2.Warm-up:Warming up is part of the initial phase of any PE session. It prepares the body to make an effort, it improves perfomance and it helps to prevent possible injuries. 2.1Factors that must be considered: Age, The sport/activity, Personal level, The time of the day. 2.2Types of warm-ups: General warm-up, Specific warm-up, Preventive warm-up, Active warm-up. 2.3General characteristics: Between 10 and 20 minutes, The rhythm should be progressive, Adapted to the activity is going to follow, Done individually or in pairs, equipment can be used.2.4Phases of the warm-up: Slow run, Joint mobility exercises and dynamic stretching, General exercises, Specific excercises.3.Endurance: It is defined as the capacity that allows us maintain physical exercise for a prolonged time and recover quickly after doing a physical activity. 3.1Factors that determine the endurance:Volume of the effort, Intensity of the effort: MHR=220-age, Oxygen. 3.2Types of endurance: a)Aerobic stamina: High volume of effort, Low or moderate intensity, Enough oxygen reaches the muscles, Heart rate fluctuates between 120 and 160 per minute, Examples:5000 meters, 10000 meters or marathon in athletics. b)Anaerobic stamina: Low volume of effort, High intensity, Not enough oxygen reaches the muscles, Heart rate fluctuates between 170 and 190 per minute. Examples: 400 meters or 800 meters in athletics. 3.3Sports can be classified by the types of endurance: Aerobic sports, Anaerobic sports, Mixed sports. 4.Speed: It is defined as the ability to perform one or several movements at maximum intensity at the shortest time possible. 4.1Types of speed: Travel speed, Reaction speed, Movement speed. 5.Strenght: It is defined as the body's ability to beat or overcome resistance using the tension produced in muscles by the contraction of muscles fibres. Physics defines force as the result of mass multiplicated by acceleration. F=m x a 5.1Types of strength: Maximum strength, Explosive strength, Strength endurance. 6.Flexibility: It is defined as the maximum possible range of a joint during a movement. It has a huge influence on the ability to correctly execute technical moves in any sport. 6.1Types of flexibility: Functional flexibility, Residual flexibility, Absolute flexibility. 6.2 Other concepts: Dynamic stretching during your warm-up, Static stretching at the end of your training session, Your Range of Movement depends of your degree of flexibility, Joints, Elasticity is the body's ability to return to its resting position when there is no force acting on it.