Energy System

Phosphagen System, Glycolytic System and Oxidative System

During gameplay, female players will require a broad range of energy system contributions, with the level of contribution of each energy system depending on the movement level and game event. Understanding the energy systems and their roles in performance can assist coaches in designing effective conditioning programs.

1. Phosphagen System (ATP-PCr)

Role:

• Provides immediate energy for explosive movements. E.g. Dominant carry or jumping for a high catch.

Mechanism:

• The ATP-PCr system uses adenosine triphosphate (ATP) that is directly stored in the muscles to fuel the performance of the short, explosive movements.

Usage:

• Activities such as line breaks, tackling, short sprints, scrummaging and lifting in the lineouts.

Duration:

• 0-10 seconds of maximal effort.

2. Glycolytic System 

Role:

• Provides energy for repeated high-intensity efforts when rest intervals are incomplete.  E.g. Attacking or defensive plays with a large number of phases.

Mechanism:

• The Glycolytic system relies on the breakdown of glucose to generate ATP, with this reaction occurring without the presence of oxygen (anaerobic) and resulting in the formation of by-products such as lactate and hydrogen ions, which can contribute to fatigue and decreased performance.

Usage:

• Extended phases of play involving repeated tackles, rucks, mauls and/or sprints.

Duration:

• 10-120 seconds of maximal effort.

 

3. Oxidative System 

Role:

• Provides energy for prolonged low- to moderate-intensity activity and supports recovery between high-intensity bouts. E.g. Scrum half moving from one ruck to another or back three player covering the back field.

Mechanism:

• The Oxidative system relies on ATP being produced via oxidative phosphorylation, which is a process that occurs in the mitochondria and uses oxygen to break down carbohydrates and fats.

Usage:

• Jogging, walking and recovery between high-intensity phases of play.

Duration:

• Dominant energy source after two minutes of sustained effort.