What Is Interval Training and How Do I Use it in My Workouts?
Interval training refers to taking a certain training distance or time period and dividing it up into smaller portions (i.e., intervals). Usually intervals are periods of higher intensity workouts with periods of lower intensity, or rest, interspersed in between. Because they are generally high intensity, intervals are not for de-conditioned or untrained people. Why is interval training important? Because it allows you to gradually build up the amount of time spent at higher intensities.
In order to understand the applications of interval training, it is important to first have an understanding of the bodys energy systems: aerobic and anaerobic. The aerobic energy system comes into play when exercise periods last more than 3 minutes. The anaerobic (lactic acid) system is involved for exercise that lasts 1-3 minutes, while the anaerobic (ATP/CP) energy system is involved for exercise that lasts less than 10 seconds. An example of aerobic exercise is skating at a moderate pace for 20 minutes (i.e. 60-70% maximum heart rate). If you boost up the intensity for a minute or two by chasing a bike or a faster skater, your muscles would quickly fatigue because they would build up lactic acid. This usually happens at or around the lactic acid threshold, also referred to as anaerobic threshold, or AT (point where the body switches from aerobic to anaerobic energy system), which is about 85% maximum heart rate for most people). This is the anaerobic lactic acid energy system. Finally, the anaerobic (ATP/PC) energy system is used for short bursts of energy, such as a quick short sprint, like at the start of a race. The body cannot maintain this intensity for more than 10 seconds, at which time it would switch over to one of the other energy systems.
Interval training usually focuses on improving the bodys utilization of the anaerobic energy systems. Therefore, intervals usually range from 1-3 minutes for the lactic acid system, which simulates real-life skating situations, such as catching and then passing someone on the trail or during a race, or an uphill section. Another example would be taking your turn leading a paceline in a race. Intervals can be very structured or they can be less structured and more playful. For example, you can skate hard (watching your heart rate monitor) from one reference point to another, such as from a post to the next post or from one intersection to another. Conversely, they can be more structured, such as 2 minutes of hard effort at a heart rate of 80-90% maximum and then 2-4 minutes recovery at a moderate heart rate between intervals. Beginners start easy and work up to 3-5 intervals per set and then add multiple sets. There should be significant recovery/active rest (keep moving, but at a significantly lower heart rate) between interval sets. You know that you are done when you cannot get your heart rate up to the same/similar level as the previous interval!
Because intervals are intense, they should not be done two days in a row. Most athletes start out with one interval workout a week and then progress to 2-3 times a week with days between intervals consisting of either complete rest, long-slow distance workouts, or shorter workouts. Remember that complete rest after an intense workout is very important for muscle recovery, especially for the older athlete or skater. This could mean taking one or two days completely off following a hard workout. It is also important to have variety in your workout routine, not just do the same intensity and distance every time you go out for a skate!
One dilemma for skaters is that as you become better conditioned, you have to keep skating faster and faster to get your heart rate up to anaerobic levels. Sometimes that is not feasible or practical, depending on skating ability or location. So, how do you get your interval workout in? I recommend incorporating hill training as part of your workouts. By skating up hills, you dont have to skate at breakneck speeds, but work hard enough to raise your heart rate adequately. The trick is coming back downhill safely! Choose a hill that is the right length for the duration of the interval, with the recovery being the ride back downhill. Another great way to get interval workouts in on skates is to join indoor speed-skating workouts at one of the local rinks that offers this (such as Lynnwood Roll-A-Way). This is also an incredible way to keep fit during the winter months!
What is the goal of interval training? The goal is to train your body to tolerate higher intensities. A well-trained athlete can skate at higher and higher heart rates and still be in the aerobic energy system (i.e. above 85 % maximum heart rate). Their bodies can also tolerate anaerobic exercise
better and longer than an untrained individual can.
Remember that following an intense workout, such as intervals, it is also important to refuel your body. For more information on this topic, see next months column, which will focus on sports nutrition.