Implementing High-Intensity Aerobic Energy System Conditioning for Field Sports PDF

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Dan Baker's article on how to implement aerobic training for field athletes...

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Implementing High-Intensity Aerobic Energy System Conditioning for Field Sports By Dan Baker

Introduction Field sports are sports such as soccer, rugby union and rugby league, Australian Rules football (AFL), Gaelic football and field hockey. They are characterized by a somewhat stopstart nature, varying movement speeds, multiple changes of direction and the execution of decisions and individual skills under conditions of game pressure and/or fatigue and in the case of some of those sports, the threat of imminent collisions. The nature of the movements in these sports requires the utilization, and therefore training, of all three energy systems (ATP-PC, Glycolitic/Lactic acid and Aerobic systems). However despite the often stop-start nature of these sports, which heralds an increase in anaerobic energy contributions (10), highintensity aerobic power and conditioning can be critical for success in field sports (4). The purpose of this article is to detail a number of methods to develop high intensity aerobic conditioning and describe the practical implementation and integration of these methods into the Preparation Period training for field sport athletes.

Recent applied research in aerobic training for field sports Much research is now focused on Maximal Aerobic Speed (MAS). Research shows that the amount of time spent at or above the 100% Maximal Aerobic Speed (MAS) appears to be the critical factor for improving aerobic power (5-15). It has been determined that performing a number of short intervals at > 100% MAS was a more effective method of building aerobic power than the more traditional Long Slow Distance (LSD) training (14) (i.e. going for long road runs etc) or than attempting to train only one interval continuously at 100% MAS (13). Specifically, an intensity of 120% MAS was determined to be the best single speed for short intervals that are followed by a short respite (passive rest) interval, based upon the fact that this intensity allowed the greatest supra-maximal training impulse (intensity x volume), in comparison to 90, 100, and 140% MAS (13). Especially intervals of 120% MAS for 15-30 seconds followed by an equal respite interval of passive rest and continuing on for 5-10 minutes. A Japanese researcher called Tabata (14) also found that athletes working at 170% VO2 Max (the % MAS was not reported) for 20 seconds followed by 10 seconds passive rest and continuing on this manner for 4-minutes produced excellent changes in aerobic and

anaerobic power, better than performing LSD training sessions of 60-minutes at 70% MAS. However, the high intensity group also improved 28% in anaerobic performance while the low intensity group was unchanged. Accordingly, given the greater results and less time investment, it was considered that the high intensity training was much more efficacious than LSD training. This type of training is typically now known as the Tabata method. The basis of all this recent research is that high intensity intervals of 15-30+ seconds, interspersed with 10-30 seconds of either low intensity active recovery (eg. < 40-70% MAS) or passive rest, continued in this manner for total set times of 4-10 minutes and repeated for 2 or more sets greatly enhances aerobic power and capacity. It didn’t matter much if it was 20 seconds work, 10 seconds recovery, 30:15, 15:15, the research has kept pointing to the fact that training at or above 100% MAS was the key intensity parameter and how long you spent there was the driving volume parameter under-pinning improvements in aerobic power. Consequently high-intensity interval training using intensities of 100% MAS to develop the ability to sustain high intensity efforts or intervals at 120%+ MAS to develop higher levels of MAS or enhance the ability to repeat high intensity efforts appear to be increasingly used in the training of field sport athletes (e.g. 1-15). The practical implementation of a number of these methods will be detailed below. But what about the polarity of aerobic training? Isn’t that how the endurance athletes are training? While true aerobic endurance athletes (e.g. distance runners, cyclists, triathletes etc) talk about the effectiveness of the polarity of training (using predominantly LSD < 85% MAS, with a portion, say 20%, of very high intensity training >92% MAS), it must be remembered that for field sport athletes, practical observation has shown that most of the skill and tactical training undertaken are at LSD type of speeds and heart rates. Thus, given that skill and tactical training with the sports coach is the major form of training performed by field sport athletes for most of the season and this training involves cardio-vascular stimulation at the lower end of the “polarity spectrum”, the role of the strength and conditioning coach is to provide a high-intensity stimulus to improve aerobic fitness. I will give you an example. When I worked in professional rugby league, over the last few years all the players wore GPS for every field training session and for games. We know that in games the players, depending upon their position and role, cover about 100-110 m/minute. This is similar in soccer but AFL football average about 125-145+ m/min because they are allowed over 100 substitutions per game, so they go hard and then get subbed off for a short respite before doing it again. But what distances do field sport athletes cover in skill/tactical sessions? Typically from my sport of NRL rugby league it is about 55-65 m/min (this is lower than soccer and AFL training sessions but in NRL the nature of the games are collisions etc). Typically performed skill and tactical training does not improve fitness but in its way it provides the polar opposite to the high intensity aerobic training I am about to discuss and it constitutes the vast majority of the training week for field sport athletes. Therefore when a strength & conditioning coach has access to the players for conditioning, they must utilize high-intensity methods, with

relative velocities of 140-160+m/min (this is inclusive of the rest periods, so for example 15sec at 5 m/s followed by 15/sec rest x 2 = 150 m/min). This then is the polarity of their training for field sport athletes – mostly the skill and tactical work is done at low intensity, so the specific conditioning must be done at high intensity.

Field testing of MAS – Measuring Maximal Aerobic Speed (MAS) There is some controversy about how to measure MAS for field sports (4). The MAS is physiologically defined as the lowest speed at which VO2 maximum (VO2 max) has occurred. In a laboratory this is measured with gas analysis while running on a treadmill, according to a number of accepted routines. However, some athletes can still run slightly faster than the first speed at which VO2 maximum has occurred without any change in VO2max ~ so there can be a slight difference in speeds at which VO2 max is occurring (but physiologically, the lowest speed at which VO2max occurred is the definition of MAS). This fact is one of the many confounding factors that sometimes cloud the issue of measuring MAS in athletes for the purpose of diagnosis and training prescription. Other simple ones include differences between treadmill running and running on a sports field! Nonetheless for field sports, MAS should be assessed during running based tests. Over the years a number of simple running-based field based tests have been developed that correlate with MAS measured via the treadmill/gas analysis method(s). Some field tests are continuous, some are intermittent, some are linear running, some are shuttle-based running, some are incremental and some are steady-paced. The most common field tests of MAS include the Montreal Beep test, the Multistage Shuttle Beep test, the YoYo IR1 test, time trials with set times (eg. 5-minutes or 6-minutes) or set distances that take the athletes between 5- to 7-minutes to complete (eg. 1200-m, 1500m, 2000-m). Some of these tests have been further modified, such as the Montreal test being altered to include 1-minute stages, rather than 2-minute stages and so on. The choice of tests and their merits sometimes cloud the issue of measuring MAS in athletes and the pro’s and cons of each method is not the scope of this article. In certain tests, the MAS is simply the speed attained in the final leg of the test eg. Montreal Beep test or YoYo IR1 test. However if the Multistage Shuttle Beep test is used, then this equation:

(MAS=1.34*MSST final speed – 2.86) must be used to correct for the fact that the constant decelerations involved with shuttling/change of directions reduces the true MAS (8). These tests give results expressed as km/hr, which will then need to be converted to m/s so that training distances can be easily calculated. For example, Level 12 Multistage Beep, = 14 km/hr * 1.34 = 18.86, minus 2.86 then equals 15.9 km/hr or 4.4m/s.

For a set-time trial MAS test, for example, a 5-min time running trial, determining the average speed is a simple process (eg. 1320 meters divided by 300 s = 4.4 m/s). The simple 5-minute time trial has been shown to correlate very highly (r = 0.94) with MAS (7). If using set distances, the time taken to complete the distance should be between 5- to 7minutes. For example, if an athlete ran 1400-m in 318-seconds, then the MAS would be 4.4 m/s. So once MAS is determined, it is very easy then to prescribe training. An example of a simple 5-minute field test for a theoretical soccer team with disparate MAS scores is outlined in Table 1. Training prescription for the following methods will then be illustrated using these theoretical scores. Table 1. Theoretical 5-minute time trial MAS test results for a group of soccer athletes. The athletes are assigned into four groups, based up their test results and their MAS is then used to the prescribe training that is described in the text, table and figures. Group 5-min MAS Time Trial 100% MAS 120% MAS 1 1420-1460 m 4.8 m/s 5.75 m/s 2 1360-1400 m 4.6 m/s 5.5 m/s 3 1300-1340 m 4.4 m/s 5.3 m/s 4 1240-1280 m 4.2 m/s 5.1 m/s

Different Methods of High-Intensity Training Outlined below are a number of different methods that may be applicable to the training of high-intensity aerobic training for field sport athletes. They are presented in the order that they should be presented to the athletes.

Long Intervals Long intervals (LI) of 60-seconds up to 5-minutes can provide a training impulse (volume x intensity) base before progressing to training of higher intensity. They are best used in the early Preparation period, because the underlying objective is to increase the volume of work performed at high intensity (> 92 % MAS) and as such may not integrate well with other training such as skill and tactical units. The lower the MAS score the athlete possesses, the more beneficial LI are as a training stimulus. Consequently, elite field sport athletes may spend less time (or even no time) performing LI as compared to developing or teenage athletes.

Typically these intervals would be completed at an intensity above critical speed (aka “anaerobic threshold” or about 85% MAS). The longer the interval, the lower the intensity, so 3-minutes @ 90-100% MAS may be a better upper limit of interval length. When performing multiple repetitions, it is very difficult to maintain a time limit of 66% of the interval best (ie. If an athlete can hold 100% MAS for 5-minutes in a one-off maximum effort test, they find it very difficult to perform multiple repetitions of 3-minute intervals at 100% MAS). For long intervals the work: recovery ratios are typically above 1:1 (eg. 3:2) or, at 1:1. If the ratios go much more than 3:1, then typically for LI, the % MAS is reduced, to say 120 MAS but alter the length of the intervals to 8:4, 12:6, 16:8 etc. One of the limitations of all the above conditioning methods is that there are predictable work periods. Athletes quickly adapt to some sort of pacing strategy or know when they are about to start their next effort. With this second Tabata method the coach can set different coloured cones for each time/distance interval for each group. Upon the “Go” command, the athletes start their effort but not till about 2-seconds after the start are they given the command which will designate which cone they run to and return from. They do not know until that point will they be running to the cone designating 6s out and back, 8s out and back, 16s out and back and so on (see Figure 5). This strategy disrupts running rhythm and recovery strategies, entails reaction to situational commands and causes repeat high-intensity efforts to occur at less predictable times more than any of the other above high-intensity methods.

Figure 5. A schematic example of the Modified Tabata protocol with variable interval lengths using only GROUP 4 in this schematic demonstration (Group 4’s 120% MAS equals 5m/s). Any interval length can be used, but a 2:1 ratio should be maintained. The athletes do not know which cone (Y= yellow cone, G = green cone, R = red cone etc) to run to until after each repetition has started. Set lengths are typically 4-minutes.

Periodization and progression of training across the Preparation Period The training methods above have an inbuilt intensity progression as athletes work from < 100% MAS in LI, to 100% MAS in the Grids method to 120 and 130% MAS in the EuroFit and Tabata methods. The other variable for difficulty progression is the choice between the active recovery (at < 40% in LI, to 60-70% MAS in the Grids method) versus the passive rest inherent in the EuroFit and Tabata methods. Furthermore the Tabata method’s work:rest ratio of 2:1 may prove even more difficult as compared to the 1:1 EuroFit method. The second Tabata method with variable interval lengths may prove more evenT difficult for athletes but this may be due to reasons other than just physiological reasons. Introducing turns in the Tabata, or any method, will also cause an increase in difficulty as this increases the anaerobic contribution (10). Training can be progressed via the systematic use of all of these different methods, starting with the 3-minute LI’s and reducing LI length to 60-s, then the 100%:70% grids method, moving to the EuroFit 120% MAS method and finishing with the Japanese Tabata methods within a training cycle. Each method can be implemented for 1-3 weeks before progressing to the next method or a weekly cycle can involve a number of methods (see Tables 1 and 2). Within each 2-3 week mini-cycle, the typical volume progressions would also occur (5minute sets building up to 8- or even 10-minute sets and/or 2 sets building up to 3 or 4 sets). Consequently when a progression to the new method occurs there is a marked decrease in volume, but an increase in intensity ~ this week serves as a “volume un-load” week (see weeks 4 & 7 in Table 2). Therefore as intensity initially increases with the introduction of the new method, volume is lowest, but builds up over time before implementing the next intensity progression, again with a lower volume. Once an athlete has attained some training experience with these methods, weekly undulating periodization is also possible with one aerobic training day emphasizing increasing the time spent at ~100% MAS (and possibly also the time of each repetition spent at 100% MAS) via the grids method and the other training day spent emphasizing the time spent well above 100% MAS (ie. The Eurofit or Tabata methods) (See Table 2, Day 1 versus Day 3). This methodology is based around the Supramax methods DEVELOPING new aerobic power and improving the ability to repeat high-intensity efforts and the Maximal method, conditioning the body to SUSTAIN the current 100% MAS for longer periods. This within-week alternation of methods allows the athlete to toggle between milder active recovery (eg. 15 s @ 70% MAS or 90-s @ 40% MAS) and passive recovery (15-s rest). An example of these progressions appropriate to the General Preparation phase is depicted in Table 2. If the GP phase is only 4-weeks long, then this might be modified such that LI, Grids, EuroFit and then Tabata methods are the predominant (but not only) drill for each week.

Table 2. An example of the progression and possible weekly variation of methods, appropriate to the General Preparation Phase. Day 1 – Volume Emphasis Day 2 – Mixed Emphasis Day 3 – Intensity Emphasis Long Interval – 2-min @ Test MAS – 5min time trial Long Intervals – 90-s @ 96% MAS:90-s Long Interval – 3-min @ 90% MAS:2-min 93% MAS:2-min @40% @ 40% x 5-reps x 2-sets. Week 1 x 5-reps x 2-sets. @40% x 4-reps x 2-sets. Rest 2-mins between sets. Rest 3-mins between sets. Rest 4-mins between sets. Long Intervals – 90-s @ Long Intervals – 3-min @ 92% MAS:2Grids 100%:70% x 15:15 x 98% MAS:90-s @ 40% x Week 2 min @40% x 5-reps x 2-sets. 5-mins x 4-sets. 5-reps x 2-sets. Rest 4-mins between sets. Rest 3-mins between sets. Rest 2-mins between sets. Long Intervals – 90-s @ Long Intervals – 3-min @ 94% MAS:2Grids 102%:70% x 15:15 x 6-mins x 3100% MAS:90-s @ 40% Week 3 min @40% x 5-reps x 2-sets. sets. x 5-reps x 3-sets. Rest 4-mins between sets. Rest 2-mins between sets. Rest 3-mins between sets. Retest MAS. Rest 5-mins, then: Grids 104%:70% x 15:15 EuroFit 120% MAS 15:15 Week 4 Long Interval – 60-s @ 100% MAS:60-s x 6-mins x 3-sets. x 12-reps (6-mins) x 2-sets. (Deload) @40% x 4-reps x 2-sets. Rest 3-mins between sets. Rest 3-mins between sets. Rest 2-mins between sets. Grids 104%:70% x 15:15 EuroFit x 1-set (7-mins) x 8-mins x 2-sets. Grids x 1-set (7-mins) Tabata x 120% MAS x 20:10 x 10-reps x Week 5 EuroFit 120% MAS 15:15 LI – 60-s:60-s x 4 (83-sets. x 14-reps (7-mins) x 2-sets. mins) Rest 3-mins between sets. Rest 3-mins between sets. Rest 3-mins between sets. Grids 105%:70% x 15:15 x 8-mins x 2Tabata x 120% MAS x Tabata 125% 20:10 x 10 x 1-set sets. 20:10 x 8-reps x 2-sets Unpredictable Tabata Week 6 EuroFit 125% MAS 15:15 EuroFit x 120% MAS x 5- to 6-min set x 2-sets. x 16-reps (8-mins) x 2-sets. 20:20 x 8-reps x 2-sets Rest 3-mins between sets. Rest 3-mins between sets. Rest 3-mins between sets. EuroFit x 120% MAS x 20:20 x 8-reps Tabata x 1 (5-mins) Grids 103%:70% x 15:15 x 8-mins x 2SSG x 1 (8-mins) SSG x 1 (5-mins) sets. Week 7 EuroFit x 120% MAS x Unpredictable Tabata (5-mins) EuroFit 125% MAS 15:15 SSG x 1 (5-mins) 20:20 x 8-reps x 16-reps (8-mins) x 2-sets. Rest 2-mins between sets. SSG x 1 (8-mins) Rest 2-mins between sets. Tetest MAS Week 8 End of General Preparation

Integrating high-intensity aerobic training with sports training and small-sided games (SSG) The limitation of the above methods is that there is still some ‘predictability” about them. Field sports often require intense efforts at unpredictable times and hence some researchers and coaches have advocated small sided games as a better alternative to traditional conditioning due to the “unpredictability” of games and the fact that games also develop

sports skills and game sense. However the overload delivered by games by themselves is also unpredictable and depends upon the structure and rules of the games etc. I have data from that shows the athletes with the highest MAS covered the most meters in each SSG and had the most winning outcomes, so how would SSG improve those athletes with lower MAS scores? My recommendation is that almost all athletes below the elite or professional level are better suited to using traditional conditioning methods as described above to develop greater MAS and fitness levels in the General Preparation phase, rather than relying on small sided games to develop aerobic fitness. So what role do SSG play? For the elite performer, with GPS technology to monitor running workloads in real-time, plenty of assistant coaches watching, high motivation levels etc, SSG are great. But athletes below that elite level? My experience has shown that conditioning-oriented SSG become more effective after the GP phase, once fitness levels have been established. Once a field sport athlete has attained an adequate MAS and is in the Specific Preparation phase or Competitive Periods of the sport season, then skill and tactical training must takes precedence. It is during the Specific Prep...