ECSS Paris 2023: OP-MH08
INTRODUCTION: Resistance training (RT) improves physical function (PF) and strength in older adults. However, a dependency on health and exercise professionals may hinder older adults’ accessibility to RT. Replacing health and exercise professionals with peer volunteers may increase the accessibility of RT to older adults. The aim of this study was to determine the effectiveness of peer supervised RT for improving PF and strength in older adults. METHODS: Stage 1: Six RT trained older adults (68 ± 4 years, 50% female) completed a 4-week programme of workshops to prepare them for supervising RT sessions. The programme was designed and delivered by the lead researchers and topics included anatomy, principles of RT, RT for older adults, RT safety, exercise instruction, intensity monitoring, and an externally accredited sports first aid qualification. Stage 2: Ninety-eight community dwelling, healthy older adults (67 ± 4 years, 86% female) were randomly assigned to Peer Supervised RT (PEER), Professionally Supervised RT (PRO), or to a non-exercise Control (CON). Training groups completed 10 weeks of RT, training twice weekly. PF was assessed using the Timed Up-and-Go (TUG) and the 30 Second Chair Stand Test (30CST). Strength was measured using Handgrip dynamometry (HG). A two-way repeated measures ANOVA determined the effects of training and supervision type on physical outcomes. RESULTS: Drop-out rates were similar in PEER (22%) and PRO (25%). However, retention (defined as returning a completed training diary, attending > 50% of training sessions, and participating in all testing sessions) was higher in PRO (72%) than PEER (60%). Participants attended 80% of training sessions with no difference between groups. TUG improved in both PEER (8.24 ± 0.31s vs 7.00 ± 0.20s; p < 0.001, ηp2 = 0.31) and PRO (7.70 ± 0.28s vs 6.78 ± 0.178s; p < 0.001, ηp2 = 0.26), as did 30CST (PEER; 16.90 ± 0.85 stands vs 22.05 ± 1.00 stands; p < 0.001, ηp2 = 0.56 , PRO; 16.65 ± 0.77 stands vs 23.30 ± 0.91 stands; p < 0.001, ηp2 = 0.72) and HG (PEER; 27.10 ± 1.89kg vs 28.84 ± 1.83kg; p = 0.013, ηp2 = 0.10, PRO; 29.25 ± 1.713kg vs 33.28 ± 1.67kg; p < 0.001, ηp2 = 0.41). There were no changes in any of the outcome measures in CON. CONCLUSION: A 4-week programme of workshops was sufficient at providing voluntary peers with the skills required to effectively supervise a 10-week RT intervention for older adults. Peer supervised RT was as effective at improving PF and strength as professionally supervised RT.
Read CV Conor DowlingECSS Paris 2023: OP-MH08
INTRODUCTION: Aging is an inherent aspect of human life, characterized by a progressive decline in muscle mass and strength1. Older adults typically experience decreased muscle mass, alteration in muscle fiber size and composition, and impaired neuromuscular function compared to younger adults2. Physical exercise, particularly resistance training (RT), plays a primary role in counteracting age-related problems3. Understanding differences in adaptive response to RT between elderly and younger adults is crucial to optimize training outcomes for both populations. Therefore, we aimed to study changes in response to 8 weeks of RT focused on lower limbs between young adults (Y) and elderly (E). METHODS: Fourteen young adults (23.7±3.0 years) and seven older adults (71.9±5.7 years) underwent a progressive dynamic RT program (3 times/week) for 8 weeks. Training protocol involved 3 sets of leg press, lunges, and leg extension and 3 upper body exercises (2 sets). Neither group had prior experience with RT. Participants were assessed at the beginning (T0), after 4 (T1) and 8 (T2) weeks. Isometric muscle strength was evaluated during maximal voluntary force (MVC) and submaximal trapezoidal contractions (15, 35, 50, and 70%), with concurrent recording of high-density surface EMG (HDsEMG) from vastus lateralis muscle. Dynamic muscle strength was evaluated with 1RM leg press and leg extension. Body composition and muscle size (CSA) were assessed with DXA and ultrasonography (US), respectively. Moreover, muscle biopsies were obtained at T0 and T2. RESULTS: Preliminary results demonstrated a significant increase in strength parameters. Specifically, isometric MVC significantly increased (p<0.001) from T0 to T1 (Y=+8.52%, E: +15.51%) and from T0 to T2 (Y= +20.49%, E= +17.78%) in both groups and from T1 to T2 in Y only (+8.22%). Similar results were observed in 1RM test. US analysis revealed a time x age interaction (p<0.001) for quadriceps CSA: in particular, Y significantly increased muscle size at all time points, whilst E increased only from T0 to T2. Consequently, the ratio between MVC and CSA was unaltered in the Y group but increased from T0 to T2 in the E group. CONCLUSION: Our results suggest that an 8-week RT improved muscle strength parameters and CSA in both cohorts. However, it appears that the adaptive mechanism might be different: in the elderly strength gain seems more attributable to neural adaptation rather than morphological changes. This hypothesis could be further confirmed by the analysis of HDsEMG and muscle biopsies. 1= Lexell J, 1993 2=Mc Leod, 2016 3=Fiatarone, 1994
Read CV Gioi SpinelloECSS Paris 2023: OP-MH08
INTRODUCTION: Bioelectrical impedance analysis (BIA) parameters are often associated with cellular health and plausibly with muscle function. On the other hand, it is unknown whether prospective changes in muscle thickness due to resistance training (RT) are associated with changes in BIA-derived parameters. Therefore, we aimed to analyze the synergistic relationship between changes in muscle mass and BIA-derived parameters following 12 weeks of RT in older women. METHODS: One hundred and seventeen older women (69.4 yrs ± 5.7 yrs) were allocated either to a RT group (n = 56) to be submitted to a 12-week RT full-body program or to a control group (n = 61). Both groups were evaluated at the beginning of the study and after 12 weeks using a BIA device to assess reactance (Xc, ohms), resistance (R, ohms), and phase angle (PhA, º), while a B-mode ultrasound was used to determine muscle thickness of three sites (arm flexors, and lateral and mid-thigh). The sum of the three sites was used as a surrogate for muscle thickness measurements (SUMmt). Dual-energy X-ray absorptiometry was also used to estimate total fat mass (FM). Repeated measures correlation was used to examine the synergistic relationship between BIA parameters and muscle thickness over time, while linear mixed models with a random intercept were used to determine the relationship when adjusted for age and FM. RESULTS: After the intervention, Xc significantly increased in RT group (48.3 ± 7.8 to 52.8 ± 7.4) and reduced in control group (49.4± 8.22 to 46.7± 8.20), with a significant group*time interaction at the follow-up (P < 0.001). R increased only in RT group (555 ± 68 to 571 ± 63), while PhA increased in the RT group (4.97 ± 0.52 to 5.28± 0.50) and reduced in the control group (5.03 ± 0.48 to 4.78 ± 0.52), with a significant group*time interaction at the follow-up (P < 0.001). The SUMmt (cm) increased in RT group (18.2 ± 3.1 to 19.4 ± 3.0) and reduced in the control group (18.5 ± 2.8 to 17.9 ± 2.7), with a significant group*time interaction at the follow-up (P < 0.001). The SUMmt was associated with Xc (rrm = 0.50), R (rrm = 0.42), and PhA (rrm = 0.44) in the RT group, whereas no significant association was found between SUMmt and the BIA parameters in the control group (P ≥ 0.050). When adjusted by age and FM, a one-unit increase in the SUMmt in the RT group was associated with an increase of 0.83 ohms (CI 95%: 0.13/1.55 ohms) in Xc and 0.11º (CI 95%: 0.07/ 0.15º) in PhA, but not associated with R (P = 0.625). On the other hand, a one-unit increase in the SUMmt in the control group was associated with a reduction of -7.50 ohms (CI 95%: -12.6/-2.4 ohms) in R and 0.07º (CI 95%: 0.02/0.12º) in PhA, but it was not associated with Xc (P = 0.922). CONCLUSION: Changes in SUMmt induced by RT can explain a significant part of the BIA parameters in older women. Our results suggest that changes in muscle thickness due to RT might have a role in cellular health.
Read CV Natã StavinskiECSS Paris 2023: OP-MH08