Key Summary of the Study on Personal Trainers
- Personal trainers led to greater muscle gains, fat reduction, and injury avoidance than solo or partner training.
- Partner-based training boosts motivation through competition but was second to training with a personal trainer.
- Personal trainers reported fewer injuries and greater adherence to a structured dietary plan than solo and partner training groups.
Personal Trainers are Only for Beginners, Right?
Personal trainers -supervised training is now widely recognized as a top fitness trend. According to the 2022 Worldwide Survey of Fitness Trends, personal trainer-supervised training is rated third in Europe, first in Brazil, seventh in Australia, and eighth in the United States, indicating its expanding global popularity.1
Hiring a personal trainer is often considered unnecessary for those training hard to gain muscle, especially for those with years of gym experience. It was commonly believed that training with a partner or solo could yield similar results. However, A study led by Yunhang Lu and colleagues, published in the esteemed journal Heliyon, reveals that training under the supervision of a personal trainer delivers faster and safer results than training alone or with a partner.2 This research compared the effectiveness of individual, partner, and personal trainer-supervised training across 12 weeks. The findings are clear: personal trainers offer unmatched benefits in achieving strength, fat loss, and injury prevention.
Are Personal Trainers Worth the Money?
Research consistently shows that personal trainers empower clients to achieve better results than other training methods. Ratamess et al. (2008) found that individuals training under the supervision of a personal trainer lifted heavier weights and trained at higher intensities than those working out alone.3 Participants in the trainer-supervised group lifted weights at an average of 51.4% of their maximum capacity compared to 42.3% for the solo group. Similarly, Storer et al. (2014) discovered that participants in personal trainer-supervised programs improved their leg press strength by 13% and gained 2.9 pounds (1.3 kilograms) of lean body mass, while solo trainees showed no such improvements.4 Additionally, Melton et al. (2008) noted that personal trainers played a critical role in injury prevention by ensuring proper exercise form.5
The Role of Motivation in Training
While partner training offers some advantages—such as enhanced motivation through competitiveness—it lacks a personal trainer’s personalized approach and expertise. For instance, Mazzetti et al. reported that 12 weeks of supervised resistance training promoted greater increases in one-repetition maximum (1RM) squat and bench press compared to strength increases seen in an unsupervised group.6 Furthermore, the absence of structured programming often seen in peer training scenarios may hinder optimal progress compared to the tailored programs created by personal trainers.7
Study Protocol Research Design: Personal Trainers vs Training Partners vs Solo Training
The study split participants into three groups to compare the effectiveness of training approaches.
- Individual Training: Participants exercised alone using pre-designed training regimens.
- Partner Training: Participants worked in pairs to promote mutual motivation and competitiveness.
- Personal Trainer-Supervised Training: Participants worked with qualified personal trainers who created and oversaw individualized programs based on their requirements.
Over 12 weeks, participants did three training sessions each week, with an emphasis on upper and lower body resistance exercises and 30 minutes of aerobic activity at 55-65% of maximal heart rate. The key outcomes assessed were strength increases, fat reduction, dietary plan adherence, and injury rates.
Key Findings: The Superiority of Personal Trainers for Gains
Strength Gains:
- Participants in the personal trainer-supervised group enhanced their bench press strength by 43 pounds (19.7 kilograms) and their squat strength by 80 pounds (36.2 kilograms).
- Partner training resulted in modest improvements of 41 pounds (18.6 kilograms) in the bench press and 58 pounds (26.3 kilograms) in squats.
- Individual training exhibited minimal enhancements, with increases of 23 pounds (10.4 kilograms) in the bench press and 44 pounds (20 kilograms) in squats.
Hypertrophy
Muscle hypertrophy (i.e., muscle growth) was assessed by changes in skeletal muscle mass among all groups:
- Personal Trainer Group: Attained the most muscle gain, averaging an increase of 1.38 kilos (3.04 pounds).
- Partner Training Group: Experienced significant enhancements, acquiring 1.16 kilos (2.56 pounds) of muscle.
- Individual Training Group: This group had the least growth, achieving about 0.33 kilos (0.73 pounds).
Adipose Tissue Reduction: The group supervised by a personal trainer was the sole cohort to achieve significant fat loss, averaging a decrease of 3.5 pounds (1.61 kg). Both partner and solitary groups had no significant changes in fat mass.
Nutritional Compliance: Participants collaborating with personal trainers complied with their meal plans at a rate of 81%, whereas the partner group adhered at 47% and the solitary group at 43%.
Injury Rates: The personal trainer-supervised group had decreased injury rates, reporting just 60 injuries, in contrast to 167 in the partner training group and 188 in the solo training group.
Why Personal Trainers Led to Better Results
The study determined that the personal training group surpassed the others due to numerous critical criteria. The oversight and encouragement offered by personal trainers allowed participants to utilize greater weights and intensities, hence optimizing their performance in resistance training. The trainers also enforced a disciplined dietary regimen of high-protein, low-fat, and controlled-carbohydrate meals, leading to a notable decrease in fat mass not seen in the other groups. Additionally, personal trainers emphasized injury prevention by overseeing exercise techniques and modifying intensity, reducing injuries and discomfort. Their focus on comprehensive training, addressing all primary muscle groups, particularly the legs, resulted in significant enhancements in lower-body strength, exemplified by improved squat performance. Moreover, participants gained from the trainers’ proficiency in nutrition, enabling them to adhere continuously to meal plans created for maximal fat reduction and muscle development.
References
1 Martinez Kercher, V. et al. 2022 Fitness Trends from Around the Globe. ACSM s Health & Fitness Journal 26, 21-37 (2022). https://doi.org/10.1249/FIT.0000000000000737
2 Lu, Y. et al. Comparing the impact of personal trainer guidance to exercising with others: Determining the optimal approach. Heliyon 10 (2024). https://doi.org/10.1016/j.heliyon.2024.e24625
3 Ratamess, N. A., Faigenbaum, A. D., Hoffman, J. R. & Kang, J. Self-selected resistance training intensity in healthy women: the influence of a personal trainer. J Strength Cond Res 22, 103-111 (2008). https://doi.org/10.1519/JSC.0b013e31815f29cc
4 Storer, T. W., Dolezal, B. A., Berenc, M. N., Timmins, J. E. & Cooper, C. B. Effect of supervised, periodized exercise training vs. self-directed training on lean body mass and other fitness variables in health club members. J Strength Cond Res 28, 1995-2006 (2014). https://doi.org/10.1519/jsc.0000000000000331
5 Melton, D. I., Katula, J. A. & Mustian, K. M. The current state of personal training: an industry perspective of personal trainers in a small Southeast community. J Strength Cond Res 22, 883-889 (2008). https://doi.org/10.1519/JSC.0b013e3181660dab
6 Dias, M. R., Simão, R., Saavedra, F. & Ratamess, N. A. Influence of a Personal Trainer on Self-Selected Loading During Resistance Exercise. The Journal of Strength and Conditioning Research 31, 1925-1930 (2017). https://doi.org/10.1519/jsc.0000000000001663
7 Kassiano, W. et al. Is the Rating of Perceived Exertion Planned by the Personal Trainer Similar to Subject’s Perception? A Pilot Study. Brazilian Journal of Kinanthropometry and Human Performance 22 (2020). https://doi.org/10.1590/1980-0037.2020v22e63257
