Rugby - Assessment of training needs

Team sports like rugby are classed as 'intermittent sprint sports' because, in the course of a match, players will alternate between sprinting, running, jogging, walking and standing. Rugby matches are like random interval workouts and include sport-specific activities such as rucking, mauling and scrummaging. These are game-specific tasks, and like sprinting, they are high-intensity activities. When rugby players perform these high-intensity activities, their anaerobic systems provide the required energy, while the aerobic system predominates during the low-intensity activities.

Energy Pathways

The phosphocreatine (PC) system will be the key energy source. This is the simplest and most rapid means of energy production, in which phosphate (donated by PC) and Adenosine Diphosphate (ADP) combine to make Adenosine Triphosphate (ATP). During the low-intensity periods, the aerobic system will replenish PC stores, ready for the next high-intensity effort. If the high-intensity periods are short, less than 10 seconds and recovery times between efforts are relatively long, 60 seconds or more.

However, PC stores can provide energy for only about 10 seconds of activity. So, suppose the high-intensity periods are of intermediate length. In that case, 10 to 45 seconds or the recovery times are relatively short, 20 to 40 seconds, then the glycolytic system of anaerobic energy production, involving the breakdown of carbohydrates within muscle cells to release energy, comes into play. Similarly, short periods of high-intensity work, interspersed with recovery times that are too brief for complete replenishment of PC stores, also bring the glycolytic system into play.

Demands of player position

We need to understand the vital physiological demands on the players to help them train for top performance. There are two interesting questions about rugby:

What is the ratio of high-intensity to low-intensity activity?
Does the work/rest ratio vary with a player's position?

Recent research in New Zealand analysed the time and motion of 29 top-class professional rugby union players during eight professional 'Super 12' matches in New Zealand.

Players were placed into one of four positional groups:

Front row forwards (props and locks, or numbers 1,3, 4 & 5)
Back row forwards (hooker, flankers and no 8, or numbers 2, 6, 7 & 8)
Inside backs (fly-half and centres, or numbers 10, 12 & 13)
Outside backs (wingers and full-back, or numbers 11, 14 & 15)

The hooker was placed in the back-row group as they have a roving role at lineouts and do not push as much in the scrum as other front-row forwards. The scrum-half position was not analysed. One or two players from each positional group were analysed during each match.

The researchers broke down player movements as follows:

low-intensity activity
- standing still, walking, jogging, side and backwards stepping
high-intensity activity
- running, sprinting, rucking, mauling, scrummaging and tackling

They then analysed the amount of time spent in each movement category and each activity's frequency and average time. The critical data is summarised in the table below.

	Front Row Forwards	Back Row Forwards	Inside Backs	Outside Backs
Average high-intensity efforts per match	128 secs	113 secs	51 secs	46 secs
Average duration of high-intensity effort	5 secs	5.2 secs	4.2 secs	5.2 secs
Average duration of low-intensity effort	35 secs	37 secs	88 secs	115 secs

As you can see, front and back row forwards complete many more high-intensity efforts per match than backs, with front-row forwards performing over three times more than outside backs. While the average duration of high-intensity efforts is similar, at around five seconds, across all four positional groups, the average rest periods for the forwards are significantly shorter. Since both sets of forwards only enjoy approximately 35 seconds of recovery, their PC stores will not be replenished. So the glycolytic energy system will be vital for maintaining the work rate required.

Backs, by contrast, get plenty of recovery time between high-intensity efforts, 88 to 115 seconds, which is easily enough time to replenish PC stores. The PC system will be most important for backs.

The researchers also found that the type of high-intensity activity varied between positional groups. Back row forwards and inside backs completed an average of 7 sprints per match and outside backs an average of 11. Of the different kinds of high-intensity training, front row forwards performed fewer sprints, while backs performed more high-intensity runs and sprints.

By contrast, forwards were involved in many more rucks, mauls and scrums than backs. Front row forwards, for example, were involved in an average of 75 rucks/mauls and back-row forwards in 57, while inside and outside backs were involved in only 11 and 7, respectively.

Conclusion

This data leads to the following conclusions about the differences between forwards and backs:

Forwards have to complete more high-intensity activity than backs, with shorter periods of low-intensity activity between them, which means the anaerobic glycolytic system is of prime importance for them
The type of high-intensity activity forwards perform, tends to be 'physical work', e.g. pushing
Backs perform less high-intensity activity than forwards, with sufficient rest between efforts for the PC system to predominate
Running and sprinting are the commonest high-intensity activities for backs

Interval training for anaerobic fitness

Forwards need to develop good anaerobic fitness, explicitly targeting the glycolytic system. The best way to train this system is through interval training, ensuring that work periods are sufficiently long, 20 to 40 seconds, and rest periods long enough to allow athletes to repeat the work but not recover completely, 40 to 90 seconds. For example:

10 x 200 metres fast running, with 60 seconds rest.

However, as forwards tend to perform more high-intensity 'physical work' than running, performing intervals on a rowing machine might be better. For example:

5 sets of 4 x 200 metres fast rowing with 30 seconds rest between repetitions and 2 minutes between sets

Even more specific to the demands of match play would be interval workouts that combine 'physical work' with running. Players could work in pairs to push or wrestle with each other and then run a fixed distance, with the combination of push/wrestle and run counting as one interval repetition. This would prepare players to work intensively and make appropriate transitions between upper body/trunk strength tasks and running. For example:

20 x 5 seconds of push/wrestle + 50 metres shuttle run, with 30 seconds rest between reps

This kind of workout would closely match both the energy system and physical task demands of forwards' match play.

Backs, by contrast, need high anaerobic power, targeting the PC energy system. Interval training is also a very effective route to PC fitness, but the work intensity must be higher and the rest periods longer than with intervals targeting the glycolytic energy system; 5 to 8-second repetitions and rest periods lasting a minimum of 60 seconds would be highly appropriate. For example:

10 x 50 metres sprints with 90 seconds recovery

For backs, this sprinting workout would be sport specific, reflecting the amount of high-intensity running they perform in matches.

Aerobic

Aerobic fitness is vital for both backs and forwards since the aerobic system will provide most of the energy for movement and replenishment of PC stores during all low-intensity activities. Forwards will also use their aerobic systems to provide energy for the longer high-intensity or shorter recovery periods, providing valuable backup for the anaerobic glycolytic system.

As far as aerobic endurance training is concerned, the rowing machine may still be the best activity choice for forwards, with running best for backs. A combination of continuous steady-state training and interval workouts would be a practical approach. For example:

20 minutes running or rowing at 75% of max heart rate, or 10 x 400 metres running with 60 seconds rest or 6 x 500 metres rowing with 2 minutes rest

More specific workouts could be developed by performing shuttle runs instead of straight runs at intervals to increase the agility running component for backs. Also, sessions incorporating circuit exercises to improve pushing and wrestling strength would be helpful for forward players.

Article Reference

The information on this page is adapted from Brandon (2003)^[1] with the kind permission of Electric Word plc.

References

BRANDON, R. (2003) How Rugby players should train to reflect the varying energy demands of their field positions. Peak Performance, 185, p. 4-6

Page Reference

If you quote information from this page in your work, then the reference for this page is:

MACKENZIE, B. (2003) Rugby - Assessment of Training Needs [WWW] Available from: https://www.brianmac.co.uk/rugby/trainingneeds.htm [Accessed