High Intensity Intervals vs Steady, State Aerobic Training – Which is Better?

Because I put a lot of emphasis on interval training, people sometimes get the idea that I'm against steady state training. This is not the case. With my programs, at least 75-80% of you time is spent in an aerobic power and heart rate zone. I put the focus on the interval workouts as those are what tend to jump your power which you can then go faster aerobically. My approach is backwards to the conventional approach in that I focus on building maximum sustainable power and then translate that into longer distances.

To go faster, longer you need to accomplish the following:

Increased cardiac output – The heart and lungs need to be able to process more oxygen. Working muscles need oxygen, so the more you can process the faster you will potentially be able to go.

Increase mitochondrial development in the working muscles – these are the little power plants in the muscle cells that convert food and fat into motion. The more mitochondria you have, the more energy the muscles can process. Limited energy through-put is often what limits endurance performance.

Increase capillarization of the working muscles – capillaries are the little blood vessels that carry blood to the working muscles. The more capacity you have, the more blood that can transported to the muscle. More blood means more oxygen and more waste products carried away with each heartbeat.

Muscular endurance – This is related to the above adaptations but is not just the legs. You need good muscular endurance in the prime mover and the support muscles. Strong legs do not mean much if your back gives out.

For those of you not sure of definitions, I'll describe them in a way that you can practically apply.

Aerobic pace – Aerobic mean with oxygen so aerobic pace is a pace that is hard enough that you are working but you are able to keep up with the oxygen demands. When you first start riding your heart rate and breathing will pick up. From the point when your breathing picks up and you feel like you are doing a moderate but noticeable work to 90% of your functional threshold power will be aerobic.

From a feel stand point aerobic riding will be a moderately hard pace that you can sustain for extended periods of time (1-4 hours). Breathing will increase and you'll break a sweat but your legs will not be burning.

Anaerobic – Anaerobic means without oxygen so this is an intensity level where you can not keep up with the oxygen demand. There is not a magical point that the body switches from the aerobic energy system to anaerobic. It's a sliding scale. For the sake of our discussion Anaerobic pace is any level that is to hard to sustain for extended periods and is marked by the sensation of seeming to get harder at the same work level. Because you body is not getting enough oxygen you build a debt that leads to very heavy breathing and lots of burn.

Intervals – This is any workout that alternates periods of hard work with recovery. A graph of power output will look like a mountain range with spikes during the on phase and valleys during the recovery phase.

Most longer, steady training is predominately aerobic while intervals are crossing the line into heavy anaerobic statements.

Now here is where it can get complicated. Relatively short intervals (30 seconds) without enough recovery between them put a high load on the aerobic system as oxygen debt builds. The same holds true for short time trial efforts such as our fitness test, where you cover as much distance as possible in 8 minutes. That duration is too long for it to be totally anaerobic but the intensity level is too high for it to be purely aerobic. This type of work will overload both systems. The same holds true for Tabata intervals, Velmax intervals and 4X4s. Because these intervals hit both systems you get more bang for your training buck.

While you get a lot of progress out of doing interviews, your long distance ability will be compromised if this is the only thing you do. There needs to be a balance between longer steady state efforts and high intensity interval training. The longer your event, the more of your overall training time will be taken up with long steady efforts. Long steady rides will build capacity in the slow twitch endurance muscle fibers and improve your bodies ability to use fat as a fuel source. This last part is one of the big secrets of improving endurance. The training and nutrition you can get your body using a larger percentage of calories from stored body fat during long events, saving carbohydrates for the hard efforts that will come at the end of the race.

One of the big things I notice with athletes is that it is hard for them to dial it back to go easy enough for their aerobic training to be effective. It's not that a slightly higher pace does not give you training benefits, but a long ride that has repeated hard efforts (ie hills) or nudges up near your functional threshold power (max 60 min power) for sustained periods will take you longer to recover from. A moderate aerobic workout will take 8-12 hours to recover from but when you do it at a higher intensity it can take 48 hours or longer, decreasing the quality of your following workouts as you will not be recovered.

Here the benefits of each type of training:

High Intensity Intervals

Big effort yields big improvements – You have to go faster if you want to go faster. Intervals let you go faster in small doses which in time, leads to going faster for longer periods.

Great for fat burning – Intervals kick up your metabolism leaving it elevated for hours after training. This phenomenon can be used to ramp up your fat loss progress.

Hit muscle fibers that aerobic training does not – Fast twitch fibers get trained with explosive, hard efforts. You need them for sprints, hard accelerations and hill climbing.

Time efficient – You can overload both the aerobic and anaerobic system within one relatively short workout.

Variety – There are interviews to target improving just about anything. Increase threshold power, improve hill climbing power, increase you recovery ability between hard efforts, improve lactic acid tolerance, improve muscular endurance, sprint faster.

Interesting – This is particularly important in the winter. You have to pay attention when doing interviews so the time seems to go faster. Combined with the fact that the workouts are shorter means you are more likely to do them over the winter. While you need longer aerobic riding, intervals are the best thing to do in the off season if you can not bring yourself to put in 60+ minutes steady on the trainer.

Long, Steady Aerobic Riding

Improves capacity of the Slow Twitch (endurance) muscle fibers – Unless you are on the track, most of your cycling energy is going to be developed aerobically. If you are riding for 2 hours or more, most of your energy has to come from the aerobic system. It's just a fact. So improving the capacity of the aerobic muscle fibers will help you go faster for a longer period of time.

Improve your fuel economy – Long, steady rides improve your bodies ability to tap into stored body fat as a fuel source. This effect is not targeted at weight loss but improving your endurance by cutting down on the amount of carbohydrates your muscles need to go a given speed.

Improve recovery – Aerobic training, when done correctly (ie. Not too hard) is great to do between your hard workouts as you will get a training benefit but will not take days to recover from.

As you can see if you race or do long rides, if you want to do them fast you have to use both types of training to maximize your progress. You can get in very good shape doing just intervals but to go long you need to go long.

By Winston Endall

Source by Winston Endall