The ECB fast bowling directives have changed following a two-year consultation process. The outcome is that bowlers up to under-15 level are now able to bowl longer spells and more overs in a day.

Under the new guidelines bowlers at under-16 and under-17 level are now permitted to bowl an extra over per spell, but those in the under-18 and under-19 category have had the total number of overs they can deliver per day reduced from 21 to 18.

These guidelines will come into effect for the start of the 2010 season.

The fast bowling guidelines are designed to raise awareness of the need to nurture and protect young fast bowlers through their formative years. Research has shown that fast bowlers are by far the most likely players to be missing playing and training time due to injury.

For the purpose of these guidelines a fast bowler should be defined as a bowler to whom a wicket keeper in the same age group would in normal circumstances stand back to take the ball

Kevin Shine, ECB lead fast bowling coach, said: "The elite fast bowling group has been researching injury prevention, performance enhancement and workloads for the past four years.

"The new recommendations mean youngsters under the age of 15 can now bowl an additional over in a spell and two overs more in a day. These figures are over and above the original directives.

"It is clear that our young bowlers need to bowl more so that they can develop match winning abilities and habits and I look forward to the revised directives giving individual fast bowlers and teams more of a chance to play match winning cricket"

The results included input from clubs, county boards, ECB elite performance group, which includes, ESCA, ECB performance, ECB development, England elite player development, ECB operations, and HMC schools.