This Study wanted to see which of two (Free-Weight vs. Machine-Based) training methods was better to improve Maximal Strength, Hypertrophy and Jump Performance.
1 ) Maximal Strength
The free-weight group increased strength more when both groups were tested in free-weight exercises, and the machine group tended to increase strength in machine exercises more than the free-weight group.
However, when used a neutral test (isometric strength test), both groups showed similar results.
This follows a KEY principle of strength training which is the Principle of Specificity.
This principle states that “the way the body responds to physical activity is very specific to the activity itself.”
2 ) Hypertrophy
No difference was found between free-weight and machine-based strength training for hypertrophy.
Both training groups induced similar hypertrophic gains during the strength training interventions lasting nine weeks on average.
However, the degree of failure in the main muscles with free-weight exercises could be limited by failure in smaller synergist muscles and a failure to conduct the exercises with proper techniques.
Therefore, it could be speculated that machines can train the main muscle group(s) closer to failure and thus induce more gains in the main muscles of the exercise.
It should also be taken in consideration that, although the results showed similar results for both groups for hypertrophy, exercises that allow a greater stretch of the main muscle group(s) that we want to train, will also allow for more muscle growth (PMID: 36662126).
This means that, if two exercises share the same ROM it doesn’t seem to matter that much which of the two you choose.
But if one allows a bigger stretch, that one will produce better results.
3 ) Jump Performance
Same as before, no difference was found between free-weight and machine-based strength training in jump performance.
However, If your main goal is to have the best performance and improvement possible in a specific Jump, you should also take in consideration the Principle of Specificity here, and train specifically with the jump that you want to improve. Only the complementary exercises are of free choice.
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