A Study Of Free Weights Vs Machines

a study of free weights vs machines

One of the controversies when prescribing resistance training programs is whether the use of free weights or machines is better for building muscle mass and strength.

gym pictures

A major difference between Training with machines and Training with free weights:

Training with machines – provides a very stable environment

Training with free weights – requires more stabilisation and balance, resulting in greater muscle recruitment.

Using free weights compared with more stable machines results in greater muscle activation. The increased muscle recruitment during free-weight activities can provide a more anabolic stimulus. 

Based on many studies, free-weight squat exercise results in greater release of anabolic hormones such as free testosterone and growth hormone leading to greater muscle hypertrophy and strength over time than the more stable leg press exercise.


A 2020 study aimed to compare the effects of training with only free weights or machines on anabolic hormone response, measured by free testosterone levels, muscle mass, and strength.

PMID: 32358310

The researchers hypothesised that free-weight training would result in greater increases in free testosterone concentration, muscle mass, and strength compared with training with machines over 8 weeks.

free weight training


46 healthy subjects volunteered for the study (20 men and 26 women, aged 18–30 years) and were randomised into the machine or free-weight training groups.

The free-weight group did not differ compared with the machine group:

chart study

The free-weight exercises included the flat barbell bench press, incline barbell bench press, bent over barbell row, chin-ups, supine elbow extension, and dumbbell kickbacks. 

The machine exercises included the smith machine flat and incline bench press, seated row, lat pulldown, machine triceps press-down, and rope press-down (pulley system)

The exercise program lasted for 8 weeks and consisted of a 2 days on and 1 day off cycle. Participants trained 4-5x per week with the same number of sets per muscle group. 

study chart

Intensity was increased throughout the program to achieve progressive overload. The exercise program also increased load as volume decreased to mimic a taper effect, which has been shown to promote strength. 



There were no differences in lean tissue mass over time or between groups. Biceps and quadriceps muscle thickness increased with no difference between groups. Free-weight bench press and squat and Smith machine squat strength increased in both groups, with no difference. (11-19%)

Men in the free-weight group had a greater increase in free testosterone from before to after acute training sessions than men in the machine group.

graph chart


The results of the study show that significant increases in strength and biceps and quadriceps muscle thickness can be achieved by training with only free weights or only machines. Men training with free weights have an acute increase in free testosterone after an acute resistance training session, but this does NOT mean it will lead to greater muscle strength and size.


The results of the suggest that muscle size and strength can be increased to the same degree with either training free weights or machine. It’s best to mix and match some exercise selections, such as compound lifts (bench,squat, & deadlift) usually use free weights, while isolation exercises use machines.

P.S You can buy any 3 items from our new range for £50 (saving you £25), We ship globally too.

Use code “3for50” to apply the discount.

rugby clothing
Leave a Reply

Your email address will not be published. Required fields are marked *

For all support queries please email sales@rugbywarfare.com