Though we have specific biological adaptations for running that other species do not have, training for performance has a relatively short history, both in practice and in scientific theory. Training practices like fartlek (speed play), invented by Gosta Holmer, and interval training, attributed to Waldemer Gerschler, were created in the 1920s, but it was not until the 1960s that research confirmed that manipulation of work duration, intensity and rest had a dramatic physiological response on performance (Astrand et al., 1960; Christensen et al., 1960). Training for performance to some degree is “trial and error”, or a learning experience; however, runners adopt training practices that offer performance results without treating the runner as a whole (the “magic bullet” approach) or incorporate training without knowing how to perform the workout effectively. I see this as problematic (see training philosophy) and hope to demystify "high" and "low" intensity training practices so that runners can train more meaningfully.
Recently, there has been a shift to "ditching the mileage" for higher intensity workouts, the argument being that higher intensity is "better than" lower intensity training because it can increase performance by 3 to 6%. On the one hand, many studies have confirmed the effectiveness of high-intensity training and have shown the physiological and performance impact of these methods - maximal oxygen consumption, running speed at lactate threshold, and running speed at peak oxygen consumption have shown a significant improvement in performance. But on the other, there is also a body of research evidence with elite runners showing that 60 to 85% of training is done at a low to moderate intensity. Despite this research, there is no scientifically valid training program because performance is a complex adaptation to training, which is not always a linear process. The question remains, which type of training is most effective?
The question "is high intensity training better than low intensity" will be addressed in three parts, starting with how to do intensity training effectively, followed by a discussion on how to do low intensity training effectively, and the last piece will discuss training load, which is the product of intensity, duration and frequency, and focus on basic training principles. The goal of all three pieces is to identify optimal training methods so that you can build your performance training program, and become a better runner.
part one of three: GO HARD OR GO HOME?
A commonly accepted definition of interval training is “repeated bouts of exercise lasting ~1 to 8 minutes and eliciting an oxygen demand equal to `90 to 100 % of VO2max separated by rest periods of 1 to 5 minutes(Seiler and Hetlelid, 2005).
Many runners think that in order to run fast, you must run faster. Training intensity varies minimally between workouts, from a steady run to LSD to tempo to interval, many adopt the "one zone" approach, and hope that over time, they will get faster. In running, practice does not always make perfect when it comes to getting faster (this will be explained in Part Three). When I coach, I review training data and ask that runners use their heart rate monitors. I have found that most of their training is done at a relatively high intensity of their maximum heart rate (MHR). I ask, "why are you always running so hard?", the response I get is commonly "to get faster!", which follows with another question "are you getting faster?". Unfortunately, the answer is not always "yes". Interval training can increase your performance, so the answer to "do I even need to do them?" is YES, if you have a performance or time-based goal.
When should high intensity intervals be incorporated into your training program? How long should the work efforts be? How long should the recovery last in between each effort?
The Workout 4 x 5 minutes @ 3-5km race effort with 1 minute rest
The complete workout is relatively short, only 35 minutes in duration, and performed once a week at the end of a training program. This workout was performed in week 6 of a 10-week structured training program.
The aim of this workout is to do 5 minutes at >90% of VO2max, and there was minimal rest between each set, making the workout short but very difficult. The purpose is to increase your maximum performance and speed, to tone the nervous system of your muscles, and to improve your maximal oxygen uptake (VO2max) and running efficiency. Always warm-up and cool-down for this session.
Merely performing intervals of increased effort is not enough, the key is to target a specific intensity (heart rate) to reap the rewards of this type of training. As the workout progresses, the accumulated workload increases (if you look at my data, my heart rate and pace increased each interval). Try to work progressively harder each interval: don't go out too hard and get progressively slower because of undue fatigue. Match the effort not the pace! Therefore, heart rate data is essential information for confirming the correct INTENSITY during an interval, not pace.
If you are doing this type of training session for the first time, you will be quickly introduced to the range of human emotions from pain and fatigue to pleasure and joy all at the same time! Most of us intuitively know our bodies, and with proper description of the purpose, we can match our intensity appropriately. Here is Chris's description of his first interval training session:
During the warm-up run I felt good with lots of energy, and I was looking forward to the session. This was the first time I had ever done an interval run. At the start of the first interval I realized my pace was a bit too fast and then I took it down a notch after the first minute. About ½ way through the 2nd interval I started to feel bad side-ache and had to slow down. For the 3rd and 4th intervals I was trying to keep the pace while holding my side; not a good feeling. Felt okay for the cool down and ran a bit slower than I normally do for cooling down. Side-ache was gone.
What did I learn?
1-The HR Graph doesn’t lie; it matches how I felt for the run. It spiked to 200+ early when I was going too fast, and it ranged 170-180 when I pulled back and was fighting the side-ache. 2-Don’t get too excited and go too fast at the beginning. Pace myself. 3-Don’t eat too close to a run. That BBQ pork chop was giving me the bad side-ache. Not a good feeling.
Chris was a little worried about this workout, as many others in the group were too because they were unsure if they could do it! Chris executed this workout perfectly! Interval training is individual to your body, and based on intensity not pace; all of us can perform at 85 to 95% of our heart rate max, so you don't have to be a sub-40 minute 10k runner to train with intervals (in other words, speed does not matter)!
tips on interval training
1. The duration of an interval should be 1 to 8 minutes. If you are new to interval training, try fartleks (speed plays) of 1 to 2 minutes fast with equal rest between to build your tolerance to high-intensity training.