Power-oriented resistance training combined with high-intensity interval training in pre-frail and frail older people: comparison between traditional and cluster training set configurations on the force–velocity relationship, physical function and frailty

Objectives To analyse the force–velocity relationship changes in response to two different training programmes differing in the set configuration (cluster vs. traditional), and their impact on physical function and frailty in pre-frail and frail older adults. Methods 43 pre-frail and frail (Frailty Phenotype ≥ 1 criteria) older adults (81.4 ± 5.1 years) participated in this study. Participants were assigned to cluster (CT; n = 10; 10-s intra-set rest), traditional (TT; n = 13; no intra-set rest) or control (CON; n = 20) groups. Force–velocity relationship (F 0 , V 0 and P max ), physical function (Short Physical Performance Battery, SPPB) and frailty (Frailty Phenotype, FP) were assessed at baseline and after the training programme. Results Both CT and TT groups showed similar improvements in P max after training (CT = + 36.7 ± 34.2 W; TT = + 33.8 ± 44.6 W; both p < 0.01). V 0 was improved by both CT (+ 0.08 ± 0.06 m s −1 ; p < 0.01), and TT (+ 0.07 ± 0.15 m s −1 , p > 0.05). F 0 remained unchanged in CT (+ 68.6 ± 224.2 N, p > 0.05) but increased in TT (+ 125.4 ± 226.8 N, p < 0.05). Finally, SPPB improved in both training conditions (CT = + 2.3 ± 1.3 points; TT = + 3.0 ± 1.2 points; both p < 0.05) and in the CON group (+ 0.9 ± 1.4 points, p < 0.05). CT and TT reduced their FP (CT = − 1.1 criteria; TT = − 1.6 criteria; both p < 0.01), while no changes were observed in the CON group (− 0.2 criteria, p = 0.38). Conclusions Both training methods were equally effective for improving P max , physical function and reducing frailty in pre-frail and frail older people. TT may be effective for improving both force and velocity parameters, while CT may be effective for improving velocity parameters alone, although further research is required to confirm these findings.