endurance sports (from cross-country skiing to rowers and triathletes). Not surprisingly "top distance runners are notoriously light and skinny" (Ibid, 15). Male elite marathoners were measured as having 3.3% body-fat and female distance runners as having 17.3%. The men's score is the lowest of all endurance athletes whereas the women's figures ranks them third (after bodybuilders and pentathletes). (Ibid, 16).
In addition, elite distance runners are of average to above average height for women with the men shorter than average. All have narrow hips, shorter than average feet, and carry a disproportiante amount of their lower body mass in the upper thighs as opposed to lower legs and shins (I suddenly take a lot of consolation from being a narrow-hipped 5'11'' with tiny size 8 feet and feeble looking skinny lower legs). (Ibid, 17).
A specific study for runners found that a 5% increase of body-weight leading to a 5% decrease in performance on a 12-minute test. This relationship may prove slightly different for additional gains (or smaller gains) as the relationship between body weight and performance may not be linear.
Another word of caution on using simply "body-weight" comes from the fact that its not just your optimal body weight we are looking at but your optimal body composition. (Ibid, 22).
Optimal Body Composition
"If you're close to your ultimate performance level, you are close to your optimal performance weight" (Ibid, 23)."
At the conclusion of my Lydiard experiment I had dropped down to around 68 kilos with a body-fat percentage of 8%. After Christmas and injury woes I weigh 69.9 kilos and have a body-fat percentage of 9.9%. The only good news is I have maintained what seems to be my standard muscle mass: 45.3%-45.5%. In the terms above, this increase of 2.8% is roughly equal to a 2.8% decrease in performance (1 minute 7 seconds for a 40-minute 10k runner for sake of example).
The first step in Matt's system is to "Find Your Racing Weight". He offers a lot of advice on how to do this and its not an exact science. You can use the guidelines for runners above but keep in mind its hard to reach that level as a non-elite Westerner and you may want some more realistic intermediate goals.
The book offers guidelines on how much you should aim to lose depending on what percentile you are in for your age group. My current body-fat percentage places me in the 90-95th percentile for the group of 30-39 year olds. (Ibid, 39). According to the book, athletes in this category should not generally actively try to lose weight (I'm in a grey zone where I could target moving up one row to the 5.2% in the 99th percentile but this can generally be done through training alone because the initial body-fat level is so low).
Luckily, I remember my optimal racing weight as being the 65 kilos and 6% body-fat measured by Emma Cutts of PeakHealth in Spring of 2008 during my best run of performances. With this numbers I can find what Matt refers to as your "lean body mass" (body mass that is not fat). To calculate a healthy target number you multiply your current lean mass (90.1% for me, or 100% minus my body-fat percentage, e.g. 100%-9.9%) with your weight:
- 69.9 kilos x 90.1% = 62.98 kilos
Then find your optimal lean body mass (100% minus the "targetted body fat percentage" or 6%) and divide your lean body mass by this figure (since you shouldn't be losing bone and muscle weight):
- 62.98 kilos/94% = 66.99 kilos
This means at the moment, I should look to lose 2.91 kilos (or just roughly 3 kilos) all fat. The reason for not going for 65 kilos directly is that this may cause me to lower my muscle-mass more than is healthy (I may have more effective muscle than in 2008, in fact, I think this is likely from empirical evidence). Once at 6% I can revise whether I feel I could move on to the 3% of the elites.
For sake of reference, bringing my lean body mass up to 97% rather than 94% would require me to drop to a body weight of 64.93 kilos (a loss 4.97 or 5 kilos). Basically, I could do with losing 3-5 kilos in light of the findings of this system.
Remember the 0.29% lost energy per extra kilogram carried? Well that means I could potentially reduce my energy expenditure from extra weight carried by 0.87% to 1.45%. In case you are still not convinced, this is the expected improvement it would have carried into my ill-fortuned Leinster League campaign of 2009:
As you can see it doesn't suddenly turn me into a world-better (only 100 mile weeks can do that) but it would have masked some of the reductions caused by last year's poor fitness development from my side (indeed I would have PBed Scarr and Brockagh). Note that the figures are underrated though, as I was closer to 71 kilos and 12% body-fat in the Summer of 2009 than 69.9 kilos and 9.9%).
Finally, the performance increase will invariably be higher in hill running as the cost of running uphill is exponentially increasing as the ascent grades increase and I need not say the further down the pack you are the more time you'll gain (percentage will be of a higher figure) and the more places will likely follow.
In my next article on Racing Weight, I'll look at the remaining chapters of Matt Fitzgerald's book: Five Steps to Your Racing Weight and The Racing Weight Menu. As a final preview, let me share the titles of the five step plan:
- Improve Your Diet Quality
- Balance Your Energy Sources
- Time Your Nutrition
- Manage Your Appetite
- Train Right
Sounds simple aye! Well, it isn't quite, so see how I do in creating a plan to follow these five steps in 2010 and reach my OPTIMAL PERFORMANCE WEIGHT.