How Heavy Should You Lift? Choosing the Right Weight in the Gym

How do you know whether the dumbbell you have picked up is too heavy, too light or just right? The answer depends on your goal, your technique and how close you are to the limit of the repetitions you can do with control.

Get familiar with reps in reserve

Reps in reserve (RIR) is an estimate of how many more good-quality repetitions you could perform at the end of a set. If you finish eight reps and think you could do another three without changing your technique, that is approximately 3 RIR. It becomes easier to judge with practice.

A sensible starting intensity

For many general strength and muscle-building exercises, finishing with around two or three good repetitions left is a practical starting point. You can work closer to your limit in some situations, but a novice learning a new lift usually benefits from additional margin. Not every set needs to be maximal.

Try the dumbbell-row test

Imagine your plan calls for three sets of ten dumbbell rows. If you finish ten easily and feel you could perform another seven, consider a slightly heavier dumbbell. If you need to swing your torso on rep eight, lighten the load. The aim is ten controlled repetitions at an appropriate level of effort.

Progress means more than adding weight

Progressive overload can mean more reps with the same load, a small load increase, a better range of motion or more consistent technique. When you can achieve the upper end of your prescribed rep range on all sets with the intended effort, that is often a good time to move up slightly.

Keep records, not guesses

Note the load, the repetitions and approximately how demanding each set felt. Review several sessions rather than chasing a record every day. At REVIVAL Personal Training in Hammersmith, structured one-to-one and Small Group Personal Training helps members develop confidence with weights and follow a progression that suits their goals.