Previous studies have demonstrated that eccentric training has a beneficial effect on Achilles tendinopathy, but few randomized controlled trials have compared it with other loading-based treatment regimens. This study sought to evaluate the effectiveness of eccentric training (ECC) and heavy slow resistance training (HSR) among patients with midportion Achilles tendinopathy. Both groups displayed significant (P < .0001) improvements in Victorian Institute of Sports Assessment-Achilles and visual analog scale from 0 to 12 weeks, and these improvements were maintained at the 52-week follow-up. Concomitant with the clinical improvement, there was a significant decrease in tendon thickness and neovascularization. None of these robust clinical and structural improvements varied between the ECC and HSR groups. However, patient satisfaction tended to be greater after 12 weeks with HSR (100%) than with ECC (80%; P = .052) but not after 52 weeks (HSR, 96%; ECC, 76%; P = .10), and the mean training session compliance rate was 78% in the ECC group and 92% in the HSR group, with a significant difference between groups (P < .005).
The results of this study demonstrate that both traditional ECC and HSR yield positive, equally good, lasting clinical results in patients with Achilles tendinopathy and that the latter tends to be related to greater patient satisfaction after 12 weeks but not after 52 weeks.