Breakthrough approach for boosting muscle growth during workouts

When you're lifting weights or engaging in resistance training, you might wonder how close you need to push yourself to failure – the point where you can't complete another rep – to maximize your results.

Researchers from Florida Atlantic University, along with collaborators, set out to understand how training near failure impacts muscle growth and strength. They examined whether there's a linear or non-linear pattern in the relationship between the distance from failure, measured by repetitions in reserve (RIR), and changes in muscle strength and size.

The study primarily focused on how training near failure affects the primary muscles used during an exercise. For example, during leg presses, the emphasis was on the quadriceps. Researchers estimated the number of repetitions in reserve, which indicates how many more reps you could have done before reaching failure.

They gathered data from 55 studies and performed extensive statistical analyses to determine how various levels of reps in reserve influenced strength and muscle growth.

The results, published in the journal Sports Medicine, revealed that training close to failure doesn't significantly impact strength gains. Whether you stop far from failure or very close to it, your strength improvement remains similar. However, muscle size, or hypertrophy, does benefit from training closer to failure. The closer you are to failure when you stop your sets, the more muscle growth you tend to see.

"If you’re aiming for muscle growth, training closer to failure might be more effective. It doesn’t matter if you adjust training volume by changing sets or reps; the relationship between how close you train to failure and muscle growth remains the same," said Michael C. Zourdos, Ph.D., senior author and professor and chair of the Department of Exercise Science and Health Promotion within FAU’s Charles E. Schmidt College of Science. "For strength, how close you push to failure doesn’t seem to matter as much."

The researchers suggest that if your goal is to build muscle, you should work within a range of 0-5 reps short of failure to optimize growth while minimizing injury risk. For strength training, it's better to focus on heavier loads instead of pushing your muscles to failure. They recommend stopping about 3-5 reps short of failure to avoid additional physical strain.

"Training closer to failure enhances the accuracy of self-reported repetitions in reserve," said Zac P. Robinson, Ph.D., first author and a Ph.D. graduate of FAU’s Department of Exercise Science and Health Promotion. "When people estimate how many reps they have left, this perception influences the weights they choose. If the estimation is off, they might use lighter weights than needed, which could limit strength gains."

"On the flip side, our meta-analysis shows that training closer to failure also leads to greater muscle growth. So, for the average individual, training close to failure may be the best option – as it seems to improve the accuracy of our perception of effort as well as gains in muscle size," he continued.

These findings highlight the challenges of training close to failure, which can be tough and harder to recover from, potentially impacting long-term performance negatively. Additionally, training closer to failure might better simulate the conditions of a maximal strength test, which is commonly used in strength training programs, rehabilitation, and athletic performance assessments to gauge an individual’s strength capabilities and track progress over time.

"As the load increases, motor patterns change, which means performing sets closer to failure can more closely mimic the demands of max strength assessments," said Zourdos. "This approach aligns with the principle of specificity by exposing you to similar motor patterns and psychological challenges. Moreover, training near failure may also improve psychological factors like visualization, which are important for achieving maximal strength."

The results of this study could guide future research and provide valuable insights for trainers on how proximity to failure affects muscle growth and strength. However, the exact numerical relationship between training close to failure and strength gain remains unclear, and future studies should be designed to explore these effects in larger samples.

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

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