Getting started with interval training

preface
Cardio is a swearword for many bodybuilders, at best a necessary evil during the competition diet. Others are convinced of the necessity (after all, the heart is also a muscle that needs to be trained), but can imagine more exciting things than performing monotonous movements for 60 minutes. Endurance athletes often cannot understand this negative attitude. This article is intended to provide food for thought to stimulate a varied design of endurance units. Due to their entertaining character, only interval-oriented trainings are presented in the article. In addition, the background of the units presented here in terms of sports science and training methods is deliberately dispensed with. The article is lust oriented. It should motivate you to try something new, to listen to your own body and to control the training intensity yourself. The aim is not to appeal to endurance athletes who want to reduce their 10 km best time to less than 40 minutes, but to hobby athletes who want to bring variety into their daily training routine. In principle, the methods presented here can be applied to all of the usual endurance sports. For the sake of simplicity, I will confine my remarks to running. If you prefer the bike, the rowing ergometer or a crosstrainer, the information must be adjusted accordingly.

Basic information
I know, I know. A lust oriented article and the author is bored with basics? Don't worry, the following section doesn't contain any theoretical gibberish. Rather, practical essentials are taught that are central to the design of a sustainable interval training. These are important not only to maximize the benefit of the units but also to prevent injuries due to the high load.

1.) The Around
The advantage of interval units is that they are short and crisp. The core of such a training session is often not longer than 20 minutes. For many an argument for intervals and against the supposedly lengthy "slow-and-steady" endurance units in the basic area. However, it should be noted that high-intensity intervals should always be preceded by an appropriate warm-up program! On the one hand, a well-designed warm-up makes top sporting performance possible. For example, it aims to improve blood circulation in the muscles, stimulate the cardiovascular system or achieve the optimum body temperature. On the other hand, it prevents injuries through precisely these processes. It also increases concentration psychologically and has a motivating effect at best. I don't want any general tips regarding. duration or structure of the warm-up, but in my personal experience it should be at least 10 minutes. If strength training has already taken place before the interval unit is completed (which I strongly advise against!), the duration can be reduced if necessary. Basically, an optimal warm-up consists of two components, the general and the specific warm-up. The former aims at the whole body and aims to increase the general level of activity. The intensity is loose. It is usually carried out in the same form in which the actual intervals are also carried out: those who run later begin with relaxed jogging. If you pedal later, you start cycling with little resistance. The general one is followed by the specific warm-up. It is intended to prepare certain muscle groups specifically for the impending strain. Hops running, for example, is suitable for activating hip flexors and trunk muscles. Runners will find a variety of possible exercises on Google under the keyword "Lauf-ABC".
Other options are plyometric exercises or a small selection of exercises with your own body weight that are aimed at the muscles that are subsequently stressed (e.g. squats, bulgarian split squats). I advise against stretching before the strain. The specific warm-up, and thus the entire warm-up program, is completed with short increases in the respective target sport. Runners do uphill runs in which they increase the running speed steadily over a short distance of about 100m from easy jogging to the sprint. Then the speed is slowly reduced again to the initial speed. After a short trot break the next repetition takes place. Three total repetitions are sufficient. A short, active rest period (trotting loosely) follows the increases. When the heart rate has calmed down again, the actual interval training ("Training" section) can begin.

Following the core of the unit, the implementation of a waste heat program is also highly recommended. The aim is to reduce body and mind and to start the regeneration phase. Lactate is broken down, the development of sore muscles is prevented and overall regeneration is improved. This active conclusion of the training is usually carried out in the form of loose (aerobic) endurance activity (e.g. trotting). 5-15 minutes is enough. I also explicitly advise against making the cool-down last longer than 15 minutes. After the intervals, one may feel that an additional 20-30 minutes can still be called up during a relaxed workout. However, one should resist this temptation (with which an increase of the total calorie consumption would go along) absolutely. Such a mixture of interval training and (subsequent) basic training disrupts regeneration and weakens the training effect of interval training. Trot out loosely and replenish your memory with quickly digestible carbohydrates is the motto!

2.) The intensity
The basic aim of the article is to provide food for thought for the design of training units. The adaptation of these suggestions to your level of performance should be done individually. The following section therefore deals with levers that can be used to regulate the intensity of interval training.

First there is the (distance) length or duration (time) of the fast section. Depending on the logistics framework conditions, it makes more sense to regulate using one or the other. For example, if you have a public stadium in the surrounding area, you can use your interval units there route-controlled. One lap length corresponds to 400m. Other fresh air athletes who do not have this option will rather divide their intervals into time periods. Cardio equipment in gyms usually offers both options: both distance and time are displayed.

The second set screw is the speed of the fast section. Depending on the length/duration and number of repetitions that are planned in total, you should adjust accordingly. It is important to keep in mind that a constant speed can be maintained in any case! In other words, the first interval should be as fast as the last. An often observed mistake is that athletes take over at the beginning and performance decreases too much towards the end. In addition, many athletes seem to have internalized the assumption that interval training should always be done at the limit of performance. This assumption is wrong. In principle, the shorter the individual interval sections, the more intensive the load. Nevertheless, the intervals should always be checked and executed in a technically clean manner, not completely at the stop.

Furthermore, the intensity can be adjusted by the number of repetitions. This form of regulation is particularly suitable for beginners in interval training. Instead of doing a series of 10 hill sprints, for example, you start with 6 clean ones. If the condition improves, you can first increase to 8 repetitions and later to 10. Here you should also be flexible and keep the option open to adapt self-defined goals during the unit and not carry out all repetitions if necessary. Important termination criteria are the technique and the speed of the intervals. Runners often notice towards the end of the session that they tear more with their arms and shoulders or adopt a curved posture to relieve the exhausted trunk and leg muscles. If the speed drops more and more compared to the first repetitions, this is a clear signal to initiate the waste heat program.

In addition to the intervals themselves, the breaks can of course also be designed individually. On the one hand, this happens over the duration of the breaks. In principle, the breaks should not last longer than the load. At short, intense intervals and many repetitions (what many nowadays call HIIT) I prefer a load to pause ratio of 2:1, so if you sprint for 1 minute, then take a 30s pause. Depending on the power level, however, the pause can be adjusted to a ratio of 1:1. If you control the load over the track, it makes sense to arrange the duration of the break over the track. For example, a 400m sprint could be followed by a 200m trot break. Since the speed during the break is naturally significantly lower than during the load, the time ratio of load to break will also be similar in the route-controlled procedure, as with the

3.) The Equipment
It doesn't really need a lot of equipment. Those who complete their intervals in the studio will usually find everything they need in the cardio equipment there (time and distance meters). However, due to the bulky handling of the devices, it is usually more convenient to use your own stopwatch. Some modern devices have a special interval function, which makes it possible to pre-program a unit specifically. It is also advisable to try different cardio machines: Especially at intervals, it is important that the intensity (i.e. speed or watts) can be regulated continuously and quickly. In my experience, there are enormous differences between the devices.

If you do your intervals in the open air, you should make sure that a run/stopwatch has a lap function when you buy it. So you can stop your lap times to control the duration of load and pause. Some watches also have a programmable interval function.

Optional is a heart rate monitor with chest strap for better training control. However, this requires a suitable performance diagnosis in order to know the individual training areas and their heart rates.

The Training
In the following different methods are to be represented, on the basis of which an interval training can be provided. The various approaches are not exhaustive and are merely intended to provide the reader with the tools to put together an individual training session.

1.) Time-controlled training
With this method, the intensity is regulated by the duration of the intervals and the pauses. Most HIIT protocols are based on this method and are characterized by short sections of load and pause. One example is the Tabata method, named after its Japanese inventor. First published in a study in 1996, this method contributed to the continuing trend of high-intensity interval training. At its core, it is based on a 20s long, highly intensive load, followed by a 10s break. This pattern is repeated for a total of 4 minutes (i.e. 8 cycles). However, the central factor for the effectiveness of the method is that the load is almost at the stop ("vomit limit").

Since this form of interval training is very demanding (also for regeneration) I would like to encourage the reader to try other protocols. An example would be 1-minute loads, followed by a break of 30 seconds each. The whole thing can be repeated 6-10 times, depending on the performance level. The 2:1 ratio of load to pause can also be adjusted to other interval lengths, e.g. 2 minutes load and 1 minute pause. It should be noted that the length of the loads is in inverse proportion to the total number of repetitions. In concrete terms, this means that the longer the stress, the fewer total repetitions have to be completed. From a length of 3-4 minutes per interval, more than 4-6 repetitions are not necessary.

Another time-controlled approach to interval training is pyramid training. The duration of the intervals is varied while the pause duration remains constant. An example would be the load sequence 1 min. - 3 min. - 5 min. - 3 min. - 1 min, interrupted by a break of 2 to 3 minutes each. The load duration is thus increased in the form of stairs and then reduced again in the same way. Depending on the duration of the intervals, the load is either intensive (short intervals) or extensive (longer intervals). The speed of the loads should be constant. A particular advantage of this form of training is that it trains the athlete's sense of speed: If the first intervals are already started too fast, the tempo in the longest interval of the pyramid (and afterwards) can hardly be maintained.

2.) Route-controlled training
If you are training on a cardio machine with a corresponding function, a track or a bicycle with a distance meter, you can also control the training on the basis of the track length. Here, the length of the loads and the length of the breaks are determined in advance. An example of a HIIT protocol based on the track length would be 8 cycles of 200m long sprints, followed by 100m trot break. If the emphasis in your training is less on improving the maximum oxygen capacity but rather on improving the general endurance, the interval duration should be correspondingly longer. For example 800m with 400m trot break each for 4-5 repetitions. Intervals longer than 800m are quite common among endurance athletes (e.g. 4x2000m), but not necessary for bodybuilders. Of course you can also do an interval training based on track length in the form of a pyramid (e.g. 200m-400m-600m-400m-200m with 200m trot break each). Advanced athletes stop the time they need for a stretch of track. On the one hand to include this parameter as an objective in the training planning (e.g. 8x400m load in 1:45 min. each). On the other hand, to monitor during the unit whether the tempo of the intervals remains constant (duration of first interval = duration of last interval?). In addition, the additional control of the interval time has the advantage that training progress can be better determined (the same distance can be covered continuously in a shorter time).

Another very effective, route-controlled training approach are hill sprints. The name says it all: a steep hill is sprinted up several times. The break consists of trotting down the same hill loosely. The intensity of the sprints is not only regulated by the speed, but also by the gradient of the hill (the steeper the more intensive). The same applies: the steeper the hill, the shorter the load should be. 1 to 2 minutes per load should be considered the upper limit. The number of total repetitions should be adapted to the individual performance level. Hill sprints are not only a challenge for the cardiovascular system, they also represent an excellent strength endurance training. Especially athletes who have never done this kind of training before will feel the different (muscular) strain at the latest the next day! It is important to ensure a clean technique and not to tear excessively with the shoulder/arm section. Furthermore I recommend to do hill sprints in the open air. The incline can be adjusted on many treadmills. However, this sometimes happens quite sluggishly. It is also not possible to trot downhill during the break.

A similarly sophisticated and effective method is stair sprinting. The functional principle is similar to that of the hill sprints: A staircase (or a section of stairs) is quickly sprinted up with clean technology (!). The break consists of trotting down the same stairs again. Climbing stairs consumes more calories per minute than normal jogging and is particularly demanding for the muscles of the buttocks, legs and trunk. Professional stair runners such as Matthias Jahn take two steps at once. Decide for yourself what is more pleasant for you. Athletes with knee problems should not use this training method.

3.) Heart rate controlled training
The ideal way to control your training is heart rate based. Ambitious endurance athletes usually use a combination of the methods already mentioned and combine them with a pulse measurement: they set a time limit (section 1.) in which they complete a certain distance (section 2.), whereby their heart rate must always be within a certain range. This should ensure both intensity and quality in terms of maximum training benefit. The problem with this approach is that the training areas are usually given as a percentage of the maximum heart rate and are not calculated from VO2max. An essential prerequisite for heart rate controlled training is also a performance diagnosis, on the basis of which the corresponding training areas can be calculated. A lactate measurement or a determination of the maximum heart rate in the self-test are not suitable for this (but more about this in a later article)! Moreover, this article is not aimed at ambitious endurance athletes either. Rather it is to motivate to arrange the training after the personal performance feeling and to train thus also the body perception. Therefore, the heart rate controlled training will not be discussed here in more detail.

4.) Other approaches
A purely intuitive approach to interval training is the driving game. The basis is a quiet to fast endurance run in which shorter, faster sections can be driven in as desired. Duration, intensity and number of intervals are not subject to any pre-defined rules. The design of the unit is playful during the training. In the early 1930s, the driving game was the preferred training method of top runners of that time. It is unjustly much less common nowadays. Driving games are entertaining, effective and better adaptable to the daily form than other, more rigid forms of training. A disadvantage, however, is that controlling the intensity of the strain requires some training experience. Therefore it makes sense to reflect during or after the unit: were the first intervals too fast? Did I take over or was I underchallenged?

One last method is final sprints. Several intervals are entered shortly before the end of a continuous run. The intensity can be controlled based on time or distance. Other athletes prefer warm up races, as already discussed in the "The Around" section on the topic of warm-up. An example of such a training session could be: 45min smooth endurance run, followed by five ascent runs of approx. 100m length.

Concluding remarks
The article should allow athletes beyond endurance sports a simple, pragmatic introduction to interval training. The basic building blocks (warm-up, intervals, cool-down) of an interval unit were presented without going too far into training science. Subsequently, various approaches for the design of interval trainings were discussed. It was consistently emphasized that the suggestions should be adapted to individual requirements and performance levels and not shy away from interrupting the intervals when technology or speed were decreasing and switching prematurely to cool-down.

If you decide to integrate interval training into your training plan, it is also advisable to make the sessions varied. To stay in the example from above: do not complete the same unit with 6x400m every week but also test yourself at longer or shorter distances. Or choose a completely different approach, e.g. hill sprints. Finally, intervals alone are not sufficient for a long-term increase in endurance. Slow, longer endurance runs are just as much a part of it as crisp endurance runs.