dd8f1431_How_Heart_Rate_Zones_Work__Description
[Heart Rate Zone] Zone 5 Goals: Sustained Speed, Leg/Arm TurnoverEnergy System: Glycolytic, Phosphagenic 104-max% [Description] 
At this zone, your intensity now exceeds your lactate threshold and your body is relatively stressed in its ability to withstand high lactate levels and remove lactate. In Zone 5, lactic acid builds up quickly, so this intensity cannot be sustained for long periods, but is useful for sustained surges of up to around 5 minutes, as there is still some contribution from aerobic energy systems.Because muscle and joint impact and lactic acid levels become extremely high in this zone, this type of training requires longer recovery periods between both workouts and intervals, especially in beginner athletes. In addition to increasing an athlete’s speed, training at this intensity will improve neuromuscular recruitment, economy, efficiency and turnover, but high levels of training in this zone is another common cause of overtraining. Typically, the only work done in this zone is interval training and hill repeats.Good for 2-5 minute intervals with 1:1 to 1:3 work:rest ratios.
How Heart Rate Zones Work
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