"Can you do three more minutes?" I winced my way through the end of a 30-minute blood lactate threshold cycling test inside a fluorescent-lit lab. The strain in my legs and pounding heartbeat made the 10 tiny pin pricks on my fingers feel entirely inconsequential. Coach Gareth Thomas, designer and operator of the Los Angeles-based Trio sports science and training center, supervised my discomfort with calm detachment. Like Count Rugen as he tortured Wesley in "The Princess Bride."
I grunted something incoherent, so Thomas increased resistance on the CompuTrainer and I pedaled ever harder. Not even a minute later, as my cadence dropped below Thomas' pre-determined baseline, the test was mercifully over. It only felt like one year had been sucked from my life.
I wanted to explore the potential benefits of lab-based lactate threshold testing in my never-ending personal quest for better training and racing data. I also sought a reason why my wattage on the bike had been consistently lower for the past several weeks than my targeted functional threshold power (FTP) goals. What I learned changed my training habits, but not in the way I expected.
Understanding your lactate threshold and VO2 max can help you make smarter training, nutrition, pacing and racing decisions. For the uninitiated, peak VO2 max measures the size of your proverbial racing engine. That's largely based on genetics. As part of a VO2 max test though, Thomas will see how much fat and carbohydrate you burn and when you stop burning it, along with the intensity at which you stop burning fat. The latter is referred to as anaerobic threshold. Knowing how you process carbohydrate and fat will enable you to better create a nutrition plan to sustain your desired race pace. And with better fueling comes increased performance—a supercharged engine.
A lactate threshold (LT) test measures aerobic efficiency and stability. Thomas notes that scientists are not quite sure exactly the depth of lactate's role in the body but he said it's a great marker for efficiency. In general, low levels of lactate are the sign of an efficient aerobic system. The LT test also measures steady-state threshold, which is the last intensity where lactate concentrations stay the same as time progresses.
"Training is about becoming a complete athlete, maximizing potential in all areas so that whatever engine you own can perform at its highest level," Thomas said. "To me, the lab is the number-one place to monitor, measure and access where you are at, so that you can play your way to optimal performance through correctly prescribed training."
Lab time costs money though. Provided you have a power meter and a heart rate monitor, the most common way to determine LT and Vo2 max zones is to perform a 20-minute or one hour field test for cycling or a 30-minute run test. These sessions will closely approximate your training zones. A blood-based test will more precisely confirm them, but at a higher price. Each Trio lab session costs $195, and Thomas recommends testing every 9 to 12 weeks to measure progress. He added that cycling data shouldn't be used to establish running zones and vice versa, so that's twice the fees to consider.