What Do You Mean by Speed?

High-intensity training can boost your fitness but wield its power judiciously

By Joe Friel and Eric Schwartz
(This article originally appeared in Inside Triathlon)

How fast do you need to train to optimize your speed? The answer to that question varies depending upon whom you ask. Some people do several high-intensity sessions each week, and others do every workout at the same moderate pace. For a small minority of athletes one of these two plans may result in success, but the majority of multisport athletes' workout schedule should fall within these two extremes. There is no doubt that speed sessions will improve performance, but how fast and how often should you go hard?

High-intensity training can be defined as anaerobic, or above lactate threshold, workouts. Aerobic work is done at an effort below your lactate threshold. If you use a heart-rate monitor you can develop a good estimate of your lactate threshold (the training intensity at which you produce lactic acid more quickly than your body is able to flush it) by doing a hard 30-minute cycling or running time trial when you are rested. Determine your average heart rate over the last 20 minutes of the workout ¾ it will be close to your lactate-threshold heart rate. Note that you should perform tests on both the bike and run as your LT will differ for each sport.

Finding the balance

For most athletes, races under one hour will rely primarily on the anaerobic system ¾ that is, you will be racing above your LT. However, races longer than two hours are almost exclusively sub-LT efforts. Ironman-distance racing typically occurs substantially below lactate threshold.

Too much high-intensity training greatly increases the risk of illness, burnout and overtraining and such efforts require more recovery time as they temporarily break down the body. But with adequate rest the body will overcompensate and recover, leading to greater fitness.

The University of Colorado's Mark Whetmore, coach of one of the top U.S. collegiate running programs, warns against too much anaerobic training. Whetmore, who has coached U.S. Olympians Adam Goucher and Alan Culpepper, relies primarily on aerobic training and only adds anaerobic training toward the end of the season. Says Whetmore, “The contribution of anaerobic training to one's overall racing ability is overrated. It is more productive to train the aerobic system.”

Most athletes who are new to the sport and who have been sedentary for several years should avoid anaerobic work and focus on developing endurance and speed skills — the ability to work efficiently with minimal wasted movement and energy.

Following are guidelines for incorporating high-intensity workouts into your training ¾ taking into account the event for which you are training, whether sprint, Olympic or Ironman distance. High-intensity workouts should make up the bulk of your fast training but not the majority of your weekly training volume. And remember, novice athletes might be better off skipping high-intensity workouts while experienced athletes should develop a solid early-season base before including such sessions.

Going short: sprint-distance racing

Short, high-intensity workouts are most beneficial for this type of racing. Include short intervals of up to three minutes done at a few beats over lactate-threshold heart rate. The total time of high-intensity training within each workout should not exceed 15 minutes.

Workout 1. This can be done as a bike or run workout. After warming up, include a set of 4 x 3 minutes on, three minutes easy. Maintain a heart rate just above LT on the work intervals. Heart rate will take about a minute to correlate to effort, so rely on perceived effort at the beginning of each interval.

Workout 2. Much shorter intervals can also provide fitness improvements. For example, after warming up on the bike, go 3 x [60, 50, 40, 30, 20sec hard]. Each work interval should be performed at maximum effort. Take a minimum one-minute rest after each work interval and a five-minute recovery between each set.

Workout 3. A track workout with the main set consisting of 6-8 x 600 meters at 3-5 seconds per 400 meters faster than 5K race pace with a 300-meter jog recovery after each effort.

Workout 4. For your main set, swim 6 x 100 very fast on a 30-second recovery.

Structure these sessions into your training schedule in the two months leading up to your peak races, and do not perform more than three high-intensity workouts per week. Note that any workout in which you spend a considerable amount of time above your LT will require up to 48 hours (and perhaps even more) recovery time. Although recovery from swim workouts is quicker, too much high intensity in the pool can have a negative impact on the rest of your training.

Speed-endurance: Olympic-distance racing

Most triathletes can complete an Olympic-distance event in two to three and a half hours. When planning to race for this duration, there is still a premium on speed, but endurance takes on increased importance. Thus, the high-intensity workouts for Olympic-distance racing become longer and less intense, and since many athletes race near lactate threshold for the entire event, workouts at and just below lactate threshold are most effective. Each Olympic-distance speed workout should include between 20 and 40 minutes of intensity.

Workout 1. After a warm-up, include 2-3 x 10K on the bike, building up to lactate-threshold heart rate during each interval. Take a five-minute easy-spin recovery after each 10K work interval.

Workout 2. After a warm-up, bike or run 4-6 x 6 minutes. Maintain your heart rate between LT and eight beats below LT. Take a two-minute recovery after each work interval.

Workout 3. After a warm-up, run 20 minutes continuous at or just below lactate threshold.

Workout 4. For your main set, swim 6 x 100 at your 1000m time trial pace with 30-second recoveries.

Going long: half-IM to IM-distance training

Anaerobic workouts offer very little benefit for long-course racing. Instead, endurance is the primary limiter for most athletes. Incorporating some of the Olympic-distance high-intensity workouts will be useful, but most of the intensity training should be moderate and of longer duration. Half-Ironman preparation should include higher-intensity workouts than Ironman-distance.

Workout 1 . After warming up, ride 20-90 minutes at about 12 beats below lactate threshold. Earlier in the season, this work interval can be broken into shorter segments instead of one long effort (i.e. 3 x 20 minutes).

Workout 2. Warm-up, then run 20 minutes gradually uphill at about 12 beats below lactate threshold.

Workout 3. For your main set, swim 4 x 300, descending from a moderate/aerobic effort with a 30-second recovery after each work interval.

Be creative and you can create an unlimited number of workout variations from the guidelines above. Variation will keep it fun and consistency will lead to improved fitness.

Joe Friel is the author of The Triathlete's Training Bible . Eric Schwartz is an Ultrafit coach and competitive multisport athlete. You can contact Eric at eric@duathlon.com. Visit www.ultrafit.com for more information on training and racing.

In summary

High-intensity training can be defined as anaerobic, or above lactate threshold, workouts.

Novice athletes might be better off skipping high-intensity workouts while experienced athletes should develop a solid early-season base before including such sessions.

Structure these sessions into your training schedule in the two months leading up to your peak races, and do not perform more than three high-intensity workouts per week.