How Heavy Should I Lift? A Simple Guide for Beginners

You walk up to the rack of dumbbells or kettlebells and freeze. The 4kg looks too easy. The 12kg looks like it might break you. You pick something in the middle, do your reps, and leave not knowing if it was right. If you have ever asked yourself how heavy should I lift, this post gives you a simple answer that works for every exercise: reps in reserve. Then I will show you a quick test for each of the main moves so you can choose your weight in under a minute.

The simple answer: reps in reserve

“Reps in reserve”, or RIR, means how many more reps you could have done at the end of a set with good form. If you do 10 squats and honestly could have done 3 more, that set was at 3 RIR.

For most busy parents training for strength, health and shape, I aim for 2 to 3 reps in reserve on most sets. That means:

• The last couple of reps feel hard and slow down a little.
• Your form stays solid all the way through.
• You stop before you grind, wobble or hold your breath to finish.

This is heavy enough to make you stronger, but not so heavy that you are wrecked for the school run or risk a tweak.

A quick RIR scale

• 5 or more in reserve: too light for strength work. Great for warm-ups.
• 3 to 4 in reserve: good for beginners in their first few weeks and for learning technique.
• 2 to 3 in reserve: the sweet spot for most sets.
• 1 in reserve: occasionally, on the last set, if you are experienced.
• 0 in reserve: going to failure. Rarely needed and not something I recommend for beginners.

How heavy should I lift for my goal?

Pick a rep range, then pick a weight that leaves 2 to 3 reps in reserve inside that range.

• Getting stronger: 5 to 8 reps.
• Building muscle and shape: 8 to 12 reps.
• General fitness and muscular endurance: 12 to 15 reps.

All three ranges build strength and muscle to some degree. For most parents, 8 to 12 reps is a great place to live most of the time.

The NHS recommends strength activities that work all the major muscle groups on at least 2 days a week, and says to work to the point where you find it hard to do another repetition. You can read their advice on strength exercises.

A simple test for each main move

Use this 3-step test for any exercise:

1. Pick a weight you are confident is a bit light. Do 8 reps.
2. Ask: “How many more could I have done with good form?” Be honest.
3. If the answer is 5 or more, go up a size. If it is 2 to 3, that is your weight. If it is 0 to 1, go down.

Below are starting points and specific checks for the five moves I use most with beginners.

Goblet squat

Start with: 6 to 10kg for most women, 10 to 16kg for most men (very rough starting points). Check: can you keep your chest up and heels down on the last rep? If your back starts rounding or the weight pulls you forwards, it is too heavy, even if your legs could do more. Form rules. See my goblet squat guide for cues.

Kettlebell or dumbbell deadlift

Start with: usually heavier than your squat, often 12 to 20kg. Check: does your back stay flat and does the weight stay close to your legs? If you feel it in your lower back rather than your bum and hamstrings, drop down. My kettlebell deadlift for beginners post explains the hip hinge.

One-arm row

Start with: similar to your squat weight. Check: can you pull without twisting your body or yanking? If your torso rotates to finish the rep, it is too heavy.

Overhead press

Start with: lighter than you expect, often 4 to 8kg per hand. Check: can you press without arching your lower back or leaning back? If your ribs flare out, go lighter.

Push-up

No weight to choose, but the same rule applies. Pick the height that leaves 2 to 3 reps in reserve at 8 to 12 reps: wall, kitchen worktop, sofa arm, knees or floor. My push-up progression shows each step.

If you are buying a kettlebell for home, my guide on what weight kettlebell to start with will save you money.

When to go heavier

Use the “two extra reps” rule. When you can do 2 more reps than the top of your range, on all your sets, with good form, move up to the next weight. For example, if your range is 8 to 12 and you have hit 14 reps on every set of goblet squats, move up a size and drop back to 8.

Kettlebells often jump in 4kg steps, which is a big jump. In that case, use the new weight for 1 set and the old weight for the rest, then gradually swap over.

When not to go heavier

• When you have pain, rather than effort. Pain that is sharp, in a joint, or lingers is a stop sign. If you have a back, knee or shoulder problem, or a health condition such as osteoporosis or high blood pressure, check with your GP or physio before lifting heavier, and see the NHS advice on back pain.
• When you are pregnant or recently postnatal. Get your GP check, usually around 6 to 8 weeks after birth, before returning to exercise, and follow the guidance from your midwife, GP or physio.
• When your form slips. A lighter weight done well beats a heavier one done badly.

Choosing weights in a bootcamp class

In my classes, I set out a range of kettlebells and dumbbells for each station, and I will help you choose on your first session. You will hear me ask “how many more could you do?” a lot. That is RIR in action.

My SYP Built To Last strength class is designed for people over 35 who want to lift properly and safely, with a clear eye on progress from week to week.

FAQs

Is it better to lift heavy with low reps or light with high reps?

Both work if the set is challenging. Research and experience suggest muscle grows across a wide range of reps, as long as you get close to, but not necessarily to, failure. Pick what you enjoy and can do safely.

How heavy should a woman lift?

The same rule applies to everyone: a weight that leaves 2 to 3 reps in reserve. Many women I coach are surprised how quickly they move up. Lifting heavier will not make you “bulky” by accident.

Should I lift heavier every week?

Not necessarily. Adding a rep or two each week is progress too. Increase the weight once you have earned it with the “two extra reps” rule.

Book your first class

Want help choosing the right weights in person? SYP Bootcamp runs 45-minute small-group classes indoors in a church hall in Archway N19, with a maximum of 10 people and £15 a class. I check your form and your weights at every station. Book your £15 class here or call or WhatsApp me on 07301 512215. If you are lifting around an old injury, my injury-safe personal training at SYP Fitness gives you one-to-one support.

About the author

Artem Olekhnovych is a personal trainer in Archway and the founder of SYP Fitness and SYP Bootcamp. He has coached clients in Archway, Highgate and across North London for over 10 years, and runs small-group bootcamp classes for busy mums and dads. Read reviews from his 1-1 clients.