Two Sets Are Enough to Get Strong, Scientists Find

Athletes and gym-goers spending hours grinding through endless sets may be wasting their time, according to new research from Florida Atlantic University.

The comprehensive analysis of dozens of studies reveals that meaningful strength gains plateau after just two focused sets per session, while muscle growth peaks around eleven sets. The findings challenge the “more is always better” mentality that dominates many training programs and suggest that strategic, shorter workouts can deliver comparable results to marathon gym sessions. For time-pressed individuals, the research offers a science-backed path to efficient fitness gains without sacrificing precious hours to diminishing returns.

The meta-analysis, published as a preprint in SportRxiv, examined data from 67 studies involving over 2,000 participants to determine exactly where the point of diminishing returns begins for both strength and muscle building.

The Two-Set Sweet Spot

When it comes to building raw strength, the researchers discovered something remarkable: benefits level off dramatically after just two “direct” sets per session. Direct sets are those that specifically target the movement or muscle being tested—like bench press sets when measuring bench press strength.

“Rather than simply piling on more sets in a single workout, people aiming for strength gains may get more out of increasing training frequency – choosing shorter, more frequent sessions instead,” said Jacob F. Remmert, lead author and Ph.D. candidate in the Department of Exercise Science and Health Promotion at FAU.

This finding aligns with mounting evidence that strength development follows different rules than muscle growth. The researchers found that even very low training volumes, when paired with heavy loads and consistent weekly frequency, can lead to substantial improvements in strength.

The implications are profound for beginners especially. Those new to strength training can make meaningful progress with just one to two high-intensity sets per session, particularly when lifting loads above 80% of their one-rep maximum.

Key Research Findings:

• Strength gains plateau after approximately 2 direct sets per session
• Muscle growth peaks around 11 fractional sets per session
• Study analyzed data from 2,058 participants across 67 studies
• Benefits show diminishing returns quickly for both outcomes

The Science Behind Set Counting

One of the study’s most important contributions lies in how researchers categorized different types of training sets. Rather than treating all sets equally, they distinguished between “direct,” “fractional,” and “total” sets based on how specifically each exercise targeted the measured outcome.

“It’s important to understand the difference between direct and fractional sets,” Remmert explained. “Direct sets are those that specifically target the muscle or movement being tested. As an example, for increasing bench press strength: counting direct sets means only counting sets of bench press specifically, whereas counting fractional sets would also include indirect work – like triceps extensions, which still engage muscles involved in the bench press, but not as the prime mover. The sets that train the movement directly are what move the needle the most when you’re trying to get stronger in that specific lift.”

This distinction proved crucial for understanding training responses. For strength gains, only movements that directly matched the tested exercise provided maximum benefit. For muscle growth, the picture was more nuanced, with “fractional” sets (where indirect exercises counted as half a direct set) providing the best model for predicting results.

Beyond the Press Release: The PUOS Revelation

While initial coverage focused on the basic findings, the study introduces a sophisticated concept that wasn’t emphasized in early reports: the Point of Undetectable Outcome Superiority, or PUOS. This represents the precise threshold where adding more training volume becomes statistically meaningless for individual-level improvements.

The PUOS calculations reveal that beyond 2 direct sets for strength and 11 fractional sets for muscle growth, additional work yields such small, inconsistent benefits that they fall below the smallest detectable effect size. This isn’t just about diminishing returns—it’s about identifying the exact point where more work becomes essentially worthless for measurable progress.

This mathematical precision in determining training thresholds represents a significant advance in exercise science methodology, providing practitioners with specific, evidence-based targets rather than vague guidelines.

The Muscle Growth Story

For those focused on building muscle size, the researchers found a more forgiving dose-response relationship. Benefits continued to accrue up to around 11 fractional sets per session, though with diminishing returns as volume increased.

“Because of the diminishing returns and greater uncertainty of outcomes as volume increases, it’s important to weigh the small potential benefits of additional volume against the extra demands on time and recovery,” Remmert noted. “To be fair, some people value squeezing every last drop of muscle growth out of their program no matter the cost; for them, experimenting with higher volumes makes sense, so long as they keep a close eye on recovery.”

The muscle-building findings suggest more flexibility for those willing to invest additional time and effort. However, the researchers caution that benefits beyond 11 sets per session tend to be small and inconsistent, requiring careful consideration of the cost-benefit trade-off.

What’s particularly striking is how the relationship between sets and muscle growth follows a logarithmic pattern rather than a linear one. The biggest gains come from the first few sets, with each additional set contributing progressively smaller improvements.

Rethinking Training Frequency

The research has profound implications for how we structure workout schedules. If strength gains plateau after just two sets per session, the logical strategy becomes spreading training across more frequent, shorter sessions rather than cramming volume into marathon workouts.

This approach aligns with emerging evidence about muscle protein synthesis patterns. Since the muscle-building response to exercise peaks and then declines within 24-48 hours, more frequent stimulus may prove superior to less frequent, high-volume sessions.

For busy professionals, this represents a paradigm shift. Instead of dedicating entire evenings to gym sessions, optimal results might come from brief, focused workouts spread throughout the week.

The Practical Translation

“Our findings show that you don’t need lengthy gym sessions to get stronger or build muscle,” said senior author Michael C. Zourdos, Ph.D., chair and professor of the FAU Department of Exercise Science and Health Promotion. “There’s a tipping point where the benefit of doing more becomes very questionable – and in some cases, it may even work against you when considering fatigue, time and so on. This challenges the common assumption that more volume always equals more gains.”

The research validates what many time-pressed individuals have suspected: efficient training can compete with time-intensive approaches. For strength development specifically, the data suggests that a program featuring low per-session volumes with emphasis on frequency—approximately 2-3 sessions per week—may optimize results.

However, the researchers emphasize that these findings apply primarily to short-to-moderate term adaptations. Long-term strength development may follow different patterns, and individual responses will always vary.

The Volume-Frequency Puzzle

One of the study’s most intriguing findings involves the complex relationship between training volume and frequency. While the research provides clear guidelines for per-session volume, the optimal way to distribute training across the week remains an area requiring further investigation.

The mathematical precision of the PUOS calculations suggests that the sweet spot for most people lies somewhere around 2-3 focused training sessions per week, with each session containing the minimal effective dose of sets. This approach maximizes the muscle protein synthesis response while avoiding the accumulating fatigue that comes with excessive volume.

Why does this pattern emerge? The researchers point to fundamental physiological limitations. Muscle protein synthesis elevates for roughly 24-48 hours post-exercise before returning to baseline. Attempting to stack additional sets beyond the effective threshold doesn’t extend this window—it simply wastes energy and recovery capacity.

The Implications for Real People

For the average person juggling work, family, and fitness goals, these findings offer a liberating message: you can achieve meaningful results without living at the gym. The research suggests that two high-quality strength sets performed consistently will outperform sporadic high-volume sessions.

This principle extends beyond individual workouts to long-term adherence. Programs that demand excessive time commitments often lead to burnout and inconsistency. By contrast, efficient protocols built around the PUOS thresholds may prove more sustainable over months and years.

The study also highlights the importance of progressive overload and consistency over sheer volume. Whether you’re performing two sets or twenty, the quality of effort and systematic progression matter more than the raw number of repetitions completed.

As Zourdos concluded, “Instead, we found that diminishing returns set in very quickly, and a low dose of training for strength or a moderate dose of training for muscle growth seem to deliver the most efficient results. For busy people, that’s great news: you can train smarter, not longer, and still see real progress.”