Influence of a Personal Trainer on Self-selected Loading During Resistance Exercise

Area of Science:

• Exercise Physiology
• Sports Science
• Strength and Conditioning

Background:

• Optimizing resistance training intensity is crucial for maximizing muscle strength and hypertrophy.
• Self-selected training loads may not always reflect true maximal capacity without external guidance.
• The role of personal trainers in modulating training intensity requires further investigation.

Purpose of the Study:

• To compare muscle strength and self-selected resistance training intensities between supervised and unsupervised training groups.
• To determine the influence of a personal trainer on the loads lifted during resistance exercise.
• To analyze differences in relative training intensities (percentage of 1RM and 10RM) and perceived exertion.

Main Methods:

• Twenty-one trained subjects (12 men, 9 women) participated in three sessions: self-selected load assessment, 1 repetition maximum (1RM) testing, and 10RM testing.
• Subjects performed leg press, bench press, leg extension, and arm curl exercises.
• Training loads were self-selected under personal trainer (PT) supervision or without supervision (WoPT).

Main Results:

• Self-selected training loads were significantly higher in the PT group compared to the WoPT group for all tested exercises (LP: +15.6%, BP: +26.6%, LE: +12.1%, AC: +22.2%).
• Relative to 1RM and 10RM, self-selected loads were significantly higher in the PT group (49-59.5% of 1RM; 62.7-77.3% of 10RM) than in the WoPT group (41-58.7% of 1RM; 58.7-76.2% of 10RM).
• Ratings of perceived exertion were significantly higher in the PT group, indicating a greater training intensity.

Conclusions:

• Supervised resistance training with a personal trainer leads to significantly higher self-selected training loads in trained individuals.
• Personal trainer supervision appears advantageous for optimizing training intensity, particularly for lower-body exercises.
• Despite increased loads, self-selected intensities remained below established 1RM and 10RM percentages, suggesting potential for further intensity manipulation.