Fitness instructing: The 5 types of Strength
In this week’s blog for those interested in the fitness industry, we are looking at different types of strength.
The five components of fitness
Personal trainers will be aware that fitness is assessed based on five specific components: flexibility, muscular strength, muscular endurance, cardio-vascular fitness and motor skills.
To benefit from all-round physical fitness, you need a good balance of all five components. For fully rounded health and wellbeing, you will also need to consider factors such as nutrition, emotional and spiritual wellbeing, and medical and mental health.
Cardio-vascular v weight training
Within a gym environment, a personal trainer will often come across a client who runs every day but neglects their strength training. Alternatively, there are those who don’t do any cardio-vascular work but focus entirely on weight training, often working the same muscles every day.
Neither is a good example of well-rounded physical fitness. The runner is neglecting their physical strength, which will impact on their joints and cartilages as well as their performance, especially for hill running. Those who only train their chest muscles and biceps will have poor flexibility and cardio-vascular capabilities, and the lack of balance in their physique will be detrimental to their posture, making them more prone to injuries.
A good personal trainer will promote a well-rounded, balanced fitness programme, while taking into consideration the aims of their client.
Within weight training, there are five types of strength:
Maximal strength is the amount of force that can be generated in an all-out effort, regardless of the time someone takes to lift a weight. If two people of average fitness both weigh 13 stone, the one who can lift the heaviest weight in one rep has the highest maximal strength.
Maximal strength can be measured concentrically, eccentrically and isometrically, and genetics play a part. A personal trainer may have a client who is otherwise fit and healthy, but not genetically designed for maximal output.
Absolute strength is similar to maximal strength however the results are presented as a score or rating rather than a weight. A common exampe of this is a grip dynamometers to measure forearm grip strength.
Explosive strength is how far you can move a given weight in a unit of time. Also known as speed strength, it’s essentially about power. If a fitness instructor has two clients both lifting a 60kg weight, the one who lifts it the quickest has better explosive strength.
There are two components of explosive power. First, starting strength, which is your natural ability to recruit muscle fibres. Although a personal trainer can help you improve this ability through regular training, the better your explosive power when you start out, the more muscle fibres you are naturally able to recruit. The second component is acceleration strength, which is your ability to continue to engage and recruit muscle fibres behind a movement.
Strength endurance is about keeping as strong as possible for as long as possible. It’s essentially about how many times you can repeat a movement, whether it’s a bench press, a lunge or a squat.
A personal trainer may find that a client who is used to carrying out five or six reps on a bench press will struggle if they join a body pump class and are expected to do the same exercise with a lower weight for a longer period of time. This is because the energy system they need to recruit for the second exercise will not be as well developed.
A regular in the body pump class may appear slighter in build, but if their muscle fibres are conditioned for endurance, they will do better in that exercise. So fitness can be measured in the ability to continuously repeat a movement as well as the ability to lift heavier weights a shorter number of times.
Relative strength is the weight someone can lift or the repetitions they can achieve relative to their body weight. If a fitness instructor is working with two clients who can both lift 100kg but one weighs 85kg and the other weighs 65kg, the latter has better relative strength as the weight they are lifting in proportion to their own weight is a lot higher. This can also be expressed as a percentage, if someone weighs 100kg and they are able to lift 110kg, then they are lifting an extra 10% or 1.1 of their body weight.