i have the same problem with gaining weight. i am 5'10" and 140lbs. my start is actually pretty fast when im in top shape but my top speed and/or speed endurance is lacking.
i looking to gain some weight too. i am taking a year off from competetive track and want to just focus on gaining strength, power and mass. my last maxes were 325 for squat and a mere 170 for power cleans. how can i improve my significant power defecit.
ps. the weird thing is my start is pretty damn fast, but after 50m i fall apart