A rider recently asked me how a time-crunched cyclist should approach base-building, the process of using low-intensity rides to strengthen the aerobic system before moving on to harder workouts. The benefits of a bigger aerobic base are twofold: You'll burn more fat and become better at processing lactate (a substance produced during hard exercise), so you'll be able to ride more comfortably at a faster pace.
Pro athletes typically build a base by spending a few months focusing on long, moderately paced rides, for at least 15 hours per week. But many amateur cyclists, who may have only an hour each day on the bike, can't effectively build an aerobic base this way because six to eight weekly hours of easy riding aren't enough to achieve the necessary adaptations. After about a month your body will be used to the workload, and you'll stop improving. Also, you don't necessarily need a giant aerobic base for shorter events such as cyclocross races or even hard-charging club rides.
More: How Many Miles Should I Log During Base-Building?
The solution: a series of eight-to 11-week "build periods," separated by four to six weeks of recovery. During the build blocks, you'll do four hard rides per week, with intervals that boost lactate threshold (basically, the hardest pace at which you can ride comfortably) and VO2 max (your aerobic capacity, or your body's maximum capacity to process oxygen). This allows you to achieve the necessary workload in eight hours or less, leaving you three days for recovery and the rest of your busy life.
Because fatigue accumulates over time, the recovery periods will let you recharge. This on/off structure differs from the traditional base-building method, but the result is similar: My athletes usually see performance increases as they progress through two or three build/recovery cycles in a year.
More: 3 Biggest Base-Building Mistakes
Build and Recover
If you're new to cycling or haven't trained in more than a year, do six weeks of low-to moderate-intensity riding before starting your first build. If you've been off the bike for only six to 12 months, start with three or four weeks of easy riding.
More: What's the Right Intensity for Base-Building?
Plan your builds around goal events, such as a crit series or century. You may shorten or lengthen the recovery periods by a week or two as needed.
Target endurance during recovery periods: Ride easy for two weeks, then spend six to eight hours a week on moderate-to-challenging efforts, including group outings, hills, and longer rides.
Find build-block workouts and sample schedules at Bicycling.com/buildandrecover.