How Much Lean Muscle Can We Gain?

One of the most common questions I hear from women in their forties and beyond is how much muscle they can realistically expect to build once they begin strength training. The good news is that it is absolutely possible to gain, or regain muscle and significantly improve strength, posture, shape and metabolic health at any age. The key is having realistic expectations and following a structured, progressive approach.

For most women over 40 who are new to strength training, the expected gain in actual lean muscle tissue is around 1 to 2 kilograms over a 12-month period. That might sound modest at first, but in reality it is a substantial amount of metabolically active tissue that can completely change the way your body looks and functions. A very good result, particularly for women who have been under-muscled or detrained for some time, is 1.5 to 3 kilograms across the first 18 to 24 months.

Muscle gain at this stage of life is slower than in younger decades, largely due to hormonal changes. From perimenopause onwards, women experience lower levels of oestrogen, reduced responsiveness to protein, slower recovery and a naturally reduced anabolic response to training. None of this means you cannot build muscle - it simply means you need the right strategy.

One of the biggest misconceptions is that visible changes in strength mean you have built large amounts of muscle. In the early stages of training, almost all the improvement you feel comes from neurological adaptation - your brain and nervous system becoming more efficient at recruiting the muscle you already have. Real muscle gain takes consistency over months and years, not weeks.

To maximise results, a few key factors must be in place. First, progressive overload: weights, reps or training volume need to increase gradually over time. Random workouts or light pump-style sessions will not stimulate meaningful muscle growth. Adequate (and high quality) protein is also essential, with most women needing more than they realise. For decades women have been conditioned to aim for ‘small’ and ‘light’, rather than ‘strong’.

Quality sleep, stress management and optimal levels of nutrients, such as iron and vitamin D play a major role in recovery. Without these foundations, progress slows dramatically.

The most encouraging part? Even 1 to 2 kilograms of muscle can create a remarkable transformation. Shoulders lift, the waist looks more defined, posture improves and metabolism becomes far more efficient.

At any age, but especially beyond 40, strength training is one of the most powerful investments you can make in your long-term health, bone density and vitality.