Re: Is it ever faster to dive instead of run to an object (i.e. first base)?

Diving is advantageous in some circumstances in sports.  The advantage diving provides can be strategic based on the rules of the game or it can be related to performance in which performing the feat may be impossible in any other way.

An example of rules based diving is to dive (or slide) when stealing second or third base because if the runner over runs the base he can be tagged out or if he runs without sliding he must slow down to stop at the base. Also, sliding or diving can be useful in avoiding the tag of the fielder with the ball. 

An example of performance advantage is diving over the top of the lineman on short yardage in football.  In this case, for a good jumper it may be easier to go airborne as opposed to trying to shove opponents and teammates out of the way.

Some athletes can cover more ground more quickly by leaping or diving, but this is an all or nothing commitment.  Once the leap or the dive has been performed there is a recovery time to regain one's feet and orientation.  However,  leaping/diving may give the player the opportunity to make a play that could not be performed otherwise because of body position.  And for some athletic feats in which a follow up move is not required (like diving into the endzone, crossing the finishline, diving into home

For example, an infielder dives to get her glove on a sharply hit ground ball.  The player leaves her feet to make the play on the ball.  The decision to dive is based on experience or "instinct" that tells the player that running all the way to field the ball will not work because she will be running so hard that she will not be able to field the ball in proper body position to get the ball and then make a throw because  flat out top speed will be required.   This seems like the proper situation to dive to get to the ball.

I believe diving into first base is based on a similar instinct.  Most ball players have experienced running to first base at top speed and upon getting to the base the batter's stride is messed up.  In a perfect situation the batter steps on first base in perfect stride with the foot that hits the base fully extended so that no effort or speed is wasted making a correction to step on the base.  By diving into the base the batter makes the all or nothing commitment and does not have to make the running stride correction.  If performed properly the hands will hit first base before the player would have stepped on the base at normal run with a stride correction provided no sliding on the ground before the base occurs.  Sliding is basically letting the friction of the ground with the players leg slow the player down, while diving the friction works between the hands and arms first and then the rest of body once it hits the ground.

In general, diving gets the player to the base faster than sliding but puts the player in a more vulnerable position for injury.
Diving can be dangerous and lead to injury -- especially when diving into a base in baseball.  If the base does not move, the player's hands, wrists, elbows, and shoulders could wind up being injured.   Part of why homeplate is low and mostly flat is to prevent injuries to players sliding into home.  Because a batter can run past first base without penalty of being tagged out (provided she does not turn toward second base) most coaches would rather the batter "run through first base" instead of diving.  And sliding into first base is rarely a good idea.

Sincerely,

Tom "Base Ghost" Cull