The first big gravel monument of 2021 is done and dusted. After a grueling day of riding across the hot, windy, and at times chunky gravel roads of Kansas’s UNBOUND Gravel signature event, Wahoo athlete Ian Boswell took the top step of the podium in the 200-mile race with a winning time of 10:17:24.
We’ll take an in-depth look at Ian’s power output throughout the race, as well as compare his values to another competitor in the 200-mile UNBOUND event: Wahoo Sport Science’s own coach Jeff Hoobler, who took 6th in the Men’s 50-54 race (74th overall) with a very respectable time of 13:18:03.
Summary statistics
|
Ian |
Jeff | |
|
Total Time |
10:17 |
13:18 |
|
Average Power |
247W (3,4 W/kg) |
143W (2,2 W/kg) |
|
Total KJ |
9.106 Kj |
6.779 Kj |
While the finish times for Ian and Jeff differed by just over three hours, both athletes worked at a very similar average power output relative to their FTP over the course of the race. Ian averaged 62% of his FTP, while Jeff averaged 61% of his FTP (though Ian did hold higher average watts per kilogram).
Power output during a race is typically more variable than if you were just holding steady power on a trainer. Because of this variability, Normalized Power (NP), which gives more weight to harder efforts, is a more accurate measure of physiological stress. In this case, Ian’s NP for the race was 280W, which is 70% of his FTP while Jeff’s NP was 173W, equating to nearly 73% of his FTP. From these summary values, you could conclude that both Ian and Jeff worked similarly hard, on average, relative to their own sustainable power (FTP) for both average and normalized power.
In terms of energy expenditure, we usually look at kJ expended—though you can consider kJ of energy expended approximately equal to a Calorie of energy. While Ian expended more total energy than Jeff due to being a bigger rider (72kg vs 66kg), he also burned more energy per hour than Jeff with 887 kJ (calories) / hour for Ian, compared to 510 kJ (calories) / hour for Jeff. The total energy burned is important to consider when thinking about fueling strategy (see below). Keep in mind that in race situations it’s nearly impossible to eat as many calories per hour as you burn. How much of that energy burned comes from carbohydrates and fats is dependent upon how hard you are working (higher intensity = more carbohydrate) and your training status & physiology (the more aerobically fit you are, the greater amount of fat that your body can use as fuel for a given intensity of effort).
|
Ian |
Jeff | |
|
Peak 5 second |
1026W (100% NM) |
549W (66% NM) |
|
Peak 1 minute |
515W (77% AC) |
315W (69% AC) |
|
Peak 5 minute |
364W (73,5% MAP) |
244 (80% MAP) |
|
Peak 20 minute |
314W (78.5% FTP) |
219W (93.2% FTP) |
|
Peak 1 hour |
295W (73.8% FTP) |
197W (83.8% FTP) |
Check out the Comprehensive Gravel Training Guide
The single most interesting thing that I see here is that Ian achieved his 2021 season highest 5-second power output during the final sprint to win the race! Being able to hit your highest power of the year after over 10 hours of hard riding and racing tells me that either Ian was completely on fire on race day (possible), or that he just doesn’t do too many maximal sprint efforts in training (more likely).
As a comparison, Jeff didn’t come to the line trying to outsprint a competitor. He hit his highest power of the race—just 66% of his season-high 5-second power—an hour and fifteen minutes into the race while trying to maintain his position within a select group. Ian also hit a higher 1-minute power value (77% vs 69%) during the race relative to his season-best, and that occurred during one of the short hills about 2 hours into the race. Jeff hit his highest 1-minute power of the day just 43 minutes into the race – again, trying to maintain his position early on.
Looking at the highest 5-minute, 20-minute, and 1-hour power it’s clear that Jeff produced power values closer to his season-high values in all of those marks compared to Ian. What that means is Ian saved a little more energy throughout the day than Jeff did. Interestingly, Ian’s highest 5-minute power occurred 4:41 into the race, while Jeff hit his highest 5-minute power starting at the 1:15 mark of the race. Jeff also hit his highest 20-minute power of the day starting at the same 1:15 minute mark, while Ian’s highest 20-minute power effort started at the 2:29 minute mark. Finally, Jeff’s highest 1-hour average power happened between the 45 minute and 1:45 minute mark of the race, while Ian’s highest hour of power occurred between 1:53 minutes and the 2:53 minute mark. There’s a saying in endurance sports that you can’t spend later what you didn’t save earlier. Ian did a better job-saving energy in the earlier parts of the race, which he was able to convert into better performance later in the day.
Summary Intensity relative to 4DP Power
With The Wahoo SUF Training App, we look at Four-Dimensional Power (4DP®) —specifically, a rider’s peak 5-second called Neuromuscular (NM or sprint) power, 1-minute Anaerobic Capacity (AC) power, 5-minute Max Aerobic Power (MAP), and sustainable power (FTP) as our reference points for targeting individualized training targets and to assess progress across those different durations during training.
When analyzing both Jeff and Ian’s files, we saw that the total work for each rider relative to their 4DP values was accumulated as follows:
4DP Target Contribution to Total
|
Ian |
Jeff | |
|
FTP |
63% |
56% |
|
MAP |
29% |
32% |
|
AC |
8% |
12% |
|
NM |
0,5% |
0,1% |
This confirms that while FTP is the predominant target intensity for both, there’s a very significant contribution from MAP intensity, and AC intensity that is required for success even in an ultra-distance race like Unbound. Also, note that the relatively small NM contribution still represents important efforts that helped both riders maintain position and in Ian’s case to ultimately win the race at the finish.
Fuel & Hydration
Ian
Fluids: 8 planned bottles half with SIS Beta Fuel/Half with the new Skratch SuperFuel (high carbohydrate) mix, plus three packs of LMNT salts split between the 6 bottles. 2,5 x 1.75-liter hydration packs. 2 unplanned bottles filled at mile 125.
(Note: Ian peed 5 times from the bike during the event.)
Food: 8-10 Picky bars, 3 SIS gels, 4 packs of GU chews. 4 sticks of Extra chewing gum!
Jeff
Fluids: 14 X 20-ounce bottles (10 Skratch drink mix/4 water); 3 X 100-ounce water refills of hydration pack; 5 X cans of Coke. (Note: Jeff didn’t pee the entire race.)
Food: 10 X rice cakes; 5 X Lara bars; 3 X Skratch bars; 4 X Skratch chews; 2 X Gels; 3 X Skratch sport crispy rice bars.
|
Ian |
Jeff | |
|
Total Fluid (ounces) |
345oz (~10,3 liters) |
650oz (~19 liters) |
|
% Sports Drink/Coke |
46% |
40% |
|
Total Calories Drinks |
~2.200 |
~1.635 |
|
Sum Liquid + Solid Calories |
~4.900 (475 kcal/hr) |
~4.835 (360kcal/hr) |
The biggest surprise here is that Ian actually ate/chewed 4 pieces of chewing gum. But seriously, it’s just amazing to see the amount of fluids necessary for the riders – with Ian taking in just about 1 liter per hour (33,9 ounces), his total fluid intake was over 22 lbs of fluid throughout the day. Jeff likely has an even higher sweat rate (which is a variable, individual factor) and had to take in 1,4 liters per hour, totaling over 40 lbs of fluid intake throughout the day, and still didn’t have to pee the entire time, while Ian peed five times!
Training and Preparation
|
Ian |
Jeff | |
|
Average Weekly Hrs for 4 Weeks Prior |
18,7 hrs (17,2/18/21/18,4) |
11,4 hrs (9,6/12,7/13,2/10) |
|
Longest Training Session in 4 Weeks Prior |
5:33 (Rule of Three race, 100 mile) |
7:42 (CO2UT race, 125 mile) |
The important takeaway here is that it’s not necessary to slog extra long weeks of training, nor include a single epic long ride in order to have success in long-distance events like UNBOUND. Ian logged just one week of 20+ hours of training in the 4 weeks leading up to the race, and his single longest ride in that 28-day period was just 5.5 hours (during the Rule of Three 100-mile race). Jeff balanced his work, family responsibilities, and training with an average of 11,4 hours/week for those same 4 weeks of training with his largest week totaling 13,2 hours, and his longest session of 7,7 hours at the CO2UT 125-mile race a couple of weeks before UNBOUND.
Train and prepare for your next gravel event using the Ian Boswell Gravel Training Plan.
