Acute Effect of Dynamic and Gluteal Resistance Exercise Warm-up Protocols on Jump Landing Mechanics in College-Aged Females.

ABSTRACT: Rauseo, ML, Feairheller, DL, LaRoche, DP, and Cook, SB. Acute effect of dynamic and gluteal resistance exercise warm-up protocols on lower-extremity jump landing mechanics in college-aged females. J Strength Cond Res 38(2): 259-265, 2024-Inadequate neuromuscular control of the femur by the gluteal musculature is associated with noncontact and overuse injuries to the knee. Acute bouts of resistance exercises targeting the gluteal musculature can be prescribed as part of a warm-up protocol with the goal of improving subsequent neuromuscular control and performance. The purpose of this study was to determine the effect that a warm-up protocol including moderate-intensity gluteal resistance exercises (GRE) has on single leg jump landing biomechanics. Seventeen healthy, college-aged, recreationally active females (mean ± SD ; age = 21.4 ± 1.9 years; height = 166.9 ± 5.7 cm; body mass = 62.5 ± 7.4 kg) performed 3 single leg hop trials per leg after completing no warm-up (CON), a dynamic warm-up (DWU), and a dynamic warm-up with gluteal resistance exercises (DWU + GRE) across 3 laboratory visits. Lower extremity kinetic and kinematic variables were assessed during single leg hops from the point of initial foot contact to deepest knee flexion. Biomechanical differences between dominant and nondominant limb landings were also assessed. Dominant limb hip internal rotation angle after DWU + GRE (2.03 ± 9.92°) was significantly greater ( p ≤ 0.05) compared with CON (-3.36 ± 7.74°). Peak knee adduction moment (56.8%), peak knee flexion angle (5.7%), and peak knee external rotation angle (17.0%) were significantly greater ( p ≤ 0.017) in the dominant limb, compared with the nondominant limb, across warm-up protocols. The combined DWU + GRE warm-up protocol did not have a substantial impact on landing biomechanics. Clinicians prescribing GRE before activity should not expect significant changes in movement patterns after a single bout.

Acute physiological responses to steady-state arm cycling ergometry with and without blood flow restriction.

PURPOSE: To compare heart rate (HR), oxygen consumption (VO2), blood lactate (BL), and ratings of perceived exertion (RPE) during arm cycling with and without a blood flow restriction (BFR). METHODS: Twelve healthy males (age: 23.9 ± 3.75 years) completed four, randomized, 15-min arm cycling conditions: high-workload (HW: 60% maximal power output), low-workload (LW: 30% maximal power output), low-workload with BFR (LW-BFR), and BFR with no exercise (BFR-only). In the BFR conditions, cuff pressure to the proximal biceps brachii was set to 70% of occlusion pressure. HR, VO2, and RPE were recorded throughout the exercise, and BL was measured before, immediately after, and five minutes post-exercise. Within-subject repeated-measures ANOVA was used to evaluate condition-by-time interactions. RESULTS: HW elicited the greatest responses in HR (91% of peak; 163.3 ± 15.8 bpm), VO2 (71% of peak; 24.0 ± 3.7 ml kg-1 min-1), BL (7.7 ± 2.5 mmol L-1), and RPE (14 ± 1.7) and was significantly different from the other conditions (p < 0.01). The LW and LW-BFR conditions did not differ from each other in HR, VO2, BL, and RPE mean of conditions: ~ 68%, 41%, 3.5 ± 1.6 mmol L-1, 10.4 ± 1.6, respectively; p > 0.05). During the BFR-only condition, HR increased from baseline by ~ 15% (on average) (p < 0.01) without any changes in VO2, BL, and RPE (p > 0.05). CONCLUSIONS: HW arm cycling elicited the largest and most persistent physiological responses compared to LW arm cycling with and without a BFR. As such, practitioners who prescribe arm cycling for their clients should be advised to augment the demands of exercise via increases in exercise intensity (i.e., power output), rather than by adding BFR.

Feasibility and acceptability of a technology-based, rural weight management intervention in older adults with obesity.

BACKGROUND: Older adults with obesity residing in rural areas have reduced access to weight management programs. We determined the feasibility, acceptability and preliminary outcomes of an integrated technology-based health promotion intervention in rural-living, older adults using remote monitoring and synchronous video-based technology. METHODS: A 6-month, non-randomized, non-blinded, single-arm study was conducted from October 2018 to May 2020 at a community-based aging center of adults aged ≥65 years with a body mass index (BMI) ≥30 kg/m2. Weekly dietitian visits focusing on behavior therapy and caloric restriction and twice-weekly physical therapist-led group strength, flexibility and balance training classes were delivered using video-conferencing to participants in their homes. Participants used a Fitbit Alta HR for remote monitoring with data feedback provided by the interventionists. An aerobic activity prescription was provided and monitored. RESULTS: Mean age was 72.9±3.9 years (82% female). Baseline anthropometric measures of weight, BMI, and waist circumference were 97.8±16.3 kg, 36.5±5.2 kg/m2, and 115.5±13.0 cm, respectively. A total of 142 participants were screened (n=27 ineligible), and 53 consented. There were nine dropouts (17%). Overall satisfaction with the trial (4.7+ 0.6, scale: 1 (low) to 5 (high)) and with Fitbit (4.2+ 0.9) were high. Fitbit was worn an average of 81.7±19.3% of intervention days. In completers, mean weight loss was 4.6±3.5 kg or 4.7±3.5% (p< 0.001). Physical function measures of 30-s sit-to-stand repetitions increased from 13.5±5.7 to 16.7±5.9 (p< 0.001), 6-min walk improved by 42.0±77.3 m (p=0.005) but no differences were observed in gait speed or grip strength. Subjective measures of late-life function improved (3.4±4.7 points, p< 0.001). CONCLUSIONS: A technology-based obesity intervention is feasible and acceptable to older adults with obesity and may lead to weight loss and improved physical function. CLINICAL TRIAL REGISTRATION: Registered on Clinicaltrials.gov # NCT03104205 . Registered on April 7, 2017. First participant enrolled on October 1st, 2018.

A feasibility study of an unsupervised, pre-operative exercise program for adults with lung cancer.

OBJECTIVE: The purpose of this study was to explore the feasibility, acceptability and perceived utility of the provision of a wearable fitness device and an exercise prescription from a surgeon, prior to surgery for lung cancer. METHODS: A single-arm, pre-post feasibility study was conducted with 30 participants scheduled for surgery to treat stage I, II or III lung cancer. Participants were given a Garmin Vivoactive HR device and a prescription for 150 min of moderately to vigorous exercise per week. Participants completed assessments on four occasions and completed a semi-structured interview on two occasions. Descriptive statistics were used to assess the feasibility and acceptability of study procedures, including synchronising the Garmin device and engaging in study assessments. RESULTS: Seventy-nine per cent of enrolled participants completed the pre-operative study activities. Seventy-one per cent of enrolled participants successfully synchronised their device during the pre-operative period. Data were transmitted from the device to the study team for an average of 70% of the pre-operative days. CONCLUSION: This pilot study demonstrated the feasibility and acceptability of a pre-operative exercise program for patients scheduled to undergo surgery for lung cancer. TRIAL REGISTRATION: The study protocol was registered with ClinicalTrials.gov prior to the initiation of participant recruitment (NCT03162718).

Postactivation Potentiation in Blood Flow-Restricted Complex Training.

Cleary, CJ and Cook, SB. Postactivation potentiation in blood flow-restricted complex training. J Strength Cond Res 34(4): 905-910, 2020-Complex training uses a high-load (HL) resistance exercise to elicit postactivation potentiation (PAP) that is typically observed through enhanced plyometric performance. Blood flow-restricted (BFR) resistance exercise uses low loads to induce similar muscular adaptations to HL resistance exercise; however, the efficacy and feasibility of BFR complex training are unknown. Fifteen college-aged men (mean ± SD; age: 20.3 ± 0.9 years; relative back-squat one-repetition maximum [1RM]: 1.78 ± 0.3 kg·kg) with at least 2 years of resistance training experience completed 3 sessions: a familiarization session with 1RM testing, and 2 complex training sessions of 3 presquat vertical jumps (VJs), condition-specific back squats (HL: 5 repetitions at 85% 1RM, BFR: 30 repetitions at 30% 1RM), and a single postsquat VJ. Postactivation potentiation was calculated as (postsquat VJ height ÷ max presquat VJ height) [BULLET OPERATOR] 100. Electromyography (EMG) of the vastus lateralis and hamstrings was collected, quantified to root mean square values, and normalized to peak 1RM activity. Postsquat VJ height was significantly reduced in both conditions, and PAP did not occur because it was less than 100% (HL: 96.1 ± 5.1%, BFR: 90.8 ± 7.8%, p = 0.010). Vastus lateralis and hamstrings EMG amplitude was highest (p < 0.001) in the HL condition. High-load and BFR complex training decreased subsequent VJ height in these individuals, and this might have been due to an ineffective complex training protocol and individual factors such as training status and relative strength.

Neuromuscular Adaptations to Low-Load Blood Flow Restricted Resistance Training.

Low-load blood flow restricted (BFR) resistance exercise has been suggested to be as effective as moderate and high-load resistance training for increasing muscle size and strength. The purpose of the study was to evaluate the effects of 6 weeks of HL or low-load BFR resistance training on neuromuscular function, strength, and hypertrophy of the knee extensors. Eighteen participants aged 18-22 years old were randomized to one of three training groups: moderate load (ML: 70% of 1 repetition maximum [1-RM]); BFR (20% 1-RM with a vascular restriction set to ~180 mmHg); and a control group (CON) that did not exercise. Participants performed leg extension (LE) and leg press exercises 3 times per week for 6 weeks. Measurements of isometric torque, LE 1-RM, central activation, electrically evoked torque, and muscle volume of the knee extensors were obtained before and after training. Isometric peak torque did not change following the training (p = 0.13). LE 1-RM improved in the ML (34 ± 20%; d = 0.78) and BFR (14 ± 5%; d = 0.67) groups compared to the CON group (0.6 ± 8%; d = 0.09; time x group interaction p = 0.02). Muscle volume increased in the ML (5.6%; d = 0.19) and BFR groups (2.5%; d = 0.09) with no change in the CON group (time x group interaction p = 0.001). There were no changes in central activation and evoked torque in any groups following the training (p > 0.05). Strength and hypertrophy were evident following ML and BFR resistance training programs indicating that both modalities are effective, although ML training appears to be a more potent and efficient. Neuromuscular changes were not evident and warrant more research.

Asymmetry of lower extremity force and muscle activation during knee extension and functional tasks.

INTRODUCTION: Strength and power asymmetries of >10% may negatively impact physical function. METHODS: Twenty-four healthy participants, 30-60 years of age, were assessed for muscle power asymmetry during isokinetic knee extension and ground reaction force asymmetry during chair-rise and vertical jump tasks. Neuromuscular activation asymmetry and coactivation of vastus lateralis (VL) and biceps femoris (BF) were assessed in each condition. Symmetric (SG) and asymmetric (AG) groups were identified using a 10% knee extension power asymmetry criterion. RESULTS: The AG had greater chair-rise rate of force development asymmetry (P = 0.003, d = 1.29), but a similar chair-rise and vertical jump peak force asymmetry as the SG. Large group effects were found for VL activation asymmetry during knee extension (P = 0.047, d = 0.87), BF activation asymmetry during vertical jump (P = 0.015, d = 1.12), and strong leg coactivation during vertical jump (P = 0.028, d = 0.96). CONCLUSIONS: Compensation for muscle power asymmetry may occur during functional tasks, potentially through differential activation of strong and weak leg muscles. Muscle Nerve 56: 495-504, 2017.

Neuromuscular function following muscular unloading and blood flow restricted exercise.

PURPOSE: The aim of the study is to evaluate central and peripheral neuromuscular function in the knee extensors (KE) and plantar flexors (PF) after 30 days of unilateral lower limb suspension (ULLS) and to examine the effects of low-load blood flow restricted (BFR) resistance training on the KE during ULLS. METHODS: Strength, cross-sectional area (CSA), central activation, evoked force, and rates of force development and relaxation were assessed in the KE and PF before and after ULLS in sixteen subjects (9 M, 7F; 18-49 years). Eight of those subjects participated in BFR on the KE three times per week during ULLS (ULLS + Exercise). RESULTS: The ULLS group had decrements in strength and CSA of the KE (16 and 7 %, respectively) and PF (27 and 8 %, respectively) and the ULLS + Exercise maintained strength and CSA of the KE (P > 0.05), but significantly lost strength and CSA in the PF (21 and 5 %; P > 0.05). KE central activation declined 6 % in the ULLS group and was maintained in the ULLS + Exercise group, but a time × group interaction was not evident (P = 0.31). PF central activation was reduced in both groups (ULLS: -7.6 ± 9.9 and -7.9 ±11.6 %; time main effect P = 0.01). A time × group interaction for KE-evoked twitch force (P = 0.04) demonstrated a 9 % decline in the ULLS + Exercise group following the intervention. Evoked PF doublet torque decreased 12 % in both groups (P = 0.002). CONCLUSION: Central and peripheral neuromuscular function is compromised during unloading. While BFR resistance training on the KE during unloading can maintain muscle mass and strength, it may only partially attenuate neuromuscular dysfunction.

Changes in Weight or Body Composition by Frailty Status: A Pilot Study.

Weight loss may benefit older adults with obesity. However, it is unknown whether individuals with different frailty phenotypes have different outcomes following weight loss. Community-dwelling adults aged ≥65 (n = 53) with a body mass index ≥30 kg/m2 were recruited for a six-month, single-arm, technology-based weight loss study. A 45-item frailty index identified frailty status using subjective and objective measures from a baseline geriatric assessment. At baseline, n = 22 participants were classified as pre-frail (41.5%) and n = 31 were frail (58.5%), with no differences in demographic characteristics. While weight decreased significantly in both groups (pre-frail: 90.8 ± 2.7 kg to 85.5 ± 2.4 kg (p < 0.001); frail: 102.7 ± 3.4 kg to 98.5 ± 3.3 kg (p < 0.001), no differences were observed between groups for changes in weight (p = 0.30), appendicular lean mass/height2 (p = 0.47), or fat-free mass (p = 0.06). Older adults with obesity can safely lose weight irrespective of frailty status using a technology-based approach. Further investigation is needed to determine whether the impact of specific lifestyle interventions differ by frailty status.

Relationship of Handgrip Strength and Asymmetry with Walking Ability in Older Adults with Excess Adiposity.

When low muscle mass and impaired strength and physical function coexist with excess adiposity, it is termed sarcopenic obesity (SO). Handgrip strength (HGS) is a predictor of disability and mortality. Asymmetry in HGS, particularly ≥ 10% strength differences between hands, may indicate neuromuscular dysfunction observable prior to declines in maximal strength are detectedand therefore could be incorporated to identify those at risk of physical limitations and SO. This study compares HGS values and asymmetry in older adults with excess adiposity and evaluates their relationships with physical function. Baseline data from two previous pilot weight loss studies in 85 older adults with body mass index values ≥ 30 kg m-2 are included with measures of body composition, walking speed, and chair stand ability. Sixty-three participants met the criteria for SO. HGS correlated to gait speed (r = 0.22), distance walked (r = 0.40), chair stand time for 5 repetitions (r = 0.42) and during 30 s (r = 0.31). HGS asymmetry is only correlated to gait speed (r = 0.31) and there are no differences in physical function between those with and without asymmetry. Maximal HGS tests should continue to be used to screen for functional decline and disability.

Using a Walking Test to Assess Firefighter Fitness.

Tactical populations face increased risk on the job, and it is known that firefighters have high levels of cardiac-related death. Aerobic fitness is a modifiable cardiac risk factor, but many fire stations lack the proper equipment to easily assess aerobic fitness levels of their firefighters. Additionally, many fire stations lack wellness programs to hold firefighters accountable for maintaining their fitness levels. Purpose: We assessed the validity of the submaximal 6-minute walk test (6MWT) as a measure of aerobic capacity compared to a maximal treadmill test and the submaximal Gerkin protocol. Methods: Twenty-four firefighters (19 male, 5 female, 34.8 ± 9.7 years; 38.1 ± 3.6 kg·m-2) completed the 6MWT, the submaximal Gerkin protocol, and a maximal treadmill test. Data were analyzed with Bland-Altman plots and correlation analysis. Results: We found equivalence between the 6MWT and directly measured VO2max and between the 6MWT and Gerkin protocol using Bland-Altman plots. In our cohort, the 6MWT underestimated VO2max (31.57 ml·kg-1·min-1) compared to directly measured VO2max (38.1 ml·kg-1·min-1) by 17% and to the Gerkin (40.48 ml·kg-1·min-1) by 22%. Conclusion: Considering its equivalence, using the 6MWT could be a more accessible way to quantify aerobic capacity in firefighters. Despite underestimation, having an easy to administer protocol may encourage more fire stations to assess pre- and post- fitness levels regularly.

Effect of cryotherapy on muscle recovery and inflammation following a bout of damaging exercise.

The purpose of this study was to determine the effect of cryotherapy on the inflammatory response to muscle-damaging exercise using a randomized trial. Twenty recreationally active males completed a 40-min run at a -10 % grade to induce muscle damage. Ten of the subjects were immersed in a 5 °C ice bath for 20 min and the other ten served as controls. Knee extensor peak torque, soreness rating, and thigh circumference were obtained pre- and post-run, and 1, 6, 24, 48, and 72 h post-run. Blood samples were obtained pre- and post-run, and 1, 6 and 24 h post-run for assay of plasma chemokine ligand 2 (CCL2). Peak torque decreased from 270 ± 57 Nm at baseline to 253 ± 65 Nm post-run and increased to 295 ± 68 Nm by 72 h post-run with no differences between groups (p = 0.491). Soreness rating increased from 3.6 ± 6.0 mm out of 100 mm at baseline to 47.4 ± 28.2 mm post-run and remained elevated at all time points with no differences between groups (p = 0.696). CCL2 concentrations increased from 116 ± 31 pg mL(-1) at baseline to 293 ± 109 pg mL(-1) at 6 h post-run (control) and from 100 ± 27 pg mL(-1) at baseline to 208 ± 71 pg mL(-1) at 6 h post-run (cryotherapy). The difference between groups was not significant (p = 0.116), but there was a trend for lower CCL2 in the cryotherapy group at 6 h (p = 0.102), though this measure was highly variable. In conclusion, 20 min of cryotherapy was ineffective in attenuating the strength decrement and soreness seen after muscle-damaging exercise, but may have mitigated the rise in plasma CCL2 concentration. These results do not support the use of cryotherapy during recovery.

Comparison of the H:Q Ratio Between the Dominant and Nondominant Legs of Soccer Players: A Meta-analysis.

CONTEXT: Soccer players often have a dominant (D) leg, which could influence the relative strength between the quadriceps and hamstrings. The hamstring-to-quadriceps (H:Q) ratio can be assessed on a dynamometer at various velocities to provide information on injury risk. OBJECTIVE: To assess the concentric hamstrings and concentric quadriceps strength ratio (conventional H:Q ratio) assessed in D and nondominant (ND) legs at various speeds in male soccer players. DATA SOURCES: A systematic literature search was completed from inception to 2020 in PubMed, Academic Search Ultimate, CINAHL, and SPORTDiscus. STUDY SELECTION: Keywords associated with the H:Q ratio were connected with terms for soccer players. Titles and abstracts were screened by 2 reviewers based on inclusion and exclusion criteria related to sex, playing level, language, and measurement. A total of 81 studies were reviewed and 17 studies (21%) were used. STUDY DESIGN: A meta-analysis with random effects modeling generated standardized mean differences with 95% CIs between legs and speeds. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: A total of 38 cohorts were identified, with 14, 13, and 11 cohorts assessed at low, intermediate, and high velocities, respectively. The Quality Assessment Tool for Observational Cohort and Cross-sectional Studies from the National Institutes of Health was used. RESULTS: The mean H:Q ratio at low velocities was 59.8 ± 9.5% in D leg and 58.6 ± 9.9% in ND leg, 64.2 ± 10.7% (D) and 63.6 ± 11.3% (ND) at the intermediate velocity, and 71.9 ± 12.7% (D) and 72.8 ± 12.7% (ND) at the high velocity. Low, intermediate, and high velocities had small effects of 0.13, 0.10, and -0.06, respectively. CONCLUSION: Conventional H:Q ratios vary across velocities but did not differ between D and ND limbs in male soccer players. This study may provide the foundation to establish norms and clinically meaningful differences.

Protein Supplementation May Dampen Positive Effects of Exercise on Glucose Homeostasis: A Pilot Weight Loss Intervention.

BACKGROUND: The role of protein in glucose homeostasis has demonstrated conflicting results. However, little research exists on its impact following weight loss. This study examined the impact of protein supplementation on glucose homeostasis in older adults >65 years with obesity seeking to lose weight. METHODS: A 12-week, nonrandomized, parallel group intervention of protein (PG) and nonprotein (NPG) arms for 28 older rural adults (body mass index (BMI) ≥ 30 kg/m2) was conducted at a community aging center. Both groups received twice weekly physical therapist-led group strength training classes. The PG consumed a whey protein supplement three times per week, post-strength training. Primary outcomes included pre/post-fasting glucose, insulin, inflammatory markers, and homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS: Mean age and baseline BMI were 72.9 ± 4.4 years and 37.6 ± 6.9 kg/m2 in the PG and 73.0 ± 6.3 and 36.6 ± 5.5 kg/m2 in the NPG, respectively. Mean weight loss was -3.45 ± 2.86 kg in the PG and -5.79 ± 3.08 kg in the NPG (p < 0.001). There was a smaller decrease in pre- vs. post-fasting glucose levels (PG: -4 mg ± 13.9 vs. NPG: -12.2 ± 25.8 mg/dL; p = 0.10), insulin (-7.92 ± 28.08 vs. -46.7 ± 60.8 pmol/L; p = 0.01), and HOMA-IR (-0.18 ± 0.64 vs. -1.08 ± 1.50; p = 0.02) in the PG compared to the NPG. CONCLUSIONS: Protein supplementation during weight loss demonstrated a smaller decrease in insulin resistance compared to the NPG, suggesting protein may potentially mitigate beneficial effects of exercise on glucose homeostasis.

Nutrition and resistance exercise during reconditioning from unloading.

INTRODUCTION: The recovery of muscle size and function following musculoskeletal unloading has received little attention in the scientific literature. Nutritional factors such as total energy, protein intake, and the pre- and/or post-exercise consumption of amino acid-carbohydrate (AACHO) have been shown to be important for enhancing training adaptations in recreational exercisers. PURPOSE: A preliminary study was conducted to explore the interaction between nutrition and resistance exercise during reconditioning from unloading. METHODS: Muscle CSA, strength, and endurance were measured during a control period following 30 d of unilateral lower limb suspension (Post-ULLS) and after 18 d of reconditioning (ReCon). Six participants consumed either AACHO (979 kJ, 36 g carbohydrate, 22.5 g protein) or placebo (PLAC) prior to resistance exercise (3 d x wk(-1)) during reconditioning. Total daily energy and macronutrient intake were evaluated from dietary journals. RESULTS: From Post-ULLS to ReCon, muscle endurance increased 1.1 +/- 0.6 min in AACHO and decreased 1.3 +/- 0.7 min in PLAC. Muscle CSA (6 +/- 2 vs. 5 +/- 3 cm2) and strength (105 +/- 53 vs. 81 +/- 37 N) increased similarly in AACHO and PLAC, respectively. When groups were pooled there was a significant correlation between daily protein intake and the recovery of muscle CSA (r = 0.81). DISCUSSION: Although our findings are preliminary, timing AACHO intake during reconditioning was beneficial for muscular endurance, while overall protein intake was associated with increased muscle size. A systematic evaluation into the synergistic relationship between nutrition and exercise during muscular recovery from prolonged unloading is warranted.

Evaluation of muscle thickness of the vastus lateralis by ultrasound imaging following blood flow restricted resistance exercise.

BACKGROUND: Blood flow restricted (BFR) exercise results in transient muscle growth that may be due to metabolite accumulation, hyperaemia and muscle damage, possibly serving as a stimulus for hypertrophy. Understanding the duration of this growth is important for exercise recovery and measurement of hypertrophy. PURPOSE: To measure changes in muscle size via ultrasound throughout a 48-h period after a session of BFR knee extension (KE) exercise. METHODS: Muscle thickness of the vastus lateralis (VL) was measured via ultrasound in 12 participants (six males and six females, age: 20.3 ± 1.1 years) before and immediately, 10 min, 30 min, 1, 3, 8, 24, and 48 h after unilateral exercise. One leg served as a non-exercise control while the other leg performed four sets of unilateral BFR KE at 30% of one-repetition maximum with a pressurized cuff applied to the proximal thigh and inflated to 50% arterial occlusion pressure. RESULTS: Vastus lateralis thickness was 34.9 ± 7.2% higher immediately after exercise, 28.6 ± 7.9% at 10 min, 25.2 ± 6.1% at 30 min, 14.9 ± 4.8% at 1 h and 11.8 ± 5.6% at 3 h (p < 0.05). There were no changes compared to pre-exercise measurements past 3 h, and the control limb did not change (p > 0.05). The muscle thickness of the exercise leg was significantly greater than that of the control leg from immediately after exercise up to 1 h post-exercise (p < 0.05). CONCLUSION: Muscle thickness of the VL increases for 3 h post-BFR exercise and returns to normal within 8 h. This timeframe should be considered when prescribing exercise and planning muscle hypertrophy assessments.

Resistance Training With Partial Blood Flow Restriction in a 99-Year-Old Individual: A Case Report.

In aging populations for which the use of high loads is contraindicated, low load resistance training associated with blood flow restriction (RT-BFR) is an alternative strategy to induce muscle mass gains. This study investigates the effects of RT-BFR on muscle mass, muscle function, and quality of life of a 99-year-old patient with knee osteoarthritis and advanced muscle mass deterioration. Training protocol consisted of 24 sessions of a unilateral free-weight knee extension exercise associated with partial blood flow restriction through a manometer cuff set at 50% of complete vascular occlusion pressure. We evaluated: cross-sectional area (CSA) and thickness (MT) of the vastus lateralis muscle by ultrasound; function through the Timed Up and Go (TUG) test; and quality of life (QoL) by the WHOQOL-bref, WHOQOL-OLD and WOMAC questionnaires. All tests were performed prior to the training period (Pre) and after the 12th (Mid) and 24th (Post) sessions. Changes were considered significant if higher than 2 times the measurement's coefficient of variation (CV). After 24 sessions, there was an increase of 12% in CSA and 8% in MT. Questionnaires scores and TUG values worsened from Pre to Mid and returned in Post. We consider RT-BFR a viable and effective strategy to promote muscle mass gains in nonagenarians and delay the decline in functionality and QoL associated with aging.

Impact of whey protein supplementation in a weight-loss intervention in rural dwelling adults: A feasibility study.

BACKGROUND & AIMS: Weight loss in older adults enhances physical function, but may lead to sarcopenia and osteoporosis. Whey protein is a low cost rich source of essential amino acids, may improve physical function. We evaluated the feasibility and acceptability of consuming whey protein in the context of a weight-loss intervention in older adults with obesity. METHODS: A 12-week pilot feasibility, non-randomized weight loss study of 28 older adults was conducted, consisting of individualized, weekly dietitian visits with twice weekly physical therapist-led group strengthening classes. Half consumed whey protein, three times weekly, following exercise. Preliminary efficacy measures of body composition, sit-to-stand, 6-min walk and grip strength and subjective measures of self-reported health and function were also evaluated. RESULTS: Of the 37 enrolled, 28 completed the study (50 % in the protein group). Attendance rates for protein vs. non-protein groups were 89.9 ± 11.1 % vs. 95.6 ± 3.4 % (p = 0.08). Protein consumption was high in those attending classes (90.3 %) as was compliance at home (82.6 %). Whey was pleasant (67.3 ± 22.1, range 30-100, above average), had little aftertaste, and was neither salty or sticky. All were compliant (0.64 ± 0.84, range 0-5, low = higher compliance). Both groups lost significant weight (protein vs. no protein, -3.45 ± 2.86 vs. -5.79 ± 3.08, p = 0.47); Sit-to-stand, 6-min walk, and gait speed were no different, grip strength was improved in the protein compared to the non-protein group (-2.63 kg vs. 4.29 kg; p < 0.001). CONCLUSIONS: Our results suggest that whey protein is a low-cost and readily available nutritional supplement that can be integrated into a weight loss intervention.

A Weight Loss Intervention Augmented by a Wearable Device in Rural Older Adults With Obesity: A Feasibility Study.

BACKGROUND: Older persons with obesity aged 65+ residing in rural areas have reduced access to weight management programs due to geographic isolation. The ability to integrate technology into health promotion interventions shows a potential to reach this underserved population. METHODS: A 12-week pilot in 28 older rural adults with obesity (body mass index [BMI] ≥ 30 kg/m2) was conducted at a community aging center. The intervention consisted of individualized, weekly dietitian visits focusing on behavior therapy and caloric restriction with twice weekly physical therapist-led group strengthening training classes in a community-based aging center. All participants were provided a Fitbit Flex 2. An aerobic activity prescription outside the strength training classes was provided. RESULTS: Mean age was 72.9 ± 5.3 years (82% female). Baseline BMI was 37.1 kg/m2, and waist circumference was 120.0 ± 33.0 cm. Mean weight loss (pre/post) was 4.6 ± 3.2 kg (4.9 ± 3.4%; p < .001). Of the 40 eligible participants, 33 (75%) enrolled, and the completion rate was high (84.8%). Objective measures of physical function improved at follow-up: 6-minute walk test improved: 35.7 ± 41.2 m (p < .001); gait speed improved: 0.10 ± 0.24 m/s (p = .04); and five-times sit-to-stand improved by 2.1 seconds (p < .001). Subjective measures of late-life function improved (5.2 ± 7.1 points, p = .003), as did Patient-Reported Outcome Measurement Information Systems mental and physical health scores (5.0 ± 5.7 and 4.4 ± 5.0, both p < .001). Participants wore their Fitbit 93.9% of all intervention days, and were overall satisfied with the trial (4.5/5.0, 1-5 low-high) and with Fitbit (4.0/5.0). CONCLUSIONS: A multicomponent obesity intervention incorporating a wearable device is feasible and acceptable to older adults with obesity, and potentially holds promise in enhancing health.