Let’s get back to interval training. I apologize for the long delay in posting Part 5. August has been quite busy with my annual bike tour in the Colorado mountains, selling our home in Boulder, and moving into new digs. Things are starting to settle down now, so I’m back at work.
In Part 4 I explained the terminology and commonly accepted methodology of intervals. Here’s a quick review.
Work Interval (WI). The high-intensity portions f the workout. The critical components here are WI duration and intensity. Typically, as the intensity of the WI increases its duration decreases. For sports such as running and cycling terrain is also a variable. They may be done on a flat surface or hills of varying grades. Corners may also be included, especially for cyclists preparing for criterium-style racing. Other variables are cadence (cycling), stroke (swimming), and equipment (running and cycling).
Recovery Interval (RI). The low-intensity, rest periods between the WI. Critical here are also intensity and duration. Generally as the intensity of the WI increases the intensity of the RI decreases with the reverse also being common. Long, relatively low-intensity WI are followed by short RI, as with aerobic endurance intervals explained in Part 4. In this case the ratio of WI to RI was about 4:1, meaning a long WI (20 minutes in the example) with a short RI (5 minutes in example). As you also read in the muscular force and speed skills intervals the WI duration can be quite long. A general rule is that when working on developing the cardiovascular/aerobic endurance system RI are kept short. When working on the nervous and muscular systems the RI are long. Also, over the course of several weeks of doing a particular type of interval workout it’s common for the RI to either get shorter or become slightly more intense. The reason for this is to more closely simulate the stresses of the race for which you are preparing where there are unlikely to be low-intensity, long-duration recoveries between hard efforts.
Work Interval Volume (WIV). This is the combined time of the WI within a single workout. As the intensity of the WI increases the WIV of the session decreases. The reason for this is to lower the risk of developing extreme fatigue, burnout, or injury. The sport you are training in also affects this. For example, of the three triathlon sports the one in which you are most likely to produce extreme fatigue, burnout, or injury is running. So the WIV of run intervals is usually much lower than that of swimming where the risk is considerably lower. Cycling fits between these two extremes. Your levels of fitness and experience in the sport are also critical to WIV. As these increase so does WIV.
Also in Part 4 I described the Training Triad I use in my system of training athletes. I’ve included that figure again here for reference. You may recall that in Part 4 I explained that the abilities at the corners of the Triad (aerobic endurance, muscular force, and speed skills) are the “basic” abilities. Those on the sides (muscular endurance, anaerobic endurance, and sprint power) are the “advanced” abilities. The basic abilities are most generally trained in the base period and the advanced abilities in the build period. this is not always the case. for ultra-distance events (such as Ironman, ultramarathons, etc) the advanced abilities may be developed in the late base period with aerobic endurance making up a large part of the build period.
Whenever I periodize an athlete’s season or write a weekly training plan I use this figure and these 6 abilities to help me make decisions. It’s a simple concept that I learned from Dr. Tudor Bompa.
There are other training methodologies that may work just as well for you if not better. There is not just one way to train. The key here is to keep all of the components of your personal training system cohesive and coordinated. Mixing various systems usually creates confusion and unfocused training. I frequently get questions from athletes wanting to know how they can use, for example, the heart rate zones they adopted from someone else in my workouts. I usually tell them to also use the other person’s total training system or forget the alternative zones and use mine.
Back to the topic at hand… Here are examples of interval workouts for the 6 advanced abilities.
Muscular endurance is the most basic of the advanced abilities. This is the type of workout that prepares the athlete for a steady, long race effort as when in a running race or bike time trial. For the road-racing cyclist such interval sessions pay off when riding in a fast moving peloton or steady climbing. ME training involves long work intervals (6-12 minutes) at or slightly below anaerobic threshold (or lactate threshold or functional threshold) with short RI (about 1/4th of the WI). So the work interval would be zone 4 (Coggan’s power or my heart rate zones). Depending on the sport, as explained above, an athlete should be able to do a WIV of about 20-60 minutes in a single session. This may be done once or twice a week. The workout would be something such as this:
WI duration: 6-12 minutes.
WI intensity: Coggan’s power or my pace, heart rate or perceived exertion zone 4
RI duration: 90 seconds to 3 minutes (about 4:1, WI:RI).
RI intensity: Zone 1 power, pace, heart rate, or perceived exertion (may increase to zone 2 over time).
WIV: 20-60 minutes.
Anaerobic endurance intervals have been shown to boost aerobic capacity (VO2max), economy, and anaerobic threshold [Billat, Laursen, Esfarjani]. This also is what often determines the outcome of a bicycle road race by preparing the rider for surges on hills, creating breaks, bridging to breaks, and racing in the wind when guttered. It is often done with work intervals that are 2-4 minutes long and done at or about aerobic capacity which is well above anaerobic threshold (Coggan’s power zone 5 or my effort or pace zone 5b). This is an intensity a well-trained athlete can only hold for about 5-6 minutes. If you can maintain the WI intensity for more than 5-6 minutes then the intensity is too low. RI are about of equal duration to the work intervals and a very low intensity, usually zone 1. I generally have athletes, depending on their sport, fitness, and experience level do 12-30 minutes of WIV of this type in a single session, once a week.
WI duration: 2-4 minutes. Runners often do these intervals on a track using a prescribed distance instead of time (for example, 800 meters). 30-second WI have also been shown to be quite effective when done with 30-second RI [Billat].
WI intensity: Any of the following: Coggan’s power zone 5 or my pace or perceived exertion zone 5b; VO2max pace or power; or CP5 or CP6 power or pace. Heart rate is not very useful for this workout as it is too slow to respond. The WI may be done on a hill to simulate race terrain.
RI duration: 2-4 minutes (or about 1:1, WI:RI). May be shortened with increasing fitness.
RI intensity: Zone 1 power, pace, heart rate, or perceived exertion (may increase to zone 2 over time).
WIV: 12-30 minutes.
Sprint power interval workouts are primarily used in non-steady state events in which the outcomes are determined by brief, maximal efforts. So this type of interval session falls primarily into the domain of road cyclists. Endurance runners and triathletes generally have no need for this training. One such workout is to do brief, all-out-effort sprints on varying terrain, straight-aways, and out of corners. Recovery lasts for several minutes after each sprint in order to allow subsequent intervals to be done at maximal intensity. Fatigue negates the benefits of this session. So when intensity drops by about 5% the session must end. Continuing will produce no greater benefits and may well lead to injury, deep fatigue, and burnout.
WI duration: 6-12 seconds. I often have cyclists do these intervals by counting 8-16 pedal revolutions (counting one leg only). The final, maximal portion of a finish line sprint is seldom longer than about 12 pedal revolutions.
WI intensity: Maximal effort. Heart rate is of no value in such a workout.
RI duration: 3-5 minutes.
RI intensity: A very low effort. Nearly total recovery is critical to this workout.
WIV: Stop the workout when power drops by 5%.
This ends my series on interval training. I hope you picked up something that will benefit your training. And, as always, I look forward to reading your comments.
References
Billat, V.L., et al. 1999. Interval training at VO2max: Effects on aerobic performance and overtraining markers. Med Sci Sports Exerc 31(1):156-63.
Laursen, P.B., et al. 2002. Interval training program optimization in highly trained endurance cyclists. Med Sci Sports Exerc 34(11):1801-7.
Esfarjani, F. and P.B. Laursen. 2007. Manipulating high-intensity interval training: Effects on VO2max, the lactate threshold and 3000m running performance in moderately trained males. J Sci Med Sport 10(1):27-35.
