I'm will be running my first ultra marathon this summer and am looking for a running pack for the event. Is this pack great for running or are there better designs for long distances?

Tech Specs:

Material:

70D x 100D Nylon shadow check, 160D x 330D Nylon shadow box, stretch woven nylon with Lycra 

Volume:

(S/M) 600 cu in, (M/L) 700 cu in 

Waist-Belt:

yes 

Waist-Belt Type:

harness hip-belt 

Pockets:

1 front zip, 2 waist-belt, 2 harness energy gel 

Weight:

(S/M) 1 lb 15 oz, (M/L) 1 lb 7 oz 

Recommended Use:

hiking, mountain biking, trail running 

Manufacturer Warranty:

lifetime