The causes of muscle stiffness and cramps range from the minor to the serious, from those mostly under your control to those originating in outside elements.
There are a host of diseases and illnesses which may cause temporary or repetetive muscle cramps and feelings of stiffness and pain.
Everything from the common flu and fever, to more serious illnesses like fibromyalgia, Parkinson, Huntington disease, and other rare conditions.
Certain insect bits and allergies may also have this kind of effect on an unsuspecting person so it may be worthwhile to examine the stiff area for bites and marks if the stiffness persists.
However, most of the times, the causes of stiff muscles are those completely under your control and may be prevented or avoided.
Making sure to do stretching exercises and a proper dynamic warm up before any workout or sporting activity can help maintain a good muscle flexibility and reduce risk of cramps and injuries.
Lack of regular exercise and then engaging in a weekend sporting activity may also lead to stiffness as your muscles aren't accustomed to tension and strain.
The key is to keep up a regular routine of exercising to avoid "surprising" your muscles.
Repetetive movement may also lead to stiffness as well as lack of movement for too long.
Usually, muscle stiffness requires nothing more than a good massage and some quality rest to pass on its own without long term effect.
However, if you suffer from repeated bouts of stiffness you should consult a doctor and make sure to include regular stretching exercises in your daily routine.
The more fit you are, in moderation, the less likely you are to experience stiff muscles and those awfully painful cramps and Charlie Horses.