SST methods, or Slow Strength Training methods, improve muscle tension and growth primarily by increasing the time muscles spend under tension during each repetition. When you perform exercises slowly, especially during the eccentric (muscle-lengthening) phase, your muscles experience greater mechanical tension. This tension is a key factor that stimulates muscle fibers to grow and adapt. For example, slowing down the eccentric phase to about 3 to 5 seconds has been shown to significantly boost muscle protein synthesis, which is essential for muscle growth[1].
By controlling the tempo of your lifts, you also improve the mind-muscle connection. This means you focus more on the muscle being worked rather than relying on momentum, which leads to better muscle fiber recruitment and more effective training. Slow, deliberate movements reduce the risk of injury because they eliminate bouncing or jerking motions that can strain joints and connective tissues. Additionally, SST helps reveal weak points in your range of motion, allowing you to target and strengthen those specific areas[1].
Research and expert advice suggest that slow, controlled repetitions are more effective for long-term muscle growth and injury prevention than fast, explosive lifting. Explosive lifting does not necessarily increase hypertrophy more than controlled lifting and carries a higher risk of connective tissue injury. Therefore, SST methods provide a safer and more efficient way to build muscle and strength over time[2].
Sources
https://fitnessrec.com/articles/exercise-tempo-for-muscle-growth-master-time-under-tension-and-strength-gains
https://www.youtube.com/watch?v=iDKQXORJcZE
