Endurance training can be divided into four areas: Basic, Speed, Anaerobic and Endurance-Strength.
Basic endurance training is for improving aerobic capacity and impact tolerance. Such sessions occur at 60-75% maximal heart rate (or, Level 1), depending on the skier’s experience and level. At least one long basic endurance session should be included in your weekly schedule. Basic endurance training should increase gradually throughout the basic endurance period.
Speed sessions are slightly faster than basic endurance training (Level 3/4), and are accomplished in interval format. Heart-rate levels during speed training should be around 75-85% maximum heart rate. Interval sessions can total 21-60 minutes. Each interval can be between 7-12 minutes. During speed training, breathing is accelerated, but only during anaerobic endurance training does breathing rhythm peak. Developing speed is important when training for a marathon, since part of the marathon is actually skiing at speed training pace. Include 1 or 2 speed sessions in your weekly schedule, depending on the time of year.
Interval training is a good choice when you first start working on speed, since it’s easier to keep up a good pace during short repeats and exertion levels are not too high. As you progress, you can add even-paced sessions to your schedule. Cut back on speed training during transition and tapering, when you replace some of the hard sessions with actual racing.
Anaerobic endurance training is generally very hard interval work, aimed at maximizing racing performance and oxygen uptake capacity. To make sure lactic acid levels remain at a manageable level, ski at just below full speed, in other words at 90-95% maximum heart rate, or, Level 4. Each of these intervals typically last 4-6 minutes. Anaerobic endurance training increases as the calendar approaches ski-race season.
For a goal-oriented active skier, including anaerobic endurance training 2-3 times a month is advisable. When tapering, training includes anaerobic endurance and speed work, as well as basic endurance and recovery.
For an active skier, sprint training is fast-paced interval training at 90-100% maximum heart rate. Repeats last 30-90 seconds. Recover for around 5 minutes. Do sprint work during transition and tapering periods. Training frequency is at about 4 times/month.
Endurance-strength is considered another category of endurance training. This type of training is typically done on roller skis during a “specific-strength” workout. These workouts incorporate repetitions between 150-250 meters each along a gradual uphill. There are three main specific strength exercises; double-pole, core-only and single-stick. Double pole is regular double poling, core-only is when the body is propelled by the initial crunch of the arms and torso without a follow-through of the arms and the single-stick is when a skier executes diagonal-stride arms while keeping the legs stationary so that all of the work comes from the upper body. For each exercise there are between 5-12 repetitions, depending on the time of year.