In a previous column, I told you about the body's energy systems and in particular, lactate threshold. If you are looking to improve your speed at any race distance, you want to increase your lactate threshold.
If you take a snapshot of your fitness at any given time, your body can produce a particular pace for a given energy cost, or intensity. Think of this as your speed spectrum, with lactate threshold as one limit. At this limit, if you are conditioned, you have some 60 to 90 minutes of top threshold speed.
If you are a relatively new athlete that has not yet reached your metabolic limits, you can use threshold workouts to move lactate threshold to a greater percentage of VO2 max; thereby improving the metabolic limit as well as speed at threshold. Experienced athletes that are already near their metabolic limit for improving lactate threshold use threshold workouts to improve speed at threshold.
In this column, I'd like to share a few of my favorite bike threshold workouts. Though the workouts can be strategically used in a number of training plans, they are particularly useful for Olympic distance triathletes and cyclists aiming to improve their 40k time trial ability.
For all the workouts listed below, be sure to include a good warm-up of at least 20 to 30 minutes and a cool down of at least 15 minutes.
On a mostly flat course or indoor trainer, do 5-7 x 3 minutes, allowing heart rate to rise into Zones 4 to 5a over the course of the interval. Take 1 minute of easy spinning in Zone 1 between work intervals to recover. For the work intervals, begin the first one at the low end Zone 4 and end your last interval at the high end of Zone 5a. This strategy keeps your average power output and speed high for the entire session.