How to assess your One Repetition Maximum (1RM) for strength training
Nigel Hetherington explains how to assess your one-repetition maximum (1RM) for strength training.
When seeking to develop strength, power or explosiveness for your event knowing your 1RM is essential to develop the appropriate component in a structured manner i.e.
Not knowing in which region you are working is pointless. Furthermore, the ability to assess your 1RM for a given exercise, without having to lift that weight, has clear advantages in terms of safe practice, minimising the chance for injury and allowing those whose specific lifting technique may not yet support maximal repetitions to gain benefits.
As a fitness component, we can plan to generate measurable improvements in strength (as well as power or explosiveness) within 6 to 8 weeks. It has been understood for some years now that there is a linear relationship between the number of repetitions to exhaustion with a given resistance and the % your 1RM. A convenient formula exists to allow us to make the calculation:
Predicted IRM = Weight lifted ÷ (1.0278 - 0.0278x)
Where 'x' is the number of repetitions to exhaustion
What this means is that, say, in a half squat you can perform ten repetitions at 100kg your calculated 1RM using the equation above would be 133kg. In reality, to establish a more robust value, we will need to perform lifts to exhaustion at different resistances. Several approaches are possible:
Calculating 1RM in a session
Ensure you are familiar with the lift you are about to perform and that, where appropriate, you have a 'spotter' - particularly when working with free weights.
Ensure you are fully warmed up and that the equipment is safe. You should not be fatigued when lifting. The same approach may be taken for several different lifts in one session. Treat this as a training session in itself and perform it in a warm, comfortable environment. Gently cooldown afterwards.
Do not strain when lifting - reproducible efforts with a consistent and good technique will provide the safest and most reliable adaptation.
Use the calculated 1RM to calculate appropriate loadings for hypertrophy, power or explosiveness training as given above.
Re-assess your 1RM from time-to-time as this value will change and determines the resistances used in the various workouts. Record all sessions! Devise a maintenance program once your goal is achieved.
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About the Author
Nigel Hetherington was the Head Track & Field Coach at the internationally acclaimed Singapore Sports School. He is a former National Performance Development Manager for Scottish Athletics and National Sprints Coach for Wales. Qualified and highly active as a British Athletics level 4 performance coach in all events he has coached athletes to National and International honours in sprints, hurdles as well as a World Record holder in the Paralympic shot. He has ten years of experience as a senior coach educator and assessor trainer on behalf of British Athletics. Nigel is also an experienced athlete in sprint (World Masters Championship level) and endurance (3-hour marathon runner plus completed the 24 hour 'Bob Graham Round' ultra-endurance event up and down 42 mountain peaks in the English Lake District). He is a chartered chemist with 26 years of experience in scientific research and publishing.