swing those arms!

[monk]

If you've ever trained with me, you've heard me say over and over (other than lean forward) "SWING YOUR ARMS!" i have always been a fan of, and will every single time, tell you to use the full extension of your arm swing. swing both of your hands all the way (comfortably) behind you. as you swing your arms forward- don't bend at the elbows, keep them straight (other than the very slight natural bend that comes from remaining relaxed), don't tense up, and then reach out fully in front of you. this works amazingly to carry you upward and forward. the pendulum effect will carry your upper body weight making the explosive push with your legs even more powerful. http://www.myphysicslab.com/pendulum1.html

with this information, i figured that if i had added weight at bottom of my pendulums, i'd get more force in the direction i want to go, so i got wrist weights-- just one pound on each hand (nearly 2% of my body weight). this maximizes the full extension of the arms and also keeps you from pulling back too soon; continuity in the swing is essential. in a regular broad jump, i was able to get inches farther. it was noticeably easier to achieve that extra distance. in a stair leap, for example at kezar stadium, i could exert a lot of effort (without weights) to jump to the fourth stair. with the weights, it was much easier.

i'm not saying to train or do parkour with weights on your wrists. they are training wheels and they are cheating. so, i'm only saying that they help you realize the importance of maximizing the power of a good arm swing-- laterally and vertically.

[Bay Area Parkour]

Arms after been swung...

Now please consider the angles of the whole projection.

[Philosofist]

@SafeNSure LOL!!!!!!!....lol....

Finally an explanation to my now not so weird habit! Thank you Jodie!

[N_o_F_l_o]

good stuff/

[Bay Area Parkour]

...indeed, pretty telling:

[Nmity]

I couldn't agree with you more mate- Part of the reason that it was so easy for me to switch from volleyball to parkour is because a lot of the same techniques used in volleyball can be used to augment one's parkour ability.
The swing did just that--
See 0:28 - 0:29
His arms go right back, just what you're talking about.
http://www.youtube.com/watch?v=gvatX7kjkIc&feature=related

[SafeNSure]

...yeah ...Swingers Rule!
Lol...

(oh, no... wait... wrong forum... LOL!)
:D

[Seng]

I think the same thing goes for leg swing. In a thief (aka outside foot lazy) vault or speed vault, while powering off one foot one can modulate speed distance with the leg in the air. When climbing/muscling over a wall, throwing a leg upward and close to the chest can get that extra inch or two to rotate over the top.

With the arm swing, I think timing can also help maximize usefulness of the swing. Starting the swing too early and it decreases the momentum of your run up. Copying technique from nordic skiing, I think the coordination of both arms swinging forward show be just one arm quickly changing cadence to match the opposite arm already in it's natural swing during a stride. Hard to explain in text alone so ask me in person, or you can see it in this video at 0:18 (very quick and natural, as it should be). Also notice that after that point, he coordinates his arm swing with his kick before using his poles as propulsion, not unlike split foot take-off to powering through with the arms in a kong.

[Koalapuff]

I love that in Jodie's world, wearing an extra 2 pounds of weight while exercising is considered "cheating" HAHA!

[Deejay]

You are a genius - end of discussion!