Which body part is most stubborn to muscle growth?
Your calves, right? For most people they are.
However, calves are often trained at the end of a workout and with much lower volume than other muscle groups.
So perhaps your lack of calf masculature can be attributed to you half assing your calf training.
Researchers aimed to study the effect of a high volume calf workout on the soleus muscle.
Eight recreationally active males were recruited. Each subject completed three separate unilateral calf exercises:
- standing calf press
- bent-knee calf raise
- seated calf press
Each exercise consisted of four sets of 15 repetitions with a load that could be performed ~15 times. Two minutes of rest were given between sets and five minutes between exercises. The non-exercise leg was used to compare results with.
As expected, fractional synthetic rate (FSR), a measurement of muscle protein synthesis, was higher in the exercised leg compared to the non-exercise leg.
In addition, the researchers also compared the exercised calf muscle to other muscle groups that underwent exercise training in earlier studies.
They found that the increase in muscle protein synthesis was much lower in the calf muscle. The rate of calf muscle protein synthesis at rest was not different from other muscles.
The researchers suggest that the muscle fiber types of the calf might explain its poor response to exercise. The soleus is comprised primarily of slow (type I) muscle fibers. Earlier studies suggest that slow muscle fibers are less responsive than the fast (type II) muscle fibers.
They note that the gastrocnemius, the other major calf muscle, has relatively more fast II muscle fibers and might respond better to resistance exercise than the soleus.
They also speculate about an alternative explanation. The calf muscles are highly active during normal activities of daily living such as walking. Therefore, they could be considered to be chronically trained, and consequently less responsive to a training stimuli.
The researchers conclude that calves respond poorly to resistance exercise.