Choosing the right weight is one of the most common questions people have when they start lifting. And as always, the honest answer is: it depends. But that doesn’t mean picking the right weight is random.
There are useful guidelines that can help you choose weights that are challenging enough to drive progress without interfering with recovery or technique. Learning how to pick the right load is a skill, and like any skill, it improves with practice.
Why Choosing the Right Starting Weight Matters
When you strength train, your general goal (no matter what you’re training) is to create enough stimulus to drive adaptation without creating too much fatigue.
When your weight is too light, you’ll know. You could easily do 15+ reps and think to yourself, “that was easy”. When your weight is too light, you aren’t creating enough stimulus to promote any muscle growth.
On the other end of the spectrum, when the weight is too heavy, your form breaks down and limits your range of motion, which can trigger joint stress, fatigue, or injury instead. During a workout, total volume is one of the biggest drivers of muscle growth, and excessive fatigue lowers the amount of quality work you can accumulate, and definitely messes with your recovery. You’ll know if you’re lifting too heaving because you might feel like you aren’t recovering between workouts, or you feel like you’re training to failure.
Think about getting a “perfect” weight for a lift more-so as a small range as one perfect number. Meaning, sometimes the right weight might not be available to you, sometimes you can lift heavier than other days, and sometimes you’re learning a new movement. The right weight allows you to train hard enough to stimulate progress while still recovering in time to repeat the work again later in the week. It’s a balance of proper weight that can slightly fluctuate that leads to consistent results.
What is RPE and Reps in Reserve?
To figure out what is the best weight for you, you need to understand what RPE and RIR means. RPE stands for Rate of Perceived Exertion. It’s a way to measure how hard a set feels on a scale from 1 to 10.
RPE is measured by how many Reps in Reserve (RIR) or how many more reps you could complete before reaching failure. RIR is used to calculate RPE.
An RPE 7 means you likely have about 3 reps left.
An RPE 8 means about 2 reps left.
An RPE 9 means maybe 1 rep left.
Training to Failure vs Stopping at 8–9/10 Effort
Consistently and complete form matters for these reps. If you’re working out with an RPE of 8, and feel like you’re grinding the last rep or two but still keeping form, that’s ideal.
If you are doing the last two reps by “muscling through” and form is seriously starting to give out, you could potentially be doing damage to your joints, increasing fatigue, and stalling your progress – consider lightening your weights.
This gives you a feel for what training to failure actually feels like. It means your form would start to completely deteriorate, you feel yourself utilizing other muscles that are not targeted, and you feel like you genuinely could not do another rep (listen to your body and not your mind for this).
RPE changes consistently. It might go up during a mesocycle, and definitely up over time, and it might actually go down on days you’re exhausted, on your cycle, not feeling 100% or after a break.
Another great piece of information for your back pocket is that different lifts can sometimes be pushed to failure, while others don’t need to be and probably shouldn’t. Compound lifts like squats, deadlifts, presses, and rows involve more joints and create more systemic fatigue. Because of that, they usually don’t need to be pushed all the way to failure to be effective.
Isolation exercises like curls, lateral raises, leg extensions, or hamstring curls create less overall fatigue and are often safer to take closer to failure.
How to Determine What Weights to Start With
Where you are in your strength training journey determines what your RPE is. Beginners should usually stay around an effort level of 6 out of 10, and maybe 7 at most. This feels like being completely able to workout with optimal form every rep and challenging yourself.
When you’re beginning training, your focus is less on pushing limits and more on learning proper form. The good news is, your body will still change drastically in a short amount of time, even with light weights. In fact, beginners see the quickest and most radical changes because of the new adaptations your body is going through.
Practicing lifts with lighter weights gives your nervous system time to learn efficient movement patterns with a full range of motion and stable joints. This motor learning is what allows you to safely handle heavier loads later. Remember, if technique is spot on at first first, maximum strength gains will follow with the smallest likelihood of injury.
This approach also applies if you’re an intermediate lifter but trying a new movement for the first time, returning after a long break (2+ months) or coming back postpartum. Your body remembers, but it still needs time to rebuild coordination and tolerance to training stress.
Starting lighter gives you room to improve without unnecessary setbacks.
If you’re an intermediate or recreational lifter, aiming to have an RPE of an 8 for each movement can be the perfect intensity to train in for muscle hypertrophy with adequate recovery.
Common Mistakes Beginners Make
We don’t like to make generalizations, but in our time coaching, we see one of two things: someone either doesn’t want to lift too heavy and is afraid of getting injured, or someone goes way too hard. Think for a minute about what category you might fall into. Let that be a reminder for you to either push harder or let your ego before you damage your progress.
This discrepancy between lifting too light or heavy weight is where we see the most common mistakes that beginners make.
Lifting too Heavy
Chasing heavier weights before technique is consistent compromises longevity. Form breaks down early, fatigue builds quickly, you aren’t getting a full range of motion to work the ENTIRE muscle, joints take the load, injury risk increases, and progress often stalls.
Lifting too Light
The opposite mistake is never increasing the challenge. If every set feels easy and you never approach fatigue, your body has no reason to adapt. In short, lifting light minimizes muscle growth, which is the entire reason you’re strength training to begin with.
Adjusting Weight Across Different Rep Ranges
Lower rep ranges require heavier weights. Higher rep ranges require lighter weights. But the effort level should stay similar.
For example, a set of 5 reps and a set of 12 reps might both fall around RPE 7–8. The number of reps and weight for the same movement changes, but the level of challenge does not. Over time, you’ll develop a sense for the weights you typically use at different rep ranges.
How to Progress Weight Safely Over Time
Progression works best when technique stays consistent. Stay lighter to hit an RPE of 6 until your form feels solid and you know what you’re doing, especially for compound lifts. Once your technique feels good, small increases in weight can be added gradually to increase your RPE to an 8.
If you’re training on your own and without a trainer physically present or checking your form online, you can look at YouTube videos for form explanations or ask questions in a safe online forum, like the Stronger Than Your Boyfriend Facebook Group.
As you spend more time training, you’ll start to recognize the loads that match different rep ranges. You can use those as a baseline and build from there when possible.
Progress in weights rarely happens every session. For example, you may or may not change a weight for a movement in a single mesocycle. However, even with the same weight, you should notice that the movement feels more controlled and you feel stronger than you did before. You might even notice your form refining. Sticking to a workout routine over months is what actually moves weight up gradually.
Signs You’re Lifting Too Light or Too Heavy
Signs the Weight Is Too Light
- You might finish sets feeling like you barely worked
- You don’t approach fatigue
- You stay at the same weight for months with no challenge
- You leave your sessions feeling bored or you could have worked out more
- You aren’t noticing any strength gains or body composition changes over a longer period of time
Signs the Weight Is Too Heavy
- Breaking form early
- Holding your breath excessively
- Joint pain instead of muscle fatigue
- Needing huge rest times
- You start to feel other muscles compensating towards the end of a rep
- Fatigue that interferes with the rest of the workout
- Fatigue that interferes with the rest of your day
Choosing Weights With Confidence
Learning to choose weights confidently takes time.
One useful concept to know is autoregulation: adjusting your training based on how your body feels and performs that day instead of forcing predetermined numbers.
This is harder for beginners, but it gets easier with experience. As you accumulate more training sessions, you begin to understand your recovery patterns and your tendencies.
When you are lifting, incorporating a mind-muscle connection can also help you understand what weights you need and fully maximize each movement. This takes presence and understanding what muscles are being worked and where they are in the body. The more thoughtful reps and sets you put in, the better your instincts become.
Choosing the right weight isn’t about guessing perfectly. It’s about making informed adjustments and improving your judgment over time.
Want to learn more about choosing the right weight? Listen to episode 276 of the Stronger Than Your Boyfriend Podcast: How to Choose the Right Weight
