Target Muscle/s: Soleus (lower calf)
Sets & Reps: 12 repetitions (each leg)
Tempo: Lift for 1 (second), hold for 2, lower for 3
Frequency: Twice a week strength training program
Whether for performance gains or as part of Achilles tendinopathy rehabilitation, strengthening of the soleus muscle can be a highly beneficial addition to any runner’s strength training program. Despite popular belief, the soleus muscle of the calf complex actually contributes more to force production during running than the gastrocnemius, because during running it deals with the loads whilst the knee is bent. Research suggests the soleus produces up to 50% of total vertical support; to put that into perspective, whilst the gastrocnemius produces forces of about three times your body weight during running, the soleus produces around eight times.
To target the soleus when you do your calf raises, studies have shown that your knee needs to be bent to at least 80 degrees. The most practical way of achieving this is performing the calf raises whilst seated, as trying to maintain a deep bend in the knee whilst standing can put unnecessary strain on the knee. Bear in mind that whatever version of the exercise you are doing, the weight you choose needs to be heavy enough to cause failure (total fatigue) by either 30 seconds or 12 repetitions (see versions below). Only then will your body to be stimulated enough to adapt, i.e. get stronger. Your goal is to increase the weight over time as you get stronger.
- The ISOMETRIC version of this exercise involves you now holding this right foot tip toe position for up to 30 seconds. The weight needs to be heavy enough to allow no more than 30 seconds. Once you get stronger and can do over 30 seconds you will need to add more weight.
- The ECCENTRIC version of this exercise involves you holding this right foot tip toe position for 2 seconds and then slowly lowering the heel back down over the edge of the step during 3 seconds. Repeat the movement by using two feet to lift the weight up, one foot to hold and lower, and so on. The weight needs to be heavy enough to allow no more than 12 repetitions. Once you get stronger and can do over 12 repetitions, you will need to add more weight.
- The CONCENTRIC version of this exercise involves you using just one foot to lift and lower the weight. Keep the tempo slow and controlled and use enough weight to allow no more than 12 repetitions. Once you get stronger and can do over 12 repetitions, you will need to add more weight.
When To Take The Step Away
In cases of Insertional Achilles Tendinopathy where the aggravated part of the tendon is close to the attachment point on the heel, using a step can potentially delay recovery. Dropping the heel over the edge of the step puts the tendon under both tension (stretch sensation) and compression as it is pushed against the heel bone. This is normally fine but if the tendon is in an irritated state then this combination of tension and compression can potentially sensitise the system further, and delay recovery. In such cases, rehabilitation may involve removing the step so that the heel only lowers to floor level, eliminating combined tension and compression until irritation has reduced. Traditional static stretching may also be temporarily removed for the same reason, along with deep squats and lunges. If in doubt, get assessed by an injury specialist so they can select the appropriate exercise for you.
Matt Phillips is a Running Injury Specialist & Video Gait Analyst at StrideUK & Studio57clinic in Sussex. Follow Matt on Twitter.