In the sample six-month periodization program we provided in March, we had you start off with a moderately difficult Maintenance 1 period to prep for the harder efforts ahead. Now we move into three months of intense stress and recovery, beginning with the four-week Overload 1 period detailed in the chart below.
This high-intensity training block is intentionally heavy on tough threshold work (which helps to push back the point at which lactate floods the muscle) and tougher VO2 intervals, which quickly stress the entire system and make you faster. Your threshold is the number from your March field test (outsideonline.com/fieldtest)an estimate of your upper limit for sustained aerobic performance. Your VO2 maxthe upper limit of your oxygen-delivery systemis roughly equal to the fastest pace you would be able to sustain for six minutes.