How heavy slow resistance training is structured
Heavy slow resistance (HSR) is a tendon-loading approach that uses relatively heavy loads moved through a deliberately slow tempo, often around three seconds in each of the concentric and eccentric phases for a total near six seconds per repetition. Sets are typically in a low repetition range (around six to fifteen, often progressing toward the heavier end) and performed a few times per week, rather than the high daily volume of classic eccentric heel-drop programmes.
Both the lifting and lowering phases are loaded, so the protocol is not eccentric-only. It is commonly applied to patellar and Achilles tendinopathy.
How it compares with eccentric-only work
Trials comparing HSR with eccentric protocols have generally found similar improvements in pain and function, with HSR often requiring less total weekly time and being reported as well tolerated. That favorable time profile is a practical reason it is offered as an alternative. The evidence base is modest in size, and individual response differs.
Choice of protocol depends on the tendon, the stage, and the individual. This is general educational information, not medical advice; a qualified clinician should guide diagnosis, load selection and progression.