121 Conditioning 101 - Intensity

Send us Fan MailConditioning intensity can be divided into four domains: moderate, heavy, severe, and extreme. Moderate IntensityPersonal anecdote: walking to New York CityIn athlete language: "easy", "Zone 2"What it feels like: you can speak in complete sentencesTypical duration: 2+ hoursModerate intensity is below the first Lactate Threshold (LT1), which is the pace at which lactate begins its sustained increase. Below LT1, the body is working in a physiologically steady state. If you hold this pace for long enough, the limitation will become either injury, overheating, or depletion of fuel substrates like blood glucose, muscle glycogen and intramuscular triglyceride (this is why ultra marathons are jokingly referred to as "eating competitions", one study found that IronMan finish was predicted by calories eaten during the race, the more they ate the faster they went).If you do eat enough to keep your fuel substrates topped up, then eventually you encounter perceived limitations related to your neurophysiology, which feels like a loss of "drive" to keep going. Heavy IntensityPersonal anecdote: 10k rowIn athlete language: "medium", "kind of hard"What it feels like: you can speak, but only in one or a few words at a timeTypical duration: 40 minutes to 2 hoursOnce you speed up to a pace above LT1, your blood lactate will steadily climb. If you continue working at your heavy intensity, lactate will continue to climb and then settle below the second lactate threshold (LT2).These paces require more effort to maintain, but your body is still in a physiologically steady state. This is the intensity at which elite marathoners run 26.2 miles. Right below their critical power. Severe IntensityPersonal anecdote: 10 Minute Assault BikeIn athlete language: "hard", "tough"What it feels like: breathing is heavy, you can't speakTypical duration: 2-40 minutesOnce you speed up past LT2, your body is no longer in a physiologically steady state. Your VO2 and lactate will continue to climb until you reach task failure, when you can no longer hold the pace (this is also the point that defines your VO2max and your maximum metabolite tolerance). Depending on the pace, task failure can happen in 3 minutes (as in a 1k row) or 40 minutes (as in a world class 10k row).Extreme IntensityPersonal anecdote: 30/30 RowIn athlete language: "full dummy", "blackout"What it feels like: numb or extreme discomfort during the work, then a painful lactate bath seconds to minutes after completionTypical duration: 2 minutes or lessFor an example of extreme intensity, check out ​this video​ from the 2020 Games. ---Every conditioning program is made up of some combination of exercise across these four intensity domains.They provide a framework for coaches and athletes to better understand physiology and their training. ---Link to join us at this year's training camp: https://paul-b-weber.kit.com/products/training-camp