In London, the marathon training season is reaching its peak. As training runs get longer, injuries related to fatigue and muscle weakness increase - and we see more runners struggling to keep up their training program. Injuries such as shin splints, achilles pain, and calf injuries are so common as the runs get longer.
One possible cause of these fatigue and impact injuries is inadequate strength in the muscles that matter. One of these is the calf muscle, which pushes us forward every step. We have found it really helpful to know the normal values for heel raise exercise, giving an indication of calf strength and endurance. We can test our runners, and get a good idea if their muscle strength is where it should be according to their age and gender.
This is such an easy test to perform on yourself. Stand on a slightly sloping surface (10% incline was used in the study below). Standing on one leg, rise up onto your toes as high as you can, then lower down. Straight away, rise up again. Repeat until you are unable to perform a full calf raise - you have reached your fatigue level.
Herbert-Losier et al (2017) studied over 500 healthy active people and found the following norms for male & female age groups:
20-29yrs: Males 37 reps, Females 30 reps
30-39yrs: Males 32, Females 27
40-49yrs: Males 28, Females 24
50-59yrs: Males 23, Females 21
60-69yrs: Males 19, Females, 19
70-79yrs: Males 14, Females 16
80-89yrs: Males 10, Females 13
So give it a try, and see how you measure up.
Reference : Physiotherapy. 2017 Dec;103(4):446-452