All them, but the legs and buttocks do most of the work in cycling.
Here are the groups, (quadricep) this straightens the leg,(hamstrings)this muscle bends the leg,(gluteals) these are your buttocks and the(gastrocnemis and soleus) are your calf muscles.
If you're riding well hunched over you'll bring your abdominals and back muscles into play to some degree as well. Riding out of the saddle will engage arms and shoulders too.
all muscle groups are used.
Chin-ups, just as most exercises use a primary & secondary muscle group. The primary muscle group would be the back (or latissimus dorsi). This is what helps to give that "V" - shape in the torso area. (along with slimming down the torso area, of course) The secondary muscle group would be the biceps. Depending on your grip position, you can focus either more on your "lats", or arms.
Any sport that includes running/walking/cycling will use your calf muscles. Riding a bike every day is also a good way to strengthen your calves.
The use of stationary exercise bicycles in a group is usually referred to as Spinning.
Chin-ups, just as most exercises use a primary & secondary muscle group. The primary muscle group would be the back (or latissimus dorsi). This is what helps to give that "V" - shape in the torso area. (along with slimming down the torso area, of course) The secondary muscle group would be the biceps. Depending on your grip position, you can focus either more on your "lats", or arms.
The eyes' muscle group is the orbicularis oculi
It depends on the cyclist. Many people cycling as a form of transportation, some use cycling as recreation, some people cycle for fitness, while a small group cycle competitively in organized races.
athletes that aren't very good.
The Orbicularis oris muscle. It is sometimes known as the kissing muscle because it is used to pucker the lips.
My bet would be the hot water heater cycling water through
To effectively communicate with your cycling group using a walkie talkie during rides, ensure clear line of sight, use clear and concise messages, establish a designated channel, use proper etiquette like waiting for pauses to speak, and test the walkie talkies before the ride.
He/she would use flexibility training to increase the flex a muscle can give. This would protect against cramps and strains in extreme position, because the muscle and ligaments would be use to the awkward and sometimes excessive strain.