The
very large increase in the number of rucks and tackles during the game (pre vs. post 1995) results ina greater impact stress for each player, resulting in varying degrees of muscle damage. the changing laws have resulted in an increased pace of the game, longer duration of activity, and greater amounts of physical contact requiring strength and power.
The game has also evolved to have an increased number of passes, tackles, rucks, tries and ball-in-play time. Overall, these changes have resulted in an increase in the pace of the game and also the amount of physical contact.
Activities during the games at the 1995 (pre-professionalism) and 2007 World Cup tournaments
Activities for the Bledisloe Cup matches played before 1995 (n = 17) compared to the matches played after the onset of professionalism (1995) (n = 9)
Activity cycles per match (rucks, mauls, passes and kicks) at the 2003 and 2007 Rugby World Cup tournaments
I think muscle endurance is one of the most important aspects as its dependent on the muscle being able to contract repetitively without developing fatigue.
Muscle strength is defined as the ability to produce force.
Muscle power is a function of the interaction between force of contraction and the speed of contraction, is associated with the explosiveness of the muscle.
Speed consists of a number of things all of which are independent qualities namely acceleration speed, maximum speed and speed-endurance.
Acceleration the ability to accelerate and cover short distances
Repeat sprint The ability to resist fatigue after repeated short-duration, high-intensity sprints is a fitness characteristic which is important for team sports such as soccer, rugby, football, basketball and netball, to name a few.
Motor co-ordination aka skill is the combined interaction of agility, balance, co-ordination, power, speed and reaction time. In short making decisions as quickly as possible and implementing it.
Flexibility represents the range of motion specific to a joint. Can be random or static
Cardiovascular fitness refers to the collective ability of the cardiovascular system to adjust to the physiological stress of exercise.
and lastly
Body composition which is defined by the proportions of fat, muscle and bone.