Baraka_Guru

If it's the pullovers that have the most effect, I imagine it's because your triceps are the weakest link. A dumbbell press is a complex movement requiring support from shoulders and triceps. If either of these are too weak, your chest won't be challenged enough because, as you say, they will hurt, leaving your chest untrained. When you train, you should be sure to maximize the load on all areas. As I mentioned, it's difficult to focus on only one area. For example, if you are certain that you're maxing your workouts on shoulders, chest, back, triceps, and biceps, you can be sure to maximize the benefits on all accounts. I'll say it again: the body thrives on synergy.

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Knowing that death is certain and that the time of death is uncertain, what's the most important thing?
—Bhikkhuni Pema Chödrön

Humankind cannot bear very much reality.
—From "Burnt Norton," Four Quartets (1936), T. S. Eliot