We recently headed into the hills for some training and thought. This would be cool to make a guide for athletes to combine 'cross training' and running.
Here is the 'boat pose'. Find a nice seat, kick up your feet and hold it. 30 Seconds is great. One minute is INSANE!
Triceps dips. A rock 18" tall works great. Lower to 90 degrees and return. 
Find a good rock 10-20 pounds. Lift with your legs to  your groin. Raise to your chest and then over your head. Maintain a strong core. No "wiggles".
Leg dips. Balance on one leg drop other off of a rock. Can you go 6"? Maybe 12" or even until your dropped knee is level with your foot! If so, You are a 'rock star'!
Rock jumps!  Find a good "solid" rock, 6-12" tall.
And jump over and back.
Rock Jumps. A 'solid' rock 12-18" works great.
Yes, I am screwing around, but 'Planking' is good exercise too!
And rock 'steps'... Up down, alternate legs.
5-10 pound rock.
A solid core.
A slow, 360 degree rotation.
And reverse...
Push-ups and a good calf stretch too.
Plank twists. Knee towards opposite elbow, return, switch legs and repeat.