Hey!!! I’ve been studying about tendon and ligament strength and I understood that tendons get stronger when streched in resistance training (the bottom of the pistol squat, the three of the four quad heads are streched and pressed by the bodyweight as resistance, etc).So I was wondering, how exactly the core muscles (abdominals, obliques, hip flexors, spinae erector) get their tendons trained??? It doesn’t make sense, because I can’t imagine an exercise where they’re streched in a way of training the tendons.
They train exactly the same as other tendons. You progressively overload, they adapt – it’s just the time scale is much longer than muscular adaptation. Also, many muscles around the upper body attach to deep fascia and even to other muscles rather than just to bone, so their way of stretching (per pistols example) might not work the way you think.
But as Robby said, I wouldn’t get too hung up on this aspect unless it’s something you’re studying. Nice to know but just having faith that your body knows what to do, how to do it and will respond to training is enough 😉