Unlike other forms of football, rugby can be usefully viewed as a succession of prolonged physical engagements, either between individual players or between groups of players. Each of these engagements demands the exercise of substantial physical strength. While basic strength training should form the foundation for such engagements, there should also be a focus on developing explosive strength appropriate to the particular activity.

During the extended periods when players are physically contesting with their opposing counterparts they are continually subjected to loading substantially greater than their own body weight. And, because that added resistance is live, there is often the problem of overcoming not only inertia but also counter force triggered by an initiating movement

In modern rugby considerable attention is given to fitness and aerobic conditioning as well as basic weight training, but there is very limited focus on the development of activity-specific explosive strength. This is despite the fact that an ability to very rapidly generate force can yield a competitive advantage in each of the areas of physical engagement in rugby:

Scrum and maul In the scrum or maul situation it is very difficult to shunt the opposing pack backward unless there is synchronised explosive activity. If a pack begins to move forward slowly or if just one or a couple of players attempt to initiate a shove, they are unlikely to be able to overcome the inertia of the opposing pack's body mass. In addition, the attempted drive forward will almost certainly trigger an almost immediate counter-shove. On the other hand if a pack suddenly and explosively begins to drive forward as a synchronised, coordinated unit, they are likely to be able to generate momentum and place their opponents on the back foot.

The key elements are that each of the forwards possess basic strength and a capacity to rapidly generate force. However, it is essential that their movements be synchronized. If any of these elements of strength, explosiveness and synchronicity are lacking the attempt is likely to prove futile or even counterproductive.

Tackle In a tackle situation there is great advantage in forcing the opponent, whether ball-carrier or tackler, back from the line of engagement. In order to do this effectively, the action has to be both powerful and virtually instantaneous.

In addition, ball-carriers with explosive leg drive are often able to brush past attempted tackles, while tacklers with similar attributes can forcefully secure the ball-carrier and take him to ground.

Ruck At the breakdown of play following a tackle the ability to push back or "clean out" opposing players from the ruck offers opportunities to win the contest for the ball or at least put the opposing team in a disadvantageous situation. The only effective way to win the breakdown contest is to apply very considerable force in an explosive manner.

Lineout The outcome of the lineout contest is largely dependent on how high the jumper can ascend, but also on how rapidly he can reach that point. This requires not only a very good vertical leap by the jumper, but also the ability of his support players to forcefully elevate him. Both jumping and lifting require specific forms of explosive strength.

When forward packs are evenly matched in strength and technique, and defensive techniques are well-coordinated, a game of rugby can often become a war of attrition, with teams attempting to wear one another down over the course of the game. It is very difficult to maintain concentration and alertness throughout an 80-minute game, and a capacity for explosive action allows the exploitation of fatigue and inattention. It provides surprise and unpredictability, while limiting the possibility of appropriate reaction.

Strength training for rugby should always be grounded on a solid foundation of basic strength; but coaches who are seeking to gain a sustainable competitive edge would do well to incorporate a comprehensive program of activity-specific training for explosive strength.