09/10/2026
Same exercise. Same time per rep. Different response from the body.
We often talk about lifting slower, controlling the movement, or increasing time under tension.
But does it matter which part of the movement we slow down?
That’s exactly what caught my attention in this study.
Researchers compared different lifting tempos and found something interesting.
When participants slowed down the concentric phase (lifting), they experienced higher lactate and cortisol responses compared with slowing down the eccentric phase (lowering).
At the same time, all three slow-tempo conditions increased growth hormone, free testosterone, and epinephrine.
So, does that mean one tempo is better than the other?
Not necessarily.
Higher hormone levels immediately after exercise don’t automatically translate into better muscle growth. And lower cortisol doesn’t automatically mean a better training session.
This was a small study involving just nine men, measuring immediate physiological responses rather than long-term adaptations.
But it raises an interesting point.
Two movements can look almost identical from the outside while creating different responses inside the body.
That’s why I find exercise science fascinating. The more we understand how the body responds to training, the more thoughtful we can be about how we train.
Not every finding gives us a definitive answer. Sometimes it simply helps us ask better questions.
📖 Goto et al. (2009) — Hormonal and metabolic responses to slow movement resistance exercise.
PMID: 19430944
