If you want to improve in baseball, football, basketball or hockey, learn to run faster.  To run fast in competitive sports, you have to run fast in practice and lift heavy weights to become stronger.  Run a series of short fast sprints with a short rest between each. Do resistance exercises because stronger muscles drive you forward with more force.
 You can always tell when a coach knows what he or she is doing. This year, one professional basketball team has so many injuries that they had to bring new players
to the team.  No coach should ever require players to run sprints at the end of every practice or lift heavy weights more often than twice a week.  Every time you run fast or lift heavy, your muscles fibers are damaged and feel sore on the next morning, an take at least 48 hours to heal. If you try to run fast or lift heavy when your muscles feel sore, you are at increased risk for tearing them and not being able to play at all. In the preseason, knowledgeable coaches have their players scrimmage hard and run
sprints on one day, and practice plays and take it easy on the next. During the season,they play so often that players should not be asked to do much hard training. 
Training for a Triathalon
People who compete in triathalons have to train for three sports.  To be proficient in a sport, you need to train at great speed in that sport. However, every time you exercise intensely, your muscles are damaged and it takes at least 48 hours for muscles to recover enough to exercise intensely in that sport again. Therefore, athletes in endurance sports set up their training programs so that they train very intensely no more often than every other day.  To increase endurance, you have to perform a long endurance workout, but you can't do it more often than once a week.  10 For a triathalon, athletes have to train for running, cycling and swimming.  Since each sport stresses different muscle groups, it is possible to train intensely in one sport and then on the next day, to train intensely in a different sport.  Running stresses primarily the lower leg, cycling the upper leg, and swimming the upper body. Running causes the most muscle damage and requires the longest recovery periods, so most triathletes run on one day and swim and cycle on the next. A typical training program  includes one fast and one long workout in each sport once a week.  For example, run long on
Sunday, swim fast and cycle easy on Tuesday, run easy on Wednesday, swim long and cycle fast on Thursday, run fast on Friday, and cycle long on Saturday. 

Cross Training Reduces Athletic Injuries

Triathletes are injured only one third as often as marathon runners even though they do far more work, swimming, cycling and running.   Training intelligently for three sports is less likely to injure you than training too hard for one. Training is limited by damage to skeletal muscles. Every time you exercise, your muscles develop small tears with bleeding.  It takes at least 48 hours for muscles to heal from exercise. Each sport stresses a particular group of muscles most.  Marathon runners train every day and stress the same muscles that have not had adequate time to recover from the previous day's workout, so they are at increased risk for injury.    On the other hand, top triathletes train at different sports on consecutive days. Running stresses the lower leg muscles most, cycling stresses the upper leg muscles most and swimming stresses the arms and shoulders most. Triathletes should set up a workout schedule that includes two sports on one day and one on the next.  Of the three sports, running causes the most muscle damage.  Muscles are protected by the water in swimming
and by the rotary pedal motion in cycling.  However, the force of the footstrike in running tears up muscles.  So a knowledgeable triathlete runs on one day and cycles and swims on the next. 
Run Fast to Train for a Marathon
Many runners have the mistaken impression that they have to run a lot of miles to be able to run fast in a marathon or any long race.  Most will find that running too many miles slows them down.  To run fast in races, you have to run very fast in practice.  However, on the day after you run very fast, your muscles will feel sore and if you run fast when your muscles feel sore, you will injure yourself and not be able to run at all.  Take easy workouts until your muscles feel fresh again.  Most competitive runners set up their programs so that they run fast on Tuesdays and Thursdays and longer on Sundays.  The rest of the time they run slowly or not at all.  Interval training helps you to run much faster than you could possibly run continuously.  Your goal is to be able to run repeat intervals with short rests in between on your fast days.  For example, once you are in good shape, on Tuesdays  try to run four half-mile repeats at a very fast pace with a quarter mile jog between each.  If you can run a mile flat out in six minutes, you probably will try to run each half mile repeat in around three minutes and 15 seconds.  On Thursdays, you can try to run eight to 12 repeat quarter miles at close to the same pace of around 90 seconds  each.  On Sundays, try to run briskly for 90-120 minutes. The rest of the time, jog slowly, being careful not to run so much that it interferes with your two fast and one long day each week. 
Longer Strides Make You Run Faster
The only way you can run faster is to take more steps per minute called cadence or take longer strides.  Nancy Hamilton of the University of Northern Iowa videotaped runners at several competitions. She found that faster and younger runners had the same cadence as slower and older runners, but took longer strides.  However, if you ask people to take longer strides, they will run slower because you cannot consciously control your stride length. More than 75 percent of the energy from running is stored in your tendons and while you toe off the ground, the tendons spring back to drive you forward. Trying to take longer strides loses kinetic energy and slows you down.  The only reasonable way to extend your stride is to develop a greater flexibility of the hip and to a lesser degree the ankle, and to do exercises to strengthen the muscles in the back of your legs to propel you forward.  Stretch the quad muscles in the front of your leg and do exercises to increase flexibility of the hip to give you a greater backward ovement of your hip.  Competitive athletes and older exercisers can benefit from leg presses and knee extensions to strengthen their quadriceps muscles.  They should perform sitting toe touches to stretch hamstrings, wall pushups to stretch calf muscles, standing quad stretches to stretch the muscles in the front of the upper legs and hurdler stretches with the legs raised to increase hip flexibility.