By: Justin Freeman Saab Salomon Factory Team Level five, which I wrote about in my last article, is about improving race performance by working at a higher pace. Level three, which improves racing by working at a lower pace, is the natural complement to this training. Physiologically, the major goal of level three training is to improve lactate threshold. Your lactate threshold is the point at which lactic acid starts rapidly accumulating in your muscles. If you can do a treadmill test and plot speed versus lactate, your threshold is the point where the curve suddenly becomes steeper – the graph’s inflection point. Improvement in lactate threshold can take several forms. You can increase the speed at which lactic acid starts to build, or you can increase the heart rate at which lactic acid starts to build. These improvements could either increase or decrease the concentration of lactic acid in your blood at the inflect...