Using historical controls to evaluate resistance training-induced strength adaptations: Does history repeat itself?

Area of Science:

• Exercise Physiology
• Sports Science
• Biostatistics

Background:

• Historical control groups are sometimes used in resistance training research.
• Their appropriateness for quantifying strength changes and variability is debated.

Purpose of the Study:

• To evaluate the efficacy of historical control groups in resistance training studies.
• To assess their ability to measure one-repetition maximum (1RM) strength changes and variability.

Main Methods:

• Reanalyzed data from three resistance training studies.
• Compared historical controls with time-matched, non-exercise controls.
• Assessed statistical significance, effect sizes, and inter-individual variability.

Main Results:

• Historical controls showed statistically significant strength increases for high-load training, similar to non-exercise controls.
• Effect sizes were biased when using historical controls.
• Low-load training and inter-individual variability analyses yielded inconsistent results with historical controls.

Conclusions:

• Historical controls may be suitable for large, group-level effects in high-load training.
• They lack consistency for low-load training interventions.
• Their use in assessing inter-individual variability in strength gains is questionable.