# 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 PMID: 37688638 Journal: European journal of applied physiology Published: 2024-02 Authors: Baltasar-Fernandez I, Alcazar J, Martín-Braojos S, Ara I, Alegre LM, García-García FJ, Alfaro-Acha A, Losa-Reyna J ## Question Does combining power-oriented resistance training with treadmill HIIT improve force-velocity characteristics, physical function, and frailty in pre-frail and frail older people, and do cluster-set and traditional resistance configurations differ? ## Summary In pre-frail and frail older adults, a supervised program that paired lower-body power-oriented resistance training with treadmill high-intensity intervals improved leg power, walking speed, SPPB physical function scores, and frailty status over about 6-8 weeks. Both traditional and cluster-set resistance formats were feasible with high attendance, but the study was not randomized and the control group was formed from people who declined or could not attend exercise. ## Population - Pre-frail and frail adults aged 75 years or older from a hospital frailty unit. - Sample size: 43 - Age: Mean 81.4 +/- 5.1 years. - Sex: Older men and women; sex distribution by group was not emphasized in the extracted evidence. - Fitness level: Clinical older adult population with functional limitations, not athletes. - Health status: Pre-frail or frail, with relatively preserved basic independence. ## Methodology - Quasi-experimental, single-blinded, non-randomized controlled intervention comparing traditional concurrent training, cluster-set concurrent training, and non-training control. - Approximately 6-8 weeks, with 2 sessions per week. - Frailty Unit at Hospital Virgen del Valle in Toledo, Spain. - Controlled study design. ## Protocol - Concurrent power-oriented resistance training plus treadmill HIIT. - Modality: Leg press and plantar-flexion resistance training followed by treadmill high-intensity intervals based on gait speed. - Work intervals: After an initial continuous conditioning phase, treadmill HIIT progressed from 6-10 bouts with work:rest around 1:5 to later bouts around 1:3. - Recovery: After an initial continuous conditioning phase, treadmill HIIT progressed from 6-10 bouts with work:rest around 1:5 to later bouts around 1:3. - Sets or repetitions: Sessions lasted about 45 minutes and combined lower-body resistance exercise with treadmill intervals. - Intensity: Resistance training used 30-60% of estimated maximal isometric force with the concentric phase performed as fast as possible. Treadmill intervals progressed toward bouts at 90% maximal gait speed with recovery at 50% usual gait speed. - Session duration: Sessions lasted about 45 minutes and combined lower-body resistance exercise with treadmill intervals. - Frequency: 2 sessions per week. - Program length: Approximately 6-8 weeks. - Progression: The first two weeks used 8-10 minutes of continuous treadmill exercise at 50% maximal gait speed. Later sessions used 10-30 second high-speed bouts with 50-100 second recoveries, progressing to 30 seconds at 90% maximal gait speed and 90 seconds at 50% usual gait speed. - A non-training control group continued usual care without the concurrent exercise program. - Modality: Participants were controls because they declined or could not attend the exercise intervention; no matched exercise attention condition was provided. ## Outcomes ### Both training formats improved maximal power Status: improved Both training formats improved maximal power: cluster training increased Pmax by about 36.7 +/- 34.2 W and traditional training by about 33.8 +/- 44.6 W. ### Short Physical Performance Battery Status: improved SPPB improved in all groups, but gains were larger in the training groups: about +43.5% for traditional training, +31.1% for cluster training, and +13.4% for control. ### Usual gait speed Status: improved Usual gait speed improved more in the training groups than control: about +26.8% for traditional training, +31.7% for cluster training, and +9.1% for control. ### Frailty Phenotype criteria Status: improved Frailty Phenotype criteria decreased in the training groups, about -1.1 criteria for cluster training and -1.6 criteria for traditional training, while control changed little. ### Force-velocity profile Status: improved Cluster training improved V0 significantly, while traditional training significantly improved F0; both formats produced broadly similar functional benefits. ## Practical Insights - For frail older adults, HIIT can be scaled to gait speed rather than running speed or maximal aerobic testing. - Very short treadmill bouts with long active recoveries may be a pragmatic way to introduce higher-intensity work in clinical older adults. - Combining HIIT with power-oriented resistance work may be important when the desired outcomes include mobility, frailty, and lower-limb power rather than aerobic fitness alone. - Cluster sets can maintain a high-velocity resistance-training intent by inserting short intra-set rests. ## Limitations - Allocation was not randomized, creating substantial selection bias risk. - The control group did not complete force-velocity testing, limiting between-group interpretation for key neuromuscular outcomes. - Small sample size, especially in the two exercise groups. - Participants were a special clinical older-adult population, limiting generalization to typical fitness users. - The intervention combined resistance training and HIIT, so the independent contribution of HIIT cannot be isolated. ## Safety And Adherence - The authors described the programs as safe in this clinical setting, including for participants with cardiac conditions in the cluster-training block, but detailed adverse-event counts were not extracted from the article text. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/37688638/) (pubmed) - [DOI](https://doi.org/10.1007/s00421-023-05298-x) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10858062/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.