To the next level

When cyclist Nate Loyal was competing as an amateur road racer two years ago, he found he couldn’t gain speed no matter how hard he trained. “I started the season doing well,” the Santa Monica resident said, “but as the season went on, I got worse. I couldn’t do breakaways or chase anyone down. I had no punch.”

Loyal’s breakthrough came when he learned one simple number: his lactate threshold.

Once Loyal, 27, started training with that number in mind, he not only picked up his pace, he graduated from amateur road racer to the next level in racing: top amateur, or a Category 2 cyclist, the highest level in domestic racing. “It’s the greatest training tool I’ve ever had,” he said.

Although most serious exercisers know their numbers -- resting, target and maximum heart rate, performance speeds, weight and body fat ratio -- many don’t know their lactate threshold, or LT.

First used on top athletes in Austria, the practice of lactate testing became known among top endurance trainers in the United States in the late 1960s, said Robert Vaughn, an exercise physiologist with Baylor Tom Landry Fitness Center in Dallas. Today, most elite endurance athletes and coaches use lactate profiling as part of their training.

Now, however, because of greater awareness and the availability of do-it-yourself testing kits, more amateur athletes are getting tested -- or testing themselves. “Up till now, amateurs haven’t had an opportunity to get measured, because testing wasn’t readily available,” Vaughn said.

Lactate -- also called lactic acid -- is a byproduct of metabolism. The body produces lactate all the time, and more so when exercising.

When you exercise, your body breaks down carbohydrates, creating hydrogen ions that enter muscle cells. When these ions begin to accumulate, they make muscle cells acidic, which impairs cell performance. To reduce the acidity, the pyruvic acid in the cell combines with the extra hydrogen ions and turns into lactic acid, or lactate. The cell can diffuse lactate easily: The lactate hooks up with oxygen molecules, which are already in cells, and is transported out of the muscle cells into the bloodstream. Coaches call this process “clearing lactate.”

As long as there is enough available oxygen in the cells to move out the lactate, muscles do fine. But when the lactate overwhelms the oxygen transport system, which happens during intense endurance exercise, the cells’ acid level rises, causing the cells to stop working.

Sports medicine experts call that transition point “lactate threshold,” or anaerobic threshold. Push beyond that point, and you soon feel exhausted. The harder an athlete can work before this shift happens, the faster and longer he or she can go.

“If you’ve been anaerobic, you know you can’t stay in that state long. Your legs burn; you’re out of breath, and you feel like you could throw up,” said Vaughn, who is also chairman of training theory for the Coaching Education Division of USA Track and Field.

The only way to raise your threshold is to do a lot of training below it, say the experts. Besides training, other factors that influence a person’s threshold include conditioning level, age, gender and genes.

“Most athletes train too hard,” said high-performance endurance coach Gareth Thomas, who helped Loyal overcome his plateau and who is also head coach of the UCLA triathlon team.

When working at their lactate threshold, well-trained athletes can maintain their performance for an hour or more. “Once you feel the burning and nausea, you’re well beyond your LT,” Vaughn said. “Your performance started to decline well beforehand.”

To help raise an athlete’s threshold, Thomas starts by slowing them down for eight to 12 weeks to build their aerobic capacity.

“As people gain aerobic capacity through conditioning, their hearts pump out a little more blood with each beat, which sends more oxygen to the cells,” Vaughn said.

Like many athletes, Loyal was surprised his threshold was so low. Before he was tested, he was riding at an average heart rate of 150 beats per minute on his easy days; his heart rate should have been closer to 140.

Though training regimens vary depending on the athlete and the sport, in general, once athletes establish a good aerobic base, Thomas recommends that they spend 60% of their training time just below their lactate threshold, 30% working at it and 10% of the time working above it, each week. Vaughn’s formula differs: He tells coaches and athletes to train 10% of the time below, 10% above, and 80% at lactate threshold.

The gains happen fast, Vaughn and Thomas said.

When Loyal, also a USA Cycling coach, was first tested, his lactate threshold was low and his lactate production was high. He hit his threshold when he produced 180 watts of power on the bike. After eight weeks of training below his threshold, he hit his threshold at 220 watts.

On the road, that translated into the difference between doing a 40K race [25 miles] in 1 hour 2 minutes, to going the same distance in 56 minutes, or six minutes faster.

“My goal is to go as far as my genes will let me,” he said. “If it weren’t for this information, I wouldn’t make it.”

Good lactate tests can be hard to come by and aren’t routinely offered at the local gym. Serious athletes can, however, have the test performed at a major exercise training center or university. And because more athletes want to track their lactate levels, home lactate testing kits are becoming popular. “These easy-to-use gadgets are where heart rate monitors were 10 years ago,” Thomas said.

To get tested, runners work out on a treadmill, and cyclists on a stationary bicycle, or they can attach their racing bikes to a stand. Test subjects start working out slowly and every couple of minutes get a finger prick -- much like a diabetic uses for blood testing -- to test the blood’s lactate level. As the intensity of exercise increases, lactate rises.

“What you see is a baseline that starts to rise slowly as the athlete is effectively clearing lactate. Then you see a more rapid jump,” says Vaughn. “That jump is the LT.”

The test is also sports specific. That is, runners need to have the test taken while running, and cyclists while cycling. Triathletes need to know their threshold for swimming as well and train accordingly. The same athlete can have a very different result on a bike, on the ground and in the water.

Although some trainers will say they can get a good approximation of lactate threshold by measuring heart rate, respiration and rate of perceived exertion, others insist that blood testing is the gold standard. “People who try to approximate LT ... have to do some pretty wild guessing,” said Vaughn.

Training around her lactate threshold raised Ruby Evans’ game. The 33-year-old lawyer and cross-country mountain biker has been racing competitively for eight years, but she stopped making gains four years ago. “The things that had always helped me before weren’t,” the Santa Monica resident said.

She got her lactate profile and found that though her threshold was pretty high, her body was not clearing lactate quickly, which slowed her down. She worked with Thomas on lower-intensity training and interval drills that involved getting her heart rate high for brief spurts, so her body would get better at recovering.

“After that,” she said, “I went from an amateur, barely hanging on to the back of the pack, to a midpack pro.” Last year, Evans took second place in her division at the Masters World Championship in Bromont, Canada.

Of course, plenty of people get fit without knowing their lactate threshold, and the test isn’t for everyone. But it is ideal for the person looking to make the leap from exercising for fitness to exercising for performance, Vaughn said. Armed with a lactate profile, an athlete should seek out a coach who understands how to create a training program around lactate levels.

“The lactate level is the body’s chance to speak,” Thomas said. “The best athletes in the world have known this for a long time. Now more athletes want that edge.”