The bike is generally uses mainly your quads, so I am surprised that it is hurting your hamstrings. As a rule, if it hurts, don't do it.

Factors which contribute to hamstring injuries are a lack of flexibility and poor strength of the hamstring muscles. Also, when the hamstrings become fatigued or tired they are more susceptible to injuries.

The best preventative measures involve a consistent program of both stretching and strengthening exercises. Increased flexibility will contribute greatly to the ability of the hamstring muscles to resist strains and injury. To follow are two very effective and very safe hamstring stretches.

(1) Simply kneel down on one knee and place your other leg straight out in front with your heel on the ground. Keep your back straight. Make sure your toes are pointing straight up and gently reach towards your toes with one hand. Use your other arm for balance. Hold this stretch for about 20 to 30 seconds and repeat at least 2 to 3 times.


(2) Simply stand with one foot raised onto a chair, fence railing or similar object. Keep your raised leg slightly bent, with your toes on the edge of the chair. Let your heal drop off the edge of the chair. Keep your back straight and gently move your chest towards your raised leg. As above, hold this stretch for about 20 to 30 seconds and repeat at least 2 to 3 times.


Warming up correctly will also contribute greatly to reducing the likelihood of a hamstring injury, and don't just stretch before you exercise. Warming up thoroughly prior to any activity that stresses the hamstring group may prevent hamstring strain. The warm-up should include range of motion work and stretching. Full-speed sprinting or maximal-effort jumping should always be preceded by reduced efforts at these activities.

Surfaces such as tracks, jumping approaches, courts, and floors should be examined to assure they are firm, appropriately resilient, and not slippery or wet.

Maintenance of flexibility of the leg and full range of motion at the knee and hip is requisite for preventing hamstring injuries
The best way to prevent reinjury is to meet all criteria for a full return to activity.

Strengthening the hamstring muscles will also reduce the incidence of subsequent strains. As a rule, the hamstrings should be no less than one third as strong as the quadriceps muscle group, which forms the front of the thigh. For instance, if the quadriceps can raise 100 pounds during knee extension (leg extension machine), the hamstrings should be able to raise no less that 33 pounds during knee flexion (leg curl machine).

Use a machine designed for exercising the hamstring muscle group. Lie face down on the machine with the resistance bar/pads at the ankles . Raise the resistance with both legs to full travel of the machine, or until first pain intervenes.

Slowly lower the resistance with the injured leg only. Begin with light resistance and increase the resistance at subsequent exercise sessions. Repeat 10 times.

For symmetrical strength development, this exercise should also be done with the uninjured leg.