Effects of detraining on muscle strength and mass after high or moderate intensity of resistance training in older adults

Classical Ballet for Women Aged Over 50 Years: Investigating Balance, Strength, and Range of Motion

Background: Regular exercise can mitigate the loss of strength, balance, and flexibility that contribute to age-related decline in physical function and mobility. However, traditional exercise interventions often report poor adherence rates. There is growing interest in classical ballet as an enjoyable exercise modality for adults in middle to late age. Classical ballet requires muscular strength, coordination, and flexibility. The current study investigated a classical ballet intervention on the balance, physical function, and range of motion of women aged over 50 years. Methods: Twenty-two healthy female participants (aged 56.2 (4.5) years (mean (SD)) completed a 10-week ballet intervention. Results: This single-arm study showed significant improvements (p<.05) in lower limb strength (measured by 5 times sit-to-stand and forward leap) and high adherence rates (95% adherence for participants who completed the intervention). No adverse events were reported. Improvements in balance were reported in the left leg only (as measured by center of pressure ellipse area in the parallel retiré condition). Conclusions: These results allude to the positive effects of ballet training on strength and balance in adults aged 50 years and over. High adherence rates suggest that ballet training was enjoyed and may thus be a long-term exercise modality for this population. Although this study was a single-arm design, it suggests promising results for future research wishing to evaluate the effectiveness of classical ballet training using randomized controlled trial designs.

The Effect of a Resistance Training, Detraining and Retraining Cycle on Postural Stability and Estimated Fall Risk in Institutionalized Older Persons: A 40-Week Intervention

Physical inactivity and low levels of muscle strength can lead to the early development of sarcopenia and dynapenia, which may increase the number and risk of falls in the elderly population. Meanwhile, exercise programs can stop or even revert the loss of muscle mass, strength, power, and functional capacity and consequently decrease the risk of falls in older adults. However, there is a lack of studies investigating the effect of strengthening programs in octogenarians. The present study investigates the effects of 40 weeks of a training-detraining-retraining cycle of muscle strength exercise program on postural stability and estimated fall risk in octogenarians. Twenty-seven institutionalized participants were allocated into two groups: the muscular strength exercise group (MSEG, n = 14) and control group (CG, n = 13). After the first training period, the MSEG improved postural stability and decreased the estimated fall risk by 7.9% compared to baseline. In comparison, CG worsened their stability and increased their risk of falling by more than 17%. No significant changes were found between groups in the detraining and the retraining period. This study demonstrated that strength exercise effectively improved postural control and reduced fall risk scores. In addition, the interventions were able to reduce the forward speed of postural control deterioration in octogenarians, with great increments in the first months of exercise.

Training Session and Detraining Duration Affect Lower Limb Muscle Strength Maintenance in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis

Muscle strength after detraining is still higher than the level before training, which is an important issue for middle-aged and older adults. The purpose of the present study was to examine the effects of detraining duration (DD), resistance training duration (RTD), and intensity on the maintenance of resistance training (RT) benefits after detraining in middle-aged and older adults. A systematic search yielded 15 randomized control trails (n = 383) eligible for inclusion. The results showed that RTD ≥ 24 weeks and DD ≥ RTD, the RT benefits were still significantly maintained even with medium and low intensity (standardized mean difference = 1.16, 95% confidence interval, CI [0.38, 1.94], p = .004). When RTD < 24 weeks and DD ≤ RTD, only the high-intensity groups maintained the RT benefits (DD, 4-6 weeks: standardized mean difference = 0.71, 95% CI [0.34, 1.08], p = .0002; DD 8-16 weeks: standardized mean difference = 1.35, 95% CI [0.66, 2.04], p = .0001). However, when DD > RTD, the RT benefits were not maintained even with high intensity. In summary, when RTD was less than 24 weeks, RTD > DD was an important factor in maintaining muscle strength.

Detraining Effects on Musculoskeletal Parameters in Early Postmenopausal Osteopenic Women: 3-Month Follow-Up of the Randomized Controlled ACTLIFE Study

Periods of absence from supervised group exercise while maintaining physical activity might be a frequent pattern in adults' exercise habits. The aim of the present study was to determine detraining effects on musculoskeletal outcomes after a 3-month detraining period in early post-menopausal, osteopenic women. Due to the COVID-19 pandemic, we terminated the 18-month randomized controlled ACTLIFE exercise intervention immediately after the 13-month follow-up assessment. This put an abrupt stop to the high-intensity aerobic and resistance group exercise sessions undertaken three times per week by the exercise group (EG: n = 27) and the gentle exercise program performed once per week for the attention control group (CG: n = 27); but both groups were permitted to conduct individual outdoor activity for the 3-month lock-down period. Study endpoints were lean body mass (LBM), bone mineral density (BMD) at the lumbar spine (LS), maximum hip-/leg extension strength and power. Detraining-induced reductions of LBM, hip/leg strength and power (but not BMD-LS) were significantly greater (p < 0.001 to p = 0.044) compared with the CG. Significant exercise effects, i.e. differences between EG and CG, present after 13 months of exercise, were lost after 3 months of detraining for LBM (p = 0.157) and BMD-LS (p = 0.065), but not for strength (p < 0.001) and power (p < 0.001). Of note, self-reported individual outdoor activities and exercise increased by about 40% in both groups during the lock-down period. Three months' absence from a supervised group exercise protocol resulted in considerable detraining effects for musculoskeletal parameters. Thus, exercise programs for adults should be continuous rather than intermittent.Trial registration number: ClinicalTrials.gov: NCT04420806, 06.05.2020.

Changes in Body Composition and Cardiometabolic Health After Detraining in Older Men with Osteosarcopenia: 6-Month Follow-Up of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST) Study

Purpose

Temporary cessation of exercise but maintenance of habitual physical activity might be a frequent situation in older people’s lives. Particularly the COVID-19 induced lockdown of exercise training facilities with individual outdoor activities still being allowed might be a blueprint for this potentially harmful scenario. Thus, the aim of the present study was to determine the effects of 6 months of detraining after 18 months of high-intensity resistance exercise (HIT-RT) on body composition and cardiometabolic outcomes in predominately obese older men with osteosarcopenia.

Materials and Methods

Community-dwelling predominately obese men 72–91 years old with low muscle and bone mass (n=43) were randomly assigned to an 18-month HIT-RT (EG: n=21) or a non-training control group (CG, n=22). After the intervention, participants of the EG discontinued HIT-RT for 6 months, but increased their habitual physical activity. Study outcomes were group differences in detraining changes (“effects”) for lean body mass (LBM), total and abdominal body fat rate (determined by dual-energy x-ray absorptiometry) and the Metabolic Syndrome Z-Score (MetSZ). We applied an intention-to-treat analysis with multiple imputation to analyze the data.

Results

After the 18-month HIT-RT, we observed significant positive training effects for LBM, total and abdominal body fat rate and the MetSZ (all p<0.001). Abrupt cessation of HIT-RT for 6 months resulted in significantly higher unfavorable changes in the HIT-RT compared with the CG for LBM (p=0.001), total body fat (p=0.003) and the MetSZ (p=0.003), apart from abdominal body fat (p=0.059). However, significant overall effects were still present after 24 months for LBM and body fat indices but not for the MetSZ.

Conclusion

The present study clearly indicates the unfavorable effects of 6 months of detraining after HIT-RT. Correspondingly, exercise protocols particularly for older people should focus on continuous exercise with short regeneration periods rather than on intermitted protocols with pronounced training breaks.

Detraining effects after 18 months of high intensity resistance training on osteosarcopenia in older men-Six-month follow-up of the randomized controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

PURPOSE

Detraining after dedicated exercise programs might be a frequent situation in older people's exercise patterns. The aim of the present study was thus to determine the effects of 6 months of detraining after 18 months of high intensity resistance exercise (HIT-RT) on musculoskeletal outcomes in older men with sarcopenia.

METHODS

Community-dwelling men aged 72 years and older with osteosarcopenia (n = 43) were randomly assigned to an 18-month HIT-RT (EG: n = 21) or a non-training control group (CG, n = 22). After the intervention, participants of the EG stopped HIT-RT for 6 months, but continued their habitual physical activity. Study outcomes were skeletal muscle mass index, bone mineral density (BMD) at the lumbar-spine and total-hip, maximum hip/leg-extensor strength, handgrip strength and gait velocity. We applied an intention-to-treat analysis with multiple imputation.

RESULTS

Changes in the HIT-RT were much more pronounced during the detraining period compared with the CG, although this effect was only significant for skeletal muscle mass index and hip-/leg-extensor strength (p = .002 and p = .013), but not for lumbar-spine BMD (p = .068), total-hip BMD (p = .069), handgrip strength (p = .066) or gait velocity (p = .067). Apart from total-hip BMD (p = .055), handgrip strength (p = .069) and gait velocity (p = .881) values of the HIT-RT group decreased significantly during detraining. However, after 24 months, overall effects (p < .001) were still observed for skeletal muscle mass index and hip-/leg-extensor strength.

CONCLUSION

Although unable to state from which point in time relevant detraining effects emerge, we conclude that health care providers should focus on continuous rather than intermitted exercise programs for older people. Clinical trial number: clinicalTrials.gov: NCT03453463; NCT04444661.

The impact of 2 weeks of detraining on phase angle, BIVA patterns, and muscle strength in trained older adults

BACKGROUND

An intermission in the training routine, in which older adults refrain from regular structured exercise, may have deleterious effects on muscle performance and bioelectric phase angle (PhA), which is a predictive marker for cellular integrity.

PURPOSE

To determine the effects of a 2-week detraining period on PhA and muscular strength (MS) in trained older adults.

METHODS

A total of 14 trained older adults (6 females) aged ≥65 years (77.2 ± 6.6) were assessed at baseline (i.e. trained condition) and after 2 weeks of detraining, where they refrained from their usual participation in structured exercise sessions. Whole-body resistance (R), reactance (Xc), and PhA were assessed using bioelectrical impedance analysis (BIA, single frequency, 50 kHz ± 1%, NutriLab, Akern). MS was assessed on both lower and upper limbs under isometric conditions. Differences between moments were examined using ANOVA for repeated measures, while adjusting for sex. Bioimpedance vector analysis (BIVA) was performed to evaluate changes in cellular function and body fluid content.

RESULTS

Detraining resulted in declines in PhA (-4.34%) (p = 0.017). There was a significant difference in the mean impedance vectors from baseline to post-detraining (p < 0.05), which were driven by decreases in reactance (Xc) relative to height (Xc/H) with little change in resistance (R) relative to height (R/H) for both males and females. No differences were found in MS for both the leg press (p = 0.992) and bench press (p = 0.166) tests.

CONCLUSION

A detraining period as short as 2-weeks is enough to cause alterations in the bodies bioelectrical properties, resulting in detrimental changes in PhA, due to alterations in cellular integrity, but not in MS. These results highlight the importance of maintaining structured exercise sessions in older adults, and reinforce the potential role of PhA as a sensitive predictor to detect acute changes in muscle cell integrity following alterations in exercise training.

MRI and CT Assessment of Abdominal Tissue Composition in Patients After High-Intensity Focused Electromagnetic Therapy Treatments: One-Year Follow-Up

BACKGROUND

Several studies investigating high-intensity focused electromagnetic (HIFEM) treatments have recently been published. However, due to the novelty of the procedure, long-term data are still missing.

OBJECTIVES

The aim of this study was to evaluate changes in abdominal tissues on average 1 year after a series of HIFEM treatments, to determine the long-term durability of patients' original body responses.

METHODS

Magnetic resonance imaging (MRI) or computed tomography (CT) scanning were performed on 21 patients a mean of 332.6 [88.5] days after their original HIFEM treatment series. The scans were evaluated by a blinded radiologist for abdominal muscle thickness, subcutaneous fat changes, and abdominal separation. The results were compared with the MRI/CT-assisted measurements taken at baseline and 6-week follow-up. Correlations between collected data sets were calculated and tested. The incidence of any adverse events related to earlier treatments was monitored.

RESULTS

When comparing the 1-year follow-up measurements with the baseline, the MRI/CT-assisted calculations revealed mean reductions of 14.63% (2.97 [2.11] mm) in fat, 19.05% (1.89 [0.88] mm) in muscle thickening, and 10.46% (1.96 [1.71] mm) in diastasis recti. All changes were significant (P < 0.05) and not related to weight fluctuations (P > 0.05). The baseline width of diastasis positively correlated with the degree of improvement at follow-up. No adverse events were reported.

CONCLUSION

The HIFEM-induced muscle hypertrophy, fat reduction, and reduction in abdominal separation were maintained 1-year posttreatment. This suggests long-term durability of the original bodily response, which needs to be verified by continuing follow-up of this group and by further studies.

LEVEL OF EVIDENCE: 4

Role of Nutrition and Exercise Programs in Reducing Blood Pressure: A Systematic Review

The combined effect of diet and strength training (ST) on blood pressure (BP) seems to be very important for the treatment of prehypertension and hypertension (HT). Therefore, the aim of this study was to determine whether ST alone or combined with nutrition or supplementation has an impact on the arterial pressure reduction in normotensive and hypertensive populations. A systematic computerized literature search was performed according to the PRISMA guidelines using PubMed, Scopus and Google Scholar; only English language studies published from 1999 until 2018 were included. This systematic search identified the results of 303 individuals from nine studies. The ST program alone had a similar effectiveness as the nutrition program (NP) alone; however, their combination did not result in increased effectiveness in terms of a high BP reduction. The consumption of L-citrulline had a similar effect as ST on lowering BP; on the other hand, caffeine led to an increase in BP during the ST session. Our data suggest that a combination of ST 2-3 times a week at moderate intensity and a NP seems to be equally effective in terms of lowering BP (systolic and diastolic) as ST and NP alone.

Effect of resistance training with different frequencies and subsequent detraining on muscle mass and appendicular lean soft tissue, IGF-1, and testosterone in older women

OBJECTIVE

To analyse the effect of resistance training (RT) frequency on muscle mass, appendicular lean soft tissue, insulin-like growth factor 1 (IGF-1), testosterone, and their changes with detraining in older women.

METHODS

Forty-five physically independent older women (≥ 60 years) were randomly assigned to perform RT either two (G2X, n = 21) or three times/week (G3X, n = 24), during 12 weeks (8 exercises, 1 set of 10-15 repetition maximum). Muscle mass and appendicular lean soft tissue, IGF-1, testosterone, and dietary intake were measured at pre-training, post-training, and after detraining (12 weeks).

RESULTS

Muscle mass and appendicular lean soft tissue significantly increased post-training (G2X = +5.5% and G3X = +5.8%, P < .0001) with no differences between groups, and gains were retained after detraining (G2X = 100% and G3X = 99%, P < .0001). IGF-1 and dietary intake did not change for the groups during the study. Testosterone did not change post-training but significantly decreased after detraining (G2X = -21% and G3X = -50%, P < .0001).

CONCLUSION

We conclude that lower RT frequency is as effective as higher frequency to improve muscle mass and appendicular lean soft tissue, and to maintain testosterone and IGF-1. Additionally, detraining may reduce testosterone regardless of RT frequency. These results are specifically for community-dwelling older women and may not be generalized to other populations.

Four-Week Unstructured Break Improved Athletic Performance in Collegiate Rugby Players

Jensen, CD, Gleason, D, and VanNess, JM. Four-week unstructured break improved athletic performance in collegiate rugby players. J Strength Cond Res 32(6): 1671-1677, 2018-This study analyzed the changes in athletic performance and anthropometric characteristics in collegiate male club rugby athletes (n = 14) after a 4-week winter break. All measurements were collected before and after the break. Body composition was assessed by body mass index and hydrostatic weighing. Performance measurements were as follows: V[Combining Dot Above]O2max, vertical jump, 10-yard sprint, squat max, and bench press max. Before testing, each subject was acclimated to the protocols to reduce learning effects. During the 4-week break, no workouts were provided for the athletes; it was unsupervised and unstructured. Participants were required to maintain and submit self-reported nutritional and activity logs during this period. After the break, the athletes demonstrated a 5.0% improvement in V[Combining Dot Above]O2max (absolute increase of 2.25 ml·kg·min), 6.8% improvement in vertical jump (1.50 inches), and a 14.3% increase in squat max (38.64 lb). Although increases in body mass (1.0%) were not significant, the body fat percentage exhibited a relative increase of 19.3% (absolute change from 13.35 to 15.93%). A significant discriminate function analysis indicated statistical differences between groups based on these variables. Self-reported behavior logs confirmed participation in >3 days of moderate to intense physical activity per week but somewhat poor dietary habits. These results indicate that collegiate rugby athletes may not need prescribed exercise routines during seasonal breaks in the athletic schedule. However, it may be beneficial to provide structured nutritional advice during unsupervised periods.

Effects of a short-term detraining period on muscle functionality and cognition of strength-trained older women: a preliminary report

The present study aimed to investigate the impact of a 1-month detraining composed by Christmas and New Year’s Day in the functional and cognitive parameters of 12 older women who had previously participated in 22-week moderate intensity strength training program (ST; n=6) or remained performing their regular habits of life during all study period, without engaging in physical exercise programs (CG; n=6). Transfer capacity (i.e., Timed Up and Go [TUG]) and executive function (i.e., TUG with a cognitive task) were increased in the ST group after the intervention. However, the 1-month detraining period was enough to totally reverse the gains in both parameters. In conclusion, data of the present study indicate that 1 month of detraining was enough to totally reverse the beneficial effects of a 6-month ST program on physical mobility and executive function of older women.

Training load does not affect detraining's effect on muscle volume, muscle strength and functional capacity among older adults

Research underlines the potential of low-load resistance exercise in older adults. However, while the effects of detraining from high-load protocols have been established, it is not known whether gains from low-load training would be better/worse maintained. The current study evaluated the effects of 24weeks of detraining that followed 12weeks of high- and low-load resistance exercise in older adults. Fifty-six older adults (68.0±5.0years) were randomly assigned to leg press and leg extension training at either HIGH load (2×10-15 repetitions at 80% of one-repetition maximum (1-RM)), LOW load (1×80-100 repetitions at 20% of 1-RM), or LOW+ load (1×60 repetitions at 20% of 1-RM, immediately followed by 1×10-20 repetitions at 40% 1-RM). All protocols ended with volitional fatigue. The main outcome measures included mid-thigh muscle volume, leg press 1-RM, leg extension isometric and isokinetic strength, and functional performance. Tests were performed at baseline, post-intervention and after 24weeks of detraining. Results show no effect of load on preservation of muscle volume, which returned to baseline after detraining. Training-induced gains in functional capacity and isometric strength were maintained, independent of load. HIGH and LOW+ were more beneficial than LOW for long-lasting gains in training-specific 1-RM. To conclude, gains in muscle volume are reversed after 24weeks of detraining, independent of load. This emphasises the need for long-term resistance exercise adherence. The magnitude of detraining in neuromuscular and functional adaptations was similar between groups. These findings underline the value of low-load resistance exercise in older age. Clinical Trial Registration NCT01707017.

Resistance Training-Induced Elevations in Muscular Strength in Trained Men Are Maintained After 2 Weeks of Detraining and Not Differentially Affected by Whey Protein Supplementation

Hwang, PS, Andre, TL, McKinley-Barnard, SK, Morales Marroquín, FE, Gann, JJ, Song, JJ, and Willoughby, DS. Resistance training-induced elevations in muscular strength in trained men are maintained after 2 weeks of detraining and not differentially affected by whey protein supplementation. J Strength Cond Res 31(4): 869-881, 2017-Resistance training (RT) with nutritional strategies incorporating whey protein intake postexercise can stimulate muscle protein synthesis and elicit hypertrophy. The early phases of training-induced anabolic responses can be attenuated with longer-term training. It is currently unknown if short-term detraining (DT) can restore these blunted anabolic responses during a subsequent retraining (ReT) period. Twenty resistance-trained men (age 20.95 ± 1.23 years; n = 20) were randomized into one of 2 groups (PRO or CHO; 25 g) in a double-blind manner. Participants followed a 4-day per week RT program (4-week RT; 2-week DT; 4-week ReT) while consuming their respective supplement only on workout days during RT and ReT, but every day during DT. At baseline, 4 weeks after RT (post-RT), 2 weeks after DT (post-2-week DT), and after 4 weeks of ReT after DT (post-ReT), leg press strength (LPS) was assessed and rectus femoris cross-sectional area and lean mass changes were assessed by ultrasonography and dual-energy x-ray absorptiometry, respectively. A factorial 2 × 4 (group by time) analyses of variance with repeated measures were used with a probability level at ≤0.05. LPS was elevated throughout the 10-week training study (p = 0.003) with no decrease in LPS after DT in both groups. Although not statistically significant, both groups retained lean mass after DT. A 2-week period of DT appeared to retain muscular strength in resistance-trained men. Therefore, a short-term period of DT can potentially retain lower-body strength in young resistance-trained men irrespective of supplementing with 25 g of whey protein postexercise.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: five-year results from a double-blind, randomized controlled trial

BACKGROUND

The aim of this study was to compare the 5-year survival and success rates of 3.3 mm dental implants either made from titanium-zirconium (TiZr) alloy or from Grade IV titanium (Ti Grade IV) in mandibular implant-based removable overdentures.

METHODS

The core study had a follow-up period of 36 months and was designed as a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann Bone Level implants (diameter 3.3 mm, SLActive®), one of TiZr (test) and one of Ti Grade IV (control), in the interforaminal region. This follow-up study recruited patients from the core study and evaluated the plaque and sulcus bleeding indices, radiographic crestal bone level, as well as implant survival and success 60 months after implant placement.

RESULTS

Of the 91 patients who initially received implants, 75 completed the 36 month follow-up and 49 were available for the 60 month examination. Two patients were excluded so that a total of 47 patients with an average age of 72 ± 8 years were analysed. The characteristics and 36-month performance of the present study cohort did not differ from the non-included initial participants (p > 0.05). In the period since the 36-month follow-up examination, no implant was lost. The cumulative implant survival rate was 98.9 % for the TiZr group and 97.8 % for the Ti Grade IV group. Crestal bone level changes at 60 months were not different in the test and control group (TiZr -0.60 ± 0.69 mm and Ti Grade IV -0.61 ± 0.83 mm; p = 0.96). The cumulative implant success rate after 60 months was 95.8 and 92.6 % for TiZr and Ti Grade IV, respectively.

CONCLUSIONS

After 60 months, the positive outcomes of the 36 month results for TiZr and Ti Grade IV implants were confirmed, with no significant differences with regard to crestal bone level change, clinical parameters and survival or success rates. TiZr implants performed equally well compared to conventional Ti Grade IV 3.3 mm diameter-reduced implants for mandibular removable overdentures.

TRIAL REGISTRATION

Registered on www.clinicaltrials.gov: NCT01878331.

Effects of detraining after blood flow-restricted low-load elastic band training on muscle size and arterial stiffness in older women

Background

We examined the effects of detraining after blood flow-restricted (BFR) low-load elastic band training on muscle size and arterial stiffness in older women.

Findings

Fourteen women were divided into BFR training (BFR-T) or non-BFR training (CON-T). Each group participated in 12 weeks of arm curl and press down training using an elastic band either with (BFR-T) or without BFR (CON-T). Muscle cross-sectional area (CSA) and maximum voluntary isometric contraction (MVIC) for upper arms and cardio-ankle vascular index (CAVI) were evaluated before and after the 12-week training period and also after 12 weeks of detraining. CSA and MVIC were higher at post and detraining (CSA: 16.3% (p < 0.01) and 6.9% (p < 0.01) for elbow flexion and 17.1% (p < 0.01) and 8.7% (p > 0.05) for elbow extension; MVIC: 7.3 and 3.9% (both p > 0.05) for elbow flexion and 17.6 and 15.1% (both p < 0.01) for elbow extension) than at pre for the BFR-T, but not for the CON-T. There was no change in CAVI for the two groups.

Conclusions

Increased muscle strength/size following 12 weeks of elastic band BFR-T was well maintained with a low risk of arterial stiffness after 12 weeks of detraining in older women.

Effects of a Multimodal Exercise Program on Physical Function, Falls, and Injuries in Older Women: A 2-Year Community-Based, Randomized Controlled Trial

OBJECTIVES

To investigate the effects of multimodal supervised exercise on physical functioning, falls, and related injuries in older women.

DESIGN

Two-year randomized controlled trial.

SETTING

Tampere, Finland.

PARTICIPANTS

Women aged 70 to 80 who had fallen in the previous year (n = 409).

INTERVENTION

Participants were randomly assigned to an exercise or control group (ClinicalTrial.gov NCT00986466). Exercisers participated in group exercise classes twice a week for 12 months and once a week for the subsequent 12 months and home exercises. Controls maintained their current physical activity.

MEASUREMENTS

Physical functioning assessed at baseline and at 6-month intervals during the intervention. Falls and related injuries monitored with fall diaries.

RESULTS

Intention-to-treat analyses showed that exercise led to significant improvements in physical functioning. Leg strength differed significantly between the groups (mean change: 14.1%, 95% confidence interval (CI) = 8.0 to 20.2 in exercisers; 1.6%, 95% CI = -4.5 to 7.7 in controls; P < .001). Chair stand time also differed significantly between groups (7.4%, 95% CI 3.8 to 10.8% in exercisers; 2.4%, 95% CI = -1.6 to 6.2) in controls; P = .02). Between-group differences were significant for fast walking speed (P = .003) and probability of completing the backward walking test (P < .001), favoring exercisers. Timed Up-and-Go and grip strength did not differ between groups. There was no difference in the total falls incidence rate ratio (IRR = 1.0, 95% CI = 0.79 to 1.26), but exercisers were less likely to have medically attended injurious falls (IRR = 0.45, 95% CI = 0.27 to 0.78; P = .004).

CONCLUSION

Twenty-four months of multimodal exercise enhanced physical functioning in women aged 70 to 80 with a history of falls. Although the total number of falls was not lower than in controls, the rate of medically attended injurious falls was more than 50% lower.

Effects of detraining after blood flow-restricted low-intensity concentric or eccentric training on muscle size and strength

We investigated the effects of 6 weeks of detraining on muscle size and strength in young men who had previously participated in 6 weeks (3 days/week) of 30 % of concentric one-repetition maximal (1-RM) dumbbell curl training [one arm: concentric blood flow restricted (BFR) exercise (CON-BFR); the other arm: eccentric BFR exercise (ECC-BFR)]. MRI-measured muscle cross-sectional area (CSA) at 10 cm above the elbow joint increased from pre to post (p < 0.01), and the muscle CSA following detraining remained greater than pre (p < 0.01) but was similar to that observed at post. Maximal voluntary contraction (MVC) increased from pre to post (p < 0.05), and the MVC following detraining remained greater than pre (p < 0.05) but was similar to that observed at post. The ECC-BFR did not produce any changes across time. Increased muscle strength following 6 weeks of CON-BFR was well preserved at 6 weeks of detraining, which may be primarily related to muscle hypertrophy.

Effects of detraining after blood flow-restricted low-intensity training on muscle size and strength in older adults

BACKGROUND

Although blood flow-restricted low-intensity resistance training (BFR-RT) increases muscle size and strength in older adults, the effect of detraining on muscle adaptation is unclear.

METHODS

We investigated the effects of 24 weeks of detraining on thigh muscle cross-sectional area (CSA) and one-repetition maximum strength (1-RM) in older adults who had previously participated in 12 weeks of training (BFR-RT, 20-30 % 1-RM, knee extension and leg press) or non-BFR training.

RESULTS

Both 1-RM and relative dynamic strengths (1-RM divided by quadriceps femoris (QF) muscle CSA) were higher at both post-training and detraining than at pre-training for the BFR-RT group (p < 0.05). QF muscle CSA was higher at only post-training than at pre-training for the BFR-RT group (p < 0.01).

CONCLUSION

Increased muscle strength following 12 weeks of training with BFR-RT was well preserved at 24 weeks of detraining, which is due mainly to neural adaptation in older adults.

Impact of range of motion during ecologically valid resistance training protocols on muscle size, subcutaneous fat, and strength

The impact of using different resistance training (RT) kinematics, which therefore alters RT mechanics, and their subsequent effect on adaptations remain largely unreported. The aim of this study was to identify the differences to training at a longer (LR) compared with a shorter (SR) range of motion (ROM) and the time course of any changes during detraining. Recreationally active participants in LR (aged 19 ± 2.6 years; n = 8) and SR (aged 19 ± 3.4 years; n = 8) groups undertook 8 weeks of RT and 4 weeks of detraining. Muscle size, architecture, subcutaneous fat, and strength were measured at weeks 0, 8, 10, and 12 (repeated measures). A control group (aged 23 ± 2.4 years; n = 10) was also monitored during this period. Significant (p > 0.05) posttraining differences existed in strength (on average 4 ± 2 vs. 18 ± 2%), distal anatomical cross-sectional area (59 ± 15 vs. 16 ± 10%), fascicle length (23 ± 5 vs. 10 ± 2%), and subcutaneous fat (22 ± 8 vs. 5 ± 2%), with LR exhibiting greater adaptations than SR. Detraining resulted in significant (p > 0.05) deteriorations in all muscle parameters measured in both groups, with the SR group experiencing a more rapid relative loss of postexercise increases in strength than that experienced by the LR group (p > 0.05). Greater morphological and architectural RT adaptations in the LR (owing to higher mechanical stress) result in a more significant increase in strength compared with that of the SR. The practical implications for this body of work follow that LR should be observed in RT where increased muscle strength and size are the objective, because we demonstrate here that ROM should not be compromised for greater external loading.

The training and detraining effects of 8 weeks of water exercise on obstacle avoidance in gait by the elderly

[Purpose] This study aimed to provide useful information for fall prevention for the elderly by investigating how safely the elderly cross an obstacle after 8 weeks water exercise, and how much of the training effect remained 8 weeks after finishing the exercise. [Subjects] Eleven elderly participants participated in this study. [Methods] To identify the training and detraining effect of 8 weeks of water exercise, a 3-D motion analysis with 7 infrared cameras and one force plate, was performed. [Results] In most of all variables, statistically significant training and detraining effects at obstacle heights of 30% leg length were found. At obstacle heights of 40% leg length, statistically significant training effects were found but only improvement pattern of detraining effects were found for all variables. [Conclusion] The findings of this study indicate that 8 weeks of water exercise at the level of RPE 12-13 may help the elderly to safely cross obstacles at the most common height associated with falls (30% of leg length) for at least 8 weeks after training termination. The training effect, however, should not be expected to last for 8 weeks after the training at obstacle heights of 40% height of their leg length, which is a more difficult height for the elderly to cross.

Effects of short-term detraining following blood flow restricted low-intensity training on muscle size and strength

We investigated the effects of 3 weeks of detraining on muscle cross-sectional area (CSA) and one-repetition maximum strength (1-RM) in young men who had previously participated in 6 weeks (3 days week(-1) ) of bench press training [blood flow restricted low-intensity (LI-BFR; n = 10, 20% 1-RM) or high-intensity (HI; n = 7, 75% 1-RM)]. Bench press 1-RM and muscle CSA of triceps brachii (TB) and pectoralis major (PM) were evaluated before (pre) and after training period (post) as well as after detraining period (detraining). Bench press 1-RM was higher at both post and detraining than at pre for LI-BFR (P<0·01) and the HI (P<0·01). TB and PM muscle CSA were higher at both post and detraining than at pre for the HI group (P<0·01), while the LI-BFR group only increased (P<0·01) at post. Relative dynamic strength (1-RM divided by TB muscle CSA) was higher at both post and detraining than at pre for the HI group (P<0·01), while the LI-BFR group only increased (P<0·01) at detraining. In conclusion, increased muscle strength following 6 weeks of training with LI-BFR as well as HI was well preserved at 3 weeks of detraining. HI-induced muscle strength appears to be dependent upon both neural adaptations and muscle hypertrophy with training and detraining. On the other hand, LI-BFR-induced muscle strength appears to be related primarily to muscle hypertrophy with training and to neural adaptations with detraining.

Sustained effect of resistance training on blood pressure and hand grip strength following a detraining period in elderly hypertensive women: a pilot study

INTRODUCTION

Hypertension is the most prevalent modifiable risk factor with a high prevalence among older adults. Exercise is a nonpharmacological treatment shown to benefit all patients with hypertension.

OBJECTIVE

This study examined the effects of a 14-week moderate intensity resistance training program (RT) on the maintenance of blood pressure and hand grip strength during an extended detraining period in elderly hypertensive women.

METHODS

Twelve hypertensive sedentary elderly women completed 14 weeks of whole body RT at a moderate perceived exertion following a detraining period of 14 weeks.

RESULTS

Following the training period, participants demonstrated an increase in absolute hand grip strength (P=0.001), relative hand grip strength (P=0.032) and a decrease of systolic (P=0.001), diastolic (P=0.008), and mean blood pressure (P=0.002) when compared to pre-exercise values. In addition, these effects were sustained after 14 weeks of detraining.

CONCLUSION

Resistance training may be a valuable method to improve muscular strength and blood pressure in elderly people with benefits being maintained up to 14 weeks following training cessation.

Implant-supported mandibular overdentures in very old adults: a randomized controlled trial

The purpose of this study was (1) to investigate denture satisfaction following the conversion of existing mandibular complete dentures to implant overdentures (IOD) in very old edentulous patients who depend on help for activities of daily living and (2) to evaluate secondary end points, such as functional, structural, nutritional, and patient-centered aspects. For this randomized clinical trial, 2 interforaminal short implants were placed in the intervention group (n = 16, 85.0 ± 6.19 yrs) to retain mandibular IODs; the control group (n = 18, 84.1 ± 5.55 yrs) received conventional relines. During the first year, no implant was lost; however, 2 patients died. IODs proved more stable, and participants in the intervention group demonstrated significantly higher denture satisfaction as well as an increased oral health-related quality of life compared to the control group. Maximum voluntary bite force improved significantly with IODs, yet the chewing efficiency was not different between groups. Masseter muscle thickness increased with IODs, mainly on the preferred chewing side. Body mass index decreased in both groups, but the decline tended to be smaller in the intervention group; blood markers and the Mini Nutritional Assessment did not confirm this tendency. These results indicate that edentulous patients who depend on help for activities of daily living may benefit from IODs even late in life.

Exercise dosing to retain resistance training adaptations in young and older adults

Resistance training (RT) is a proven sarcopenia countermeasure with a high degree of potency. However, sustainability remains a major issue that could limit the appeal of RT as a therapeutic approach without well-defined dosing requirements to maintain gains.

PURPOSE

To test the efficacy of two maintenance prescriptions on muscle mass, myofiber size and type distribution, and strength. We hypothesized the minimum dose required to maintain RT-induced adaptations would be greater in the old (60-75 yr) versus young (20-35 yr).

METHODS

Seventy adults participated in a two-phase exercise trial that consisted of RT 3 d·wk for 16 wk (phase 1) followed by a 32-wk period (phase 2) with random assignment to detraining or one of two maintenance prescriptions (reducing the dose to one-third or one-ninth of that during phase 1).

RESULTS

Phase 1 resulted in expected gains in strength, myofiber size, and muscle mass along with the typical IIx-to-IIa shift in myofiber-type distribution. Both maintenance prescriptions preserved phase 1 muscle hypertrophy in the young but not the old. In fact, the one-third maintenance dose led to additional myofiber hypertrophy in the young. In both age groups, detraining reversed the phase 1 IIx-to-IIa myofiber-type shift, whereas a dose response was evident during maintenance training with the one-third dose better maintaining the shift. Strength gained during phase 1 was largely retained throughout detraining with only a slight reduction at the final time point.

CONCLUSIONS

We conclude that older adults require a higher dose of weekly loading than the young to maintain myofiber hypertrophy attained during a progressive RT program, yet gains in specific strength among older adults were well preserved and remained at or above levels of the untrained young.