Free Weights vs Machines for Muscle and Strength Gain

Article: Free Weights vs Machines for Muscle and Strength Gain

When designing resistance training programmes, the variety of exercises at a coach’s disposal is enormous. Generally, these exercises can be grouped into two main categories: free weight exercises, and exercises performed on machines.
Before diving into which form of training is best, let’s define what each one consists of:

• Free weights – training performed with barbells, dumbbells, kettlebells etc. where we are moving the weight through a “free” range of motion. Free weights provide a constant resistance throughout the range of motion of the exercise.
•  Machines – plate and pin-loaded machines such as leg press, chest press, smith machine etc. where weight is moved through a fixed path. Some machines allow for the resistance to be varied throughout the range of motion of the exercise.

The main difference between these types of training is the additional requirements for stability and balance associated with training with free weights. Many have argued that this will lead to greater recruitment of muscle and therefore greater muscle and strength gain over time.

But what does the scientific evidence say?
Recent studies indicate that free weight and machine training are equally effective for muscle and strength gain (Schott, Johnen, and Holfelder, 2019), despite the fact that free weight training has been found to acutely increase testosterone in men following a resistance training session (Schwanbeck et al., 2020).

Nevertheless, this does not mean that these types of training will be equally effective for all people in all situations. For prevention of injury, free weight training is clearly superior since these exercises target stabilizer muscles along with the prime movers. This is crucial since joint stability is a key aspect of injury prevention (Huxel Bliven and Anderson, 2013). Additionally, free weight training is much more transferrable to both sporting situations and real-world lifting movements.

However, training with machines may be advantageous when trying to isolate individual muscle groups which need particular focus. For example, the leg press and leg extension machines allow us to train the quadriceps without being limited by the strength of the back or glutes. This may be beneficial for those recovering from particular injuries. Another benefit of machines is that some may have a superior strength curve compared to some free weight exercises whereby more tension is placed on the muscle in a stretched position. This is important since our muscles may produce more/less force at certain muscle lengths (Haff, 2000).

Overall, it seems that a mix of free weights and machine training may be beneficial, although primary focus should be on free weight exercises with machines reserved for secondary assistance exercises.

Summary

• Free weight and machine training are equally effective for muscle and strength gain
• Free weight training recruits stabiliser muscles more, making these exercises superior for injury prevention
• Free weight exercises are more transferable to real-world activities and athletic performance
• Machines are useful for isolating individual muscle groups
• Some machines have a superior strength curve to free weight exercises

References
Haff, G.G., 2000. Roundtable discussion: Machines versus free weights. Strength & Conditioning Journal, 22(6), p.18.
Huxel Bliven, K.C. and Anderson, B.E., 2013. Core stability training for injury prevention. Sports health, 5(6), pp.514-522.
Schott, N., Johnen, B. and Holfelder, B., 2019. Effects of free weights and machine training on muscular strength in high-functioning older adults. Experimental gerontology, 122, pp.15- 24.
Schwanbeck, S.R., Cornish, S.M., Barss, T. and Chilibeck, P.D., 2020. Effects of training with free weights versus machines on muscle mass, strength, free testosterone, and free cortisol levels. The Journal of Strength & Conditioning Research, 34(7), pp.1851-1859.