Devlin Brown at the Water Cooler | Strength training: benefits of heavy and light lifting

I know this is a typical male question, but how heavy should I be lifting? I see two extremes at the gym. Some attempt to lift so heavy the weight barely moves, while others train slowly with so little weight I often wonder, “What’s the point?” Is there a right way to train?

There are two extremes on the weight-training spectrum. If you are training to be a powerlifter or weightlifter it matters how much you can lift, whereas if your goal is to grace a bodybuilding stage or join the Fourways peacock parade, it doesn’t.

Two caveats: even powerlifters should periodise their training as constant all-out training is not just ineffective at total strength gain over time, it is brutal on the body, especially the central nervous system, joints, ligaments and tendons. While stage competitors aren’t concerned with how strong they are, they need to build up their strength to function as the engine for the aesthetic stuff, while the Fourways boytjies need some functional strength to survive their weekly bust-ups at the bar or LIV golf event at Steyn City.

You gave no context for why you train, so we will presume that it is for general body recomposition, functional strength and fitness, and overall wellness and longevity. If this is accurate, you need to do both: lift heavy for functional strength gains and lift moderately with higher volume for increased metabolic stress.

If you are middle-aged, remember you are not 25. Recovery is just not the same, meaning you need to be wise with how you mix up heavy lifting, lighter training, your exercise frequency and the volume of your workouts.

Let’s settle what “heavy” means. What’s heavy for me may not be heavy for you. Unlike those guys at the gym who lift so much that it barely moves, think about it in terms of your own one-rep max (1RM). A 1RM is the total amount of weight you can lift for one repetition.

Heavy lifting is typically 80% or more of your 1RM. If your one-rep maximum on the bench press is 100kg, training with 80kg or more is considered heavy. Moderate lifting is typically about 60%-75% of your 1RM. Heavy lifting necessitates fewer reps, while moderate lifting allows for more repetitions. Don’t try to do 15 reps if you are lifting 90% of your 1RM — you will lose form and hurt yourself.

Assuming everything is done with the right, strict form, both types of training have been proven to trigger muscle growth and strength gains. Heavy lifting is more about mechanical load and leans more towards strength gains while moderate lifting is more about metabolic stress and leads to the “pump”. It is more geared to increasing muscle size.

Let’s dig deeper. Heavy lifting is more biased towards myofibrillar hypertrophy, the development of actual contractile proteins (actin and myosin) inside muscle fibres. It makes muscles denser, stronger and more powerful. It directly boosts force production, strength-to-size ratio and bone density. It is harder to gain and it takes longer to lose.

Lighter training tends to lead to more sarcoplasmic hypertrophy, the expansion of the noncontractile fluid, glycogen, mitochondria, and other “support” material around the fibres. It increases muscle volume and creates that full, pumped look while boosting work capacity and metabolic efficiency. It is quicker to build but quicker to lose.

Think of a man, probably with a receding hairline or none on the top at all, who has lifted for many years, with dense, granite-like arms compared with a 20-something who’s been in the gym for a year, who walks around with balloons coming out of his sleeves. That would be an extreme visual representation. Real life is more of a crossover. I’ve trained with aesthetic bodybuilders who are unbelievably strong and alongside powerlifters so lean they wouldn’t look out of place on the stage or the Sea Point promenade at rush hour.

While both types of muscle gain will happen to some degree with both types of training, you really want to get a healthy mix of heavier and more moderate lifting, not only for overall balance, but also for longevity and enjoyment in the gym.

If longevity is your goal, try not to obsess about how much you lift or how “buff” you look. Worry about following a carefully periodised programme to get the best out of strength training.