Criterium Workout of the Week: Mid-season Zone 2

As we approach the mid-season you've probably been racing lots and can feel that race form coming on strong.  However, many riders have just about hit the point where they need to take their foot off the gas and get back to basics. That's right, it's time to spend some mid-season time in Zone 2.

Racing and race-specific training involves repeated maximal and high-intensity efforts. These efforts place a significant demand on the body's anaerobic energy system, which relies on stored energy sources like glycogen and creatine phosphate to produce energy quickly. While race/anaerobic fitness gained from high-intensity efforts is important, relying solely on high-intensity training neglects the aerobic fitness and it's benefits. Over-emphasizing anaerobic fitness can lead to early onset of fatigue and decreased performance.

To review, Zone 2 intensity is generally considered to be moderate, somewhere around 60-70% of their maximum heart rate or power output or around 55-75% of your functional threshold power (FTP).

The goal of mid-season Zone 2 training is to re-build and maintain the strong aerobic base you spent a lot of time and energy on over the off-season.

Some of the key benefits of Zone 2 training include:

1. Increased aerobic capacity: Training in Zone 2 can improve the body's ability to use oxygen efficiently, which can lead to an increase in aerobic capacity. This allows you to sustain exercise for longer periods of time without fatigue.
2. Improved fat metabolism: Zone 2 training encourages the body to use fat as a fuel source, which can help to spare glycogen stores and delay the onset of fatigue.
3. Increased mitochondrial density: Mitochondria are the organelles in cells responsible for producing energy in the form of ATP. Zone 2 training can increase the number and size of mitochondria in muscle cells, which can lead to improved energy production and utilization.
4. Improved ability to uptake lactate exercise: Lactate threshold is the point at which the body begins to produce more lactate than it can clear, leading to fatigue and decreased performance.

So after your first big block of racing, go ahead and decompress by doing a bunch of Zone 2 training.  In a few weeks, when many of your competitors are running on fumes, wondering how they're going to make it through nationals you'll be fresh and fit and ready for that next bump in form.