Building Powerful Children Through Interval (Weight) Training

This week our Lesson Plans feature a session focused on building explosive power endurance through a method of training called Interval Weight Training (IWT).


“Short-term intense interval training is highly effective in altering the ratio of lean body mass to fat without compromising muscle mass.” - Pat O’Shea


The method was developed by Pat O’Shea in the 1960s and includes intense interval work that combines explosive movement patterns with aerobic exercise. This style of training uses a large percentage of the body’s muscle mass and both fast and slow twitch fibres. It has been shown to have a major impact on developing explosive power and endurance simultaneously and is a great tool for optimising human performance for any sport, such as athletics or gymnastics, or simply to build healthy humans.

A typical IWT session has three phases: 

Phase 1: A circuit that combines an explosive lift or movement, such as one of the Olympic Lifts, with an intense period of aerobic exercise, then a rest, repeated three times.

For younger children, or where space or kit is restricted, barbell movements can be replaced with other explosive movements, such as with kettlebells and med balls, and external loads can be removed completely and replaced with explosive bodyweight movements such as broad jumps, high jumps or skips for height. Good movement mechanics is, of course, always a priority and any explosive movement should aim to reach triple extension (extension of the ankles, knees and hips) in every repetition to achieve maximum benefit. 

Phase 2: Similar to phase 1, but the explosive movement is replaced with a less technical strength movement, such as a squat.

Again the movement, load and volume can be varied to keep things interesting and to achieve different results. 

Phase 3: A supplementary circuit, combining multiple movement patterns, repeated three times with minimal rest. This is often a gymnastics (or bodyweight movement) focused workout, but could be adapted to include dumbbell or kettlebell accessory movements to suit your needs.

To get the most out of interval weight training workouts the idea is to give maximum effort to each round; earning your short rest period to allow the central nervous system (CNS) to recover!

The IWT system is designed so that there are endless combinations of movements, loads, time and rep ranges that can be varied to achieve results, whatever your age or ability. 

Adapting I(W)T For Children

Interval weight training has huge benefits for people of all ages, including children, when adapted appropriately. But the key to sustained progress for health and fitness, especially for children, is to keep exercise fun and varied. IWT therefore forms just one part of a wider syllabus at Kidz Impact, as we aim to expose children to a wide range of activities and training styles. A great deal of care goes in to making sure the workload of any workout is adaptable to suit the age and ability of every individual and the team of expert coaches always encourage children to demonstrate good movement mechanics before increasing load, volume or intensity (this should apply for training adults too!).

For the youngest children, or those working at lower intensity, external loads can be replaced with bodyweight movements following the principles of the IWT system. The rest periods in IWT workouts also provide a perfect opportunity to keep kids busy with other tasks, such as providing technical feedback, sharing knowledge on topics including nutrition, mindset, and safety, or setting fun challenges for the mind and body!


Join the Kidz Impact community today and gain access to fun, varied and adaptable lesson plans, coach education and a wealth of resources to help inspire your members to stay healthy, get active and build confidence!


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