Pullups.
Protocol = 6 reps done relatively slowly, do some of the other exercises, then return for one more set of 6 reps. If you’re a runner and you’re gonna do pull-ups on a bar and/or curls with dumbells you should consider doing them in a forearm position where your palms face each other.
In kinesiology terms, your palms shouldn’t be supinated [palms up] or pronated [palms down], they should be in mid-position.
Purpose being that the training stimulus is directed as much or more to the brachio-radialis muscle [forearm muscle] than to the biceps.
.
The arm swing during the running stride should involve a relatively large gap of space between the forearm and upper arm at all times. That gap should never be small or non-existent at any time.
In running biomechanics [physics applied to running] terms, you should maintain a long lever arm.
.
This increases the upper body’s ability to counter the “angular momentum” [twisting forces around a vertical axis through the body] created by the forward and backward movement of the much heavier legs.
.
It also increases the runners ability to send more energy into the ground during the drive phase [forward propulsion] of the running stride.
Newton’s laws of motion, taking advantage of action-reaction [for every action there is an opposite and equal reaction] concept in the “ground reaction forces” that are a huge part of running biomechanics.
.

TheETG optimal running form —–
http://theetgtrackclub.com/documents/TheETGrunningformMasterOfSport.pdf
.
TheETG training program —–
http://theetgtrackclub.com/documents/TheETGMasterOfSport.pdf