WHY IS A LAB LACTATE TEST WORTH THE PAIN?
I recently went to the relatively new and categorically state-of-the-art CU Sports Medicine and Performance Center (CUSMPC) for some physiological and metabolic testing. Before the testing, I was taking on a tour of CUSMPC. I had *no idea* that I had access to a world-class sports performance facility practically in my backyard. In addition to physio and metabolic testing for bike and run, CUSMPC houses orthopedic surgeons, physical therapists, an AlterG (anti-gravity!) treadmill, two methodologies for high performance bike fits, running gait analysis, swim stroke analysis and physio testing, and cycling classes (think spin classes but BYO bike). All of which is open to the general public. Who knew? Clearly not me.
But back to the matter at hand …
WHAT IS IT?
The physiological and metabolical performance testing done at CUSMPC measures your heart rate, blood lactate levels, fat and carbohydrate oxidation rates, and VO2 across a spectrum of workloads – either paces on the run, or power outputs on the bike – with the goal of scientifically determining your individualized heart rate, pace, and power based training zones as well as establish ideal racing paces. The tests are conducted by Jared Berg, a certified strength and conditioning specialist as well as a former pro triathlete and current coach, and have been tailored by him to reflect the physiological demand of endurance events.
Even if your eyes glazed over as I described the testing, what should have jumped out was the idea that your ideal racing paces can be scientifically defined based on your physiological and metabolic profile.
WHY SHOULD YOU CARE?
If you’re looking to run and ride recreationally, and participate in triathlons for fun and fitness, then maybe you don’t care about your dialing in your training zones and race paces. But, if you’re starting to get serious about improving your performance, these pieces of data are pretty critical.
Many of us do field tests (such as 20 minute time trials for the bike and 5k time trials for the run) to estimate our lactate threshold heart rate (LTHR), functional threshold power (FTP), and run threshold pace. We then use these results to determine our training zones (more on that here). This is an easily repeatable and cost-effective approach – and a good start.
The results of field tests aren’t going to be as precise as a lab test, but typically – about 80% of the time, according to Jared – are reasonably accurate. What tends to be less accurate / less personalized, are those standard percentages that you use to set your training zones. Just check out how drastically my heart rate zones (left) and power zones (right) changed in the chart below. The blue zones are based on the standard percentages, and the green zones are the personalized zones set by Jared, based on my testing. Training zones are definitely not one-size-fits-all.
HOW DOES IT WORK?
Your time with Jared at CUSMPC will start with a weigh in and caliper test to measure body fat percentage, and some guidance on where you’ll want to be by race day. (Compared to my scale at home, I weighed in a few pounds heavier but my body fat came in a few percentage points lower, so: Win!)
We then set up my tri bike on CUSMPC’s Wahoo Kickr and I warmed up at a super easy effort level for a solid 30 minutes. (You can also use their spin bike with a built-in perfectly calibrated power meter, or you’ll be on a treadmill for the run test.) Once I was sufficiently warmed up, Jared had me don the only moderately annoying mask, necessary to measure oxidation rates. We then kicked in with the test: intervals of either five or ten minutes, at increasing power levels, and ear pricks for blood samples every five minutes. Just ‘cause sweating your ass off while breathing through a mask isn’t quite enough fun for one day. All-in-all, I was on my bike for well over an hour, and given the effort level of the test was totally able to use that as my bike workout for the day.
After the test was over, I cooled down and Jared used that time to run all the numbers. That’s where the real insight comes in. Once you’ve changed out of your sweaty, smelly bike clothes, you’ll sit with Jared in a consult room and review your test results. Jared first takes the time to provide background on things like typical lactate profiles across a range of athletes before diving into your specific results. Then he’ll show you your data through a series of graphs, explaining and interpreting all the details and answering questions as you have them. In addition to providing your lactate threshold heart rate and functional threshold power, Jared will dial in your training zones, suggested race targets for power and/or heart rate, and race-day fueling guidelines tailored for your glycogen stores, race intensity and race distance. He also provides recommendations for your training – how much time to spend training in each zone to achieve your desired race results.
HOW DO YOU GET STARTED?
Signing up for physiological and metabolic testing at CUSMPC is beyond easy. Just go to the CUSMPC website, review the services, pick a time slot, and – viola! – you’re good to go. Wondering whether to do the testing on the bike or the run? Interesting question. I prefer the testing on the bike because the uncomfortable mask doesn’t drive me crazy as much on the bike as when I’m literally gasping for air on the run. Also, if you bike with power then you will definitely want to test on the bike so you can get your FTP checked as well as your LTHR. If you still can’t decide, I’d go with the discipline in which you’d most like to improve.
Final tip: I highly recommend adding a sweat test onto your physio and metabolic testing. The sweat test will reveal your sweat rate and concentration, which then determines your fluid and sodium requirements during training and racing. That’s the kind of information that can save your race – it’s a no brainer add-on.