Tri-Set (TS) or Multi-Set(MS) Training? MS Sheds More Body Fat & Builds More Strength in Experienced Female Trainees, But Results Show High Inter-Individual Differences

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Don't believe you'd to train different than men, ladies. That's simply not true!

If I look around at the gym, I see 99% of the men do a classic multi-set routine, where you do bench presses for three sets before you move on to flies for three and so on. Circuit training, where you'd do bench presses, flys, triceps extensions, etc. for only one set and hop from one exercise to the other at a fast pace, on the other hand, that appears to be more popular among female trainees - probably because they believe (not without reason) that it's the better fat burner.

If these women knew about the results of the latest study from the Vale of Itajai University, some of them would yet probably be shocked. The question is however: Rightly so?
Before we get to the "shockers", let's first take a look at what Paula Garcia and her colleagues from the Catholic University of Brasilia and the Eastern Illinois University (2014) actually did in their soon to be published study: In view of the "paucity of studies comparing the effects of MS [multiple set] and TS [tri-set] approaches on neuromuscular variables and body composition, the Brazilian & US researchers were interested in the differential effects of doing three sets of one exercise with a long pause in-between vs. doing one set of three exercises without pause in trained subjects.

"Therefore, the objective of this study was to compare the effects of MS and TS RT approaches on muscle strength and body composition following a 12-week programme in trained women (>1 year of RT experience). A secondary objective was to assess possible variations in individual responsiveness to the RT programmes by the identification of high, moderate and low responding subjects. We hypothesized that both training approaches would induce significant improvements in muscle strength with no differences between them and that individual responsiveness would be evident following each training programme." (Garcia. 2014)

Garcia's subjects were eleven women with more than 12 months of resistance training experience participated in this study. They were randomly divided into two groups: the multiple-sets training approach (MS =6) or the tri-sets training approach (TS =5). The use of dietary supplements, hormone treatements or having neuromuscular problems that would compromise their performance during testing and training were exclusion criteria for the subjects, who had to monitor their diets during the 12 weeks to ensure consistency in caloric intake (consistency as defined relative to pre values).

All subjects completed 12 weeks of a lower limb RT program that included the squat, stiff leg deadlift, 45° leg press, leg curl, gluteus in the smith machine and standing calf raise exercises (Cybex International, Medway, MA, USA). The RT sessions were performed three times per week.

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Table 1: Periodization for the multiple-sets (MS) and tri-set (TS) methods (left) and resistance exercises used in the study (right | Garcia. 2014)

Both training approaches consisted of a linear periodized programme (Prestes. 2009), in which intensity was increased every microcycle (2 weeks) whilst volume was decreased (see Table 1).

• The MS group trained as follows: 1st–2nd weeks, three sets of 12–14 RM; 3th–4th weeks three sets of 10–12 RM; 5th–6th weeks three sets of 6–8 RM always leading to repetition failure. This training pattern was then repeated until the completion of 12 weeks (see Table 1). The rest interval between sets and exercises was 90 s. 
• In the TS method, subjects completed three exercises for the lower limb without rest between them; a rest interval was allowed after these three exercises and the same circuit was repeated three times (see Table 1, right). The training periodization was the same for both groups; the only difference was that in weeks 11 and 12, the TS method was included. 

The total training volume was equated between groups. All training sessions were supervised by an experienced strength and conditioning professional.

Skinfold measurements and standardized strength tests - RESULTS!

Body composition was assessed before and after the 12 weeks of training period using skinfold thickness measurements taken with a Lange skinfold caliper. Based on the results of the skinfold measures, fat mass (kg) and fat-free mass (kg) were estimated. Participants were advised to maintain their habitual activities and diet (this was guaranteed by a dietary recall follow-up).

Based on what I said in the introductory paragraphs, the average practitioner would probably expect significant differences with respect to the effects on body composition between the two groups. More specifically, common wisdom would suggest greater increases in muscle size in the multi-set and greater reductions of body fat in the tri-set group, respectively.

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Figure 1: Changes in body composition in response to 12-week periodized MS vs. TS training (Garcia. 2014)

Surprisingly (?), a brief glimpse at the data in Figure 1 indicates that the exact opposite was the case. The women who followed the traditional multi-set (MS) protocol lost significantly more body fat than their peers in the metabolically more demanding tri-set (TS) group.

The assumption that the multi-set training would (on average!) be the better mass builder, on the other hand, was right. Accordingly, the changes in body fat percentage (not shown in Figure 1) were even more pronounced than the 4% reduction in absolute fat mass would suggest - getting ripped is after all (Ladies listen up!) about losing fat and building muscle.
A different picture emerges for the strength data, though. Surprisingly, the average strength gains on squat and stiff-legged deadlift (1RM and for reps) was higher in response to the strength-wise allegedly inferior tri-set training.

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Figure 2: Changes in squat & stiff-legged deadlift performance in response to 12-week periodized MS vs. TS training (Garcia. 2014)

Overall, and this is maybe the most important message of the study at hand, none of the inter-group differences reached statistical significance - not because they were not large enough, but rather due to the fact that the eleven female trainees responded very differently to the two training regimen.

"Prior to training, there were no differences between groups in terms of age (P=0 .96), body weight (P=0- 28), fat mass (P=0. 42), fat-free mass (P=0. 09), squat 1RM (P=0 .93), squat repetitions maximum (P=0 -25) and stiff leg deadlift repetitions maximum (P=0. 20). The high responder group increased stiff leg deadlift 1RM by a higher amount (P=0 .007). The percent of increase for high, medium and low responders were 25%, 12% and 6%, respectively."

A closer analysis reveals that there were high (>20% gains), medium (between 10-19%) and low (less than 10% gains) responders in both groups. Due to the small size of the sample, it's thus impossible to determine if there were significant inter-group differences. The averages, on the other hand, suggest that the common saying that moving from one exercise to the next with little rest was the better fat burner and worse muscle builder, is about as flawed as most of the common bodybuilding myths.
References:

• Garcia, Paula et al. "Comparison between the multiple-set plus 2 weeks of tri-set and traditional multiple-set method on strength and body composition in trained women: a pilot study." Clin Physiol Funct Imaging (2014). Ahead of print.
• Prestes, Jonato, et al. "Comparison between linear and daily undulating periodized resistance training to increase strength." The Journal of Strength & Conditioning Research 23.9 (2009): 2437-2442.
• Uchida, Marco Carlos, et al. "Effects of different resistance training protocols over the morphofunctional, hormonal and immunological parameters." Revista Brasileira de Medicina do Esporte 12.1 (2006): 21-26.