Anaerobic threshold (AT) is one of the most common and useful performance markers used by many athletes and coaches. Anaerobic threshold also referred to as the lactate threshold (LT), is a popular method of improving high-intensity endurance performance. Athletes often use their AT to determine how to train and what sort of a pace they can maintain during endurance sports.
What is Anaerobic Threshold?
An athlete’s anaerobic threshold occurs when the body transitions to burning glucose and glycogen as a fuel source. As an athlete engages their type 2 muscle fibers through high-intensity work, their body breaks down glucose for energy, and a by-product is lactate. When the athlete’s energy expenditure is relatively easy, generally a three or four out of 10 on the Rate of Perceived Exertion Scale (RPE), the body recycles and reuses the lactate produced back into energy and effectively releases the waste products (Soultanakis, Mandaloufas, & Platanou, 2012). Through this phase (aerobic), the production of lactate remains moderately constant. As the athlete speeds up there is an increased demand for energy and the production of lactate increases. At some point, whether it be holding a steady pace for too long or going too fast, the production of lactate will continue to rise, and the body is no longer able to convert lactate back into energy and expel the waste products. An athlete generally reaches this point at or close to 7 out of 10 on the RPE scale. This point is referred to as the anaerobic threshold.
How can an athlete improve performance through anaerobic threshold?
The ability to sustain high relative power and energy outputs is clearly important for endurance performance. For example, at the beginning of the triathlon race season, a triathlete may be able to maintain 20 mph on the bike and run a nine-minute mile. Throughout the season increased threshold interval workouts, allow the body to get stronger and adapt to the increased production of lactate. This theoretically increases the cycling threshold pace to 23 mph and decreases the running pace to 8:30 per mile. Since the threshold is higher the athlete can cycle and run faster with less effort which allows for fuel to be burned more efficiently throughout the entire race.
One method of improving an athlete’s anaerobic threshold involves training at or near their threshold. At this intensity, an athlete is putting a significant amount of stress on the system without going over the lactate tipping point. These workouts are often called threshold workouts, tempo runs, or tempo intervals. Another form of workout is known as high-intensity interval training (HIIT). For these workouts, intervals are comprised of alternating short, high-intensity sessions followed by periods of active recovery. Typically, the high-intensity portion of the workout is performed at levels above the lactate threshold.
Anaerobic threshold (AT) is one of the most common and useful performance markers used by many athletes and coaches. The development of an athlete’s anaerobic threshold can be one of the easiest ways to improve performance and see gains throughout the season.
References
Soultanakis, H. N., Mandaloufas, M. F., & Platanou, T. I. (2012). Lactate threshold and performance adaptations to 4 weeks of training in untrained swimmers: Volume vs. intensity. Journal of Strength and Conditioning Research, 26(1), 131-137. https://doi.org/10.1519/JSC.0b013e31821eb7bd
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Kristen Hench
Kristen Hench, Ph.D., is a certified coach through USAT, USAT Para, ACE, USAC, ASCA, ASFA Yoga certified, and is a RRCA certified race director. She has trained beginner through elite athletes helping many to reach podium finishes as well as meet their personal goals in triathlon, running, track, and swimming. Kristen coaches adaptive sports with the USAF AFW2 program as a cycling coach and also works with a variety of able-body and parasport athletes through TRIMotion3. She enjoys helping children and youth get healthy, learn new life-long skills, and build confidence. She has coached internationally and was selected to coach in the 2018 and 2020 Invictus games. Kristen has also directed numerous family races and competed in several triathlons herself, including the Ironman distance events. She placed in the top three for her age group in the inaugural year of the Mountaineer Half Ironman and was one of the top swimmers in the 2004 Lake Placid Ironman. Besides triathlons, Kristen also enjoys marathons (with a PR of 3:15), triathlon, swimming, and a multitude of boot camp activities.