A new slant on an old training concept (aka clarifying the high-intensity interval training, aka HIITS)
As athletes (from newbie to seasoned) we hear continually about interval training and HIITS, but there is a nagging voice that takes us back to believing LSD or long, slow-distance training to become faster and more efficient. What is that voice?
Why do we stick to this LSD thing?
This concept comes from interpretation of work done by famed running coach Arthur Lydiard, who contended that the most important aspect of conditioning is volume. His LSD training concepts were revolutionary and insightful, and brought phenomenal success to many athletes he trained. We figured it was the answer to successful running (and probably cycling and swimming).
The truth? Lydiard believed in speed work. LSD was a misnomer. Phew.
Lydiard’s formula advocated not just high-volume training but high volume at speeds near maximum steady state. His work with runners found that daily runs of 90 minutes at 70 percent maximum HR will boost mitochondria 30 percent higher than equivalent time spent at an easier 50 percent effort.
In Lydiard’s words, most training should be conducted close to the highest speed that you can run without going anaerobic. He had his runners, even marathon runners, compete in a 100-meter dash in a local track meet. He calls it “the plodding zone” and believed in 100-mile training weeks, but only to build aerobic strength to prepare the body for race-pace work that followed.
Okay, here is the technical stuff: hang in there
Metabolically, high-volume training makes sense. There are two main sources of fuel for exercise: carbohydrates (glycogen) and fats. The energy supply from carbohydrate and fat is inversely related. High rates of carbohydrate use reduce combustion of fat. Carbohydrates are used preferentially at very high efforts or at low fitness levels when fat metabolism is underdeveloped.
Conversely, when you teach your body to rely on fat for fuel, your combustion of carbohydrates goes down, thus sparing carbohydrates. This benefits performance in endurance events. You become fatigued when you run too low on carbohydrates. We store only a very limited amount of carbohydrate in our bodies. Compare this with a relatively unlimited supply of fat. Even an athlete with only six percent body fat will have enough fat to fuel exercise lasting for many hours. When you use more fat, you generate more energy.
Avoid Fatigue but Embrace Progressive Training.
If you swim, run, or ride long in something below z1, you are not receiving training benefit, just a mild level of fatigue. This fatigue can affect not only this session but also successive training sessions. This is like negative active recovery (detraining effect), and it might be better to simply take a nap or go watch a good movie.
Judicious use of high-intensity workouts during early season will not damage or ruin your fitness and may help to maintain and increase aerobic capacity. This training can be equally effective as traditional endurance-based training in improving aerobic capacity.
For example, a recent study examined the effect of high-intensity interval sessions on fat and carbohydrate metabolism and lactate concentrations in cyclists who had been training two to three hours per day for years. They replaced some of their endurance miles with two weekly sessions of six to nine five-minute intervals with one minute of recovery between. After six weeks, the percentage of energy coming from fat during a one-hour trial had increased from 6 percent to 13 percent.
One more technical thing
Studies show intensity sprints improve subjects’ time to exhaustion. They improve muscle glycogen, another key determinant of aerobic endurance. HIIT efforts bring up your overall aerobic capacity, which makes you better at all intensities. Researchers have demonstrated that after a 12-week, six-day-per-week program of 45 minutes of running and cycling at a high intensity, fat combustion increased by 41 percent. This was accompanied by reduced reliance on carbohydrates.
Overall, improvement requires training all systems throughout the year–Endurance, speed-endurance, speed, hills, and sprints.
During base phase of building miles, it is the daily consistency of training over a period of weeks and months that will boost fat metabolism. Miles may make champions, but those miles should be carefully (and gradually) developed, monitored, and arranged to get the maximum effect.
Endurance training is kind of a misnomer: you can’t really compartmentalize it. It consists of endurance, technique, strength, and speed. You need to maintain good form, which tends to dissipate at slower speeds. The body learns at speed: it is forced to throw off any extraneous movements to battle the resistance.
Think frequency and repeatability for the greatest return on investment. Train hard enough to stress your system and tax yourself somewhat, and easy enough so you could repeat the workout tomorrow.
Training depends on the athlete in terms of fitness level, lifestyle, level of experience, and myriad other factors. Aerobic adaptations can be achieved in more than one way, and HIIT efforts can be incorporated even into training phases primarily emphasizing aerobic adaptations.
For experienced athletes, you may work for 70 to 75 percent of maximum heart rate (either measured or perceived). For those just launching their careers, this will be closer to 60 to 65 percent of maximum heart rate (a perceive exertion—how does this feel?).
It is not practical or even possible for most people with full-time jobs and families to build up mileage quickly. The amount of mileage you will be able to train depends on your lifestyle, physical capabilities, and prior training history. Less-experienced athletes may want to build up mileage over a period of many months or even years.
Long efforts may tax certain athletes mentally, and cause negative effects. So resort to short and hard.
- You’ll improve your aerobic capacity. As your cardiovascular fitness improves, you’ll be able to exercise longer or with more intensity. Imagine finishing your 60-minute run in 45 minutes.
- You’ll keep boredom at bay. Turning up your intensity in short intervals can add variety to your exercise routine.
You don’t need special equipment. You can simply modify your current routine.
INTERVAL TRAINING IN 10 WORDS OR LESS
Never get too far from speed.
Incorporate some high-intensity efforts into your aerobic training, and you will improve all your body’s systems and get more bang for the buck. It will save you time, and you will reach whatever ‘effort’ is right for you now.
Increase work time and decrease recovery overall
WU 10 (or longer if you are inserting into aerobic workout)
5 x 1 min at 60-80% effort
easy 2 or 3 min in between (active recovery for running better than passive)
Progress to longer work intervals and shorter rest intervals:
5 x 3 min; 4 by 4min 2min recovery
4 x 5min, 2:30 recovery
Use easy/fresh/good PRE (perceived rate of exertion) for speed
Make speed your friend!