Calf stretch:
The calf muscle cramps easily if not properly stretched.  Under stretching or not stretching the calf muscle can also put it at high risk for strain and other injury.  Stretch the muscle as follow:
    *    Stand arm’s length from a wall, extend your arms and place your palms on the wall about shoulder width apart. 
    *    Lean on the wall 
    *    Extend one foot behind you, press the heel down and move the other foot closer to the wall
    *    Lean toward the wall from your hips until you feel a stretch in the calf of the extended leg
    *    Hold your calf stretch for at least 30 seconds on each side
Over time this stretch may begin to feel less and less intense.  When this happens, begin moving your extended foot back further.

Stress fracture of the tibia:
The tibia or shin bone is the most vulnerable of all bones to stress fractures in distance runners, accounting for more than half the total number of stress fractures.

The injury occurs suddenly with no external violence involved.  Extreme tenderness is felt, localized to the bone at one or more of just below the knee, at the junction of the lower third and upper two thirds of the tibia.  The injury heals completely within two to three months of complete rest.

Training errors in the form of sudden increase in training load through longer distances, more speed and frequent racing, or a heavy training load for many months, appear to be the major problem.  The bone is subjected to increased load before it is ready to cope with it.

The only recognized treatment is complete rest from running for eight to twelve weeks.  One may obtain relief from the symptoms for this stress fracture by wearing a pneumatic leg brace.  Exercising in water may also speed up the healing process.

Nutrition:
There are three key ingredients to performing at your best in a sporting event: nutrition; sufficient rest; recovery and training.  Many athletes underestimate that nutrition plays the most critical role of all three and tend to put all of their emphasis on training instead.  Nutrition is so vital, and it ultimately will determine how your body will perform in any sporting event.  Eating a well-balanced diet and ensuring you are fuelled up consistently through the week will ensure that your body is receiving the correct ingredients to ensure quality workouts, performance and health benefits.

Eat well balanced foods throughout the week ensuring your glycogen levels are kept topped up, such as complex carbs, plenty of fruit and vegetables and easily digestible proteins.

Fuel up properly in the morning prior to racing.  Have a low GI meal to ensure a balanced and sustainable energy supply.

Avoid stimulants such as sugar rich foods and caffeine prior to an event.