How Exercise Works, From Strength and Stiffness to Self-Efficacy

Peter looks at the mechanisms behind exercise. In a trial from his group, high intensity training produced larger strength gains, yet all groups improved equally on the VISA scale and change in MVIC showed almost no relationship with change in pain and function. In the Radovanović study, passive therapy, Alfredson eccentric training and supervised high load isometrics all improved symptoms similarly, but only the isometric group gained about 20% in tendon stiffness. Another heavy slow resistance study found stiffness gains unrelated to VISA scores. Mediation analysis of the LEAP trial in gluteal tendinopathy showed exercise worked partly through improved pain self-efficacy, reduced pain constancy and patient-specific function. A shoulder trial found high catastrophizing at baseline predicted a poorer response to exercise, which suggests addressing it early. Psychological factors appear to drive pain outcomes, while strength and stiffness change less over time. These are still important for function and may reduce recurrence, so rehabilitation should target both.