If you’re a team sport athlete already competing in your season, a study published in The Journal of Sports Medicine and Physical Fitness might be of interest to you. The findings will give you some idea of the performance enhancements that are possible with a short duration uphill sprint training program.
Researchers had 14 college aged male soccer players run a 3 KM time trial. They also performed agility and intermittent recovery tests. Half of these subjects were assigned to an experimental protocol where they ran 10 sets of 10-second sprints up a 7% incline with a minute of rest between sets. These intervals were added to their regular in-season training twice weekly for 6 weeks.
Compared to measurements taken before starting the uphill sprint program, agility improved by around 3% and there was a 10% average improvement in strength. Time trial performance was around 4% faster after uphill sprints, and oxygen consumption improved by an average of 3%.