Effect of combined aerobic-resistance training and subsequent detraining on brain-derived neurotrophic factor (BDNF) and depression in women with type 2 diabetes mellitus: A randomized controlled trial.

AIMS: In this study, we assessed the effects of a 12-week combined aerobic-resistance training and subsequent detraining on Beck Depression Inventory (BDI) score and mediating role of BDNF and also investigated whether exercise-induced alterations are maintained following a short period of detraining in women with type 2 diabetes (T2D). MATERIALS AND METHODS: Thirty-four women with T2D were randomly assigned to experimental or control group (age: 60.6 ± 6.3, body mass index (BMI): 30.2 ± 1.3 kg/m2 , HbA1c: 8.09 ± 0.73%). The exercise training comprised of combined aerobic-resistance programme (50%-70% heart rate reserve for aerobic exercise, and 50%-70% 1 repetition maximum for resistance exercise, respectively) performed three sessions per week over 12 weeks. The intervention period was followed by an 8-week detraining period. Data were collected at baseline and also following exercise intervention and detraining. Data were analysed by linear mixed model at p < 0.05. RESULTS: After 12 weeks of combined exercise training and 8 weeks of detraining, there was a significant difference in BDNF (0.08; 95% confidence interval [CI] = 0.07-0.10; p = 0.001), fasting blood glucose (FBG) (-45.41; CI = -50.83, -39.98; p = 0.001), insulin (-6.47; CI = -7.04, -5.9; p = 0.001), HOMA-IR (-3.76; CI = -4.07, -3.45; p = 0.001) and BDI score (-17.17; CI = -20.29, -14.05; p = 0.001) between the experimental and control group. Multiple mediation analysis indicated that BDNF seems to have a mediating role in exercise-induced improvement of depression (p = 0.04). After the detraining period, BDI score remained unchanged and it showed a significant increase compared to before the start of training (p = 0.001). CONCLUSIONS: It may be concluded that exercise training improves depression that is likely to be explained by increased BDNF concentration in TD2. In spite of decreased BDNF concentration following an 8-week detraining, depression score was maintained.

Long-Term Effects of a 6-Week Power-Based Resistance Training and Fast Walking Interval Training Program on Physical Function, Muscle Power, Disability, and Frailty in Pre-Frail and Frail Older Adults.

INTRODUCTION: Concurrent training has been shown to be a beneficial approach to improve overall health status in older adults. However, little is known about the adaptations of this type of training in the long term (i.e., after cessation of exercise), even less in older people affected by frailty syndrome. Therefore, this study aimed (i) to assess the effects of a 6-week concurrent training program composed of power-oriented resistance training and fast walking interval training on physical function, muscle power, disability in activities of daily living and frailty in pre-frail and frail older people, and (ii) to assess the effects of a 6-month detraining period on these outcomes. METHODS: A total of 59 pre-frail and frail older adults (>75 years old; Frailty Phenotype >1) were allocated into intervention (INT; n = 32; 81.8 years; 21 women) or control (CON; n = 27; 82.5 years; 19 women) groups. Primary outcomes of this study were Short Physical Performance Battery (SPPB), relative sit-to-stand (STS) power, Barthel index, Lawton scale and Frailty Phenotype. Assessments were performed at baseline (PRE), after the concurrent training programme (POST) and after 6 months of follow-up (DET) in both groups. Mixed model repeated measures ANOVA with Bonferroni's post hoc tests was used. RESULTS: Immediately after the intervention (∆ = POST-PRE), INT improved SPPB (∆ = 3.0 points; p < 0.001), relative STS power (∆ = 0.87 W·kg-1; p < 0.001) and reduced their frailty levels (∆ = -1.42 criteria; p < 0.001), while no changes were observed in CON. After 6 months of detraining (∆ = DET-PRE), INT showed higher SPPB (∆ = 2.2 points; p < 0.001), higher relative STS power (∆ = 0.73 W·kg-1; p < 0.001) and lower frailty (∆ = -1.24 criteria; p < 0.001) values than those reported at baseline, which were significantly different than those reported by CON. Both, Barthel index and Lawton scale values were not modified during the study in either group. CONCLUSIONS: The 6-week concurrent training program improved physical function, muscle power and reduced frailty in pre-frail and frail older people and these improvements were maintained above baseline levels after 6 months of detraining. However, due to the individual variability found, future studies of long-term responders versus non-responders in frail populations are required.

The effects of high-intensity interval training/moderate-intensity continuous training on the inhibition of fat accumulation in rats fed a high-fat diet during training and detraining.

BACKGROUND: Compared with moderate-intensity continuous training (MICT), high-intensity interval training (HIIT) has at least a comparable effect on inhibiting an increase in fat. However, few studies have been conducted to examine the effects of detraining on body fat in rats fed a high-fat diet. The present study aimed to compare the effects of 10 weeks of HIIT or MICT as well as 6 weeks of detraining on body fat in rats fed a high-fat diet. METHODS: After being fed a high-fat diet for 8 weeks, 54 female rats were randomly assigned to six groups: (1) CON-10, sedentary control for 10 weeks; (2) MICT-10, 10 weeks of MICT; (3) HIIT-10, 10 weeks of HIIT; (4) CON-16, sedentary control for 16 weeks; (5) MICT-16, 10 weeks of MICT followed by 6 weeks of training cessation; and (6) HIIT-16, 10 weeks of HIIT followed by 6 weeks of training cessation. The training was performed 5 days/week. The subcutaneous adipose tissue (inguinal; SCAT), visceral adipose tissue (periuterine; VAT) and serum lipid profile were analysed after 10 or 16 weeks. Adipose tissue triglyceride lipase (ATGL) protein expression in VAT was assessed by western blotting. RESULTS: HIIT-10 and MICT-10 prevented the increase in SCAT, VAT and serum lipid levels seen in the CON group. During the 6-week detraining period, HIIT continued to prevent the increase in adipose tissue mass observed in the CON group, whereas MICT at least maintained this inhibition. The inhibition of fat mass increase was mainly the result of preventing adipocyte hypertrophy. The HIIT-10 and HIIT-16 groups showed the highest ATGL protein expression. CONCLUSIONS: HIIT has a comparable effect to MICT on inhibiting fat accumulation in female rats; however, the inhibition of SCAT and VAT increase by HIIT is superior to MICT after short-term training cessation.

Biceps femoris long head stiffens after 2 weeks of training cessation in highly trained sprinters.

PURPOSE: Most athletes experience short-term training cessation because of illness, injury, post-season vacation, or other reasons. Passive muscle stiffness is a potential risk factor for a sprint-type hamstring strain injury, but limited information is available about the effect of short-term training cessation on passive muscle stiffness. The present study aimed to identify whether and how passive muscle stiffness of the biceps femoris long head (BFlh) would vary due to 2 weeks of training cessation in sprinters. METHODS: Passive BFlh shear-wave speed (a proxy for stiffness) was measured using ultrasound shear-wave elastography in 28 male sprinters, before and after 2 weeks of intervention. During the 2 weeks, the participants in the training-cessation group (n = 14) were allowed to maintain their normal daily activities but not to perform any physical training, including stretching and resistance exercises. The participants in the training continuation group (n = 14) performed the training (including maximum speed sprint, plyometric, and weight training) prescribed by their coaches 5 days per week. RESULTS: In the training-cessation group, passive BFlh shear-wave speed increased after the 2 weeks of training cessation (4.75 ± 0.77 to 5.00 ± 0.88 m/s, P < 0.001). In contrast, there was no significant difference before and after the 2 weeks of training continuation (4.90 ± 0.85 to 4.93 ± 0.85 m/s, P = 0.521). CONCLUSIONS: The present findings indicate that muscles stiffen by training cessation in sprinting athletes.

Extensive Familiarization Is Required Before Assessing Acute Changes in Multiple Object Tracking Performance.

CONTEXT: The Neurotracker CORE assessment is an 8-minute multiple object tracking (MOT) program used in sport science research and clinical rehabilitation as a perceptual-cognitive training tool; however, it has garnered interest for its potential use as an acute assessment of cognitive performance. Although some data exist regarding the learning effect of repeated exposures, it is often overlooked with investigators focusing primarily on the presence of transfer effects to other cognitive realms. As a result, exclusive data on the effect of repeated testing, or subsequent periods of no testing (ie, detraining) on test-retest reliability, and on MOT performance are sparse. DESIGN: Repeated-measures/reliability. METHODS: Twenty-three recreationally active men and women completed 15 training sessions consisting of 2 CORE assessments per session (30 assessments). Participants were randomized to either 1 or 2 weeks of detraining prior to completing 15 retraining sessions (30 assessments). Training and retraining periods were divided into 10 blocks (3 assessments/block) for analysis. MOT speed threshold (MOT-ST), consistency, fastest trial score success speed, lowest trial score miss speed, the number of perfect, near misses, and significant miss trials within each block were used to determine performance. Intraclass correlation coefficient, standard error of measurement, and minimal detectable change were used to determine reliability. RESULTS: Significant improvements in MOT-ST and fastest trial score success speed were noted within training blocks 1 to 6 and 1 to 7, respectively (P < .05). MOT-ST and fastest trial score success speed demonstrated excellent test-retest reliability between blocks 8 and 9. There was no effect of detraining period on performance during retraining. CONCLUSIONS: Eighteen tests are necessary to overcome training effects and establish a reliable baseline when MOT-ST is used as the performance outcome. Detraining periods up to 2 weeks did not impact performance. The average of 3 discrete tests should be used when assessing MOT-ST performance.

Supervised Offseason Training Programs are able to mitigate the Effects of Detraining in Youth Men Soccer Players Physical Fitness: A Randomized Parallel Controlled Study.

This study aimed to analyze the effects of three off-season training programs on the aerobic capacity, countermovement jump (CMJ), and linear sprint performance of young male soccer players. The study employed a randomized multi-arm design, consisting of three experimental groups: i) a high-intensity interval training (HIIT) group; (ii) a plyometric jump training (PJT) group; and (iii) a HIIT+PJT group; and an inactive control group. Fifty-eight under-19 male soccer players (aged 17.6 ±0.6 years) were randomly assigned to participate in a 3-week offseason training program exclusively performing HIIT, PJT, or a combination of both, while the fourth group remained inactive. Players underwent assessments twice, using the Yo-Yo Intermittent Recovery Test - Level 1 (YYIRT), CMJ, and 30-meter linear sprint. Significant interactions between time and groups were found in CMJ (p<0.001), YYIRT (p<0.001), and 30-m sprint (p<0.001). Group*time interaction revealed that the control group was significantly different from HIIT (p<0.001), PJT (p<0.001), and HIIT+PJT (p<0.001) considering the CMJ. Moreover, the control group was significantly different from HIIT (p=0.037) in YYIRT. Finally, the control group was significantly different from HIIT (p=0.024), PJT (p<0.001), and HIIT+PJT (p=0.021) considering the 30-m sprint. In conclusion, off-season training programs are effective in significantly reducing declines in CMJ and sprint performance compared to maintaining training cessation. However, in the YYIRT, only HIIT seems to be significantly superior to maintaining inactivity. To mitigate aerobic performance declines, incorporating HIIT sessions twice weekly during the offseason is advisable. To enhance or maintain jump performance, integrating at least one session of PJT weekly is beneficial.

Branched-chain amino acid supplementation suppresses the detraining-induced reduction of mitochondrial content in mouse skeletal muscle.

Exercise training enhances oxidative capacity whereas detraining reduces mitochondrial content in skeletal muscle. The strategy to suppress the detraining-induced reduction of mitochondrial content has not been fully elucidated. As previous studies reported that branched-chain amino acid (BCAA) ingestion increased mitochondrial content in skeletal muscle, we evaluated whether BCAA supplementation could suppress the detraining-induced reduction of mitochondrial content. Six-week-old male Institute of Cancer Research (ICR) mice were randomly divided into four groups as follows: control (Con), endurance training (Tr), detraining (DeTr), and detraining with BCAA supplementation (DeTr + BCAA). Mice in Tr, DeTr, and DeTr + BCAA performed treadmill running exercises [20-30 m/min, 60 min, 5 times/week, 4 weeks]. Then, mice in DeTr and DeTr + BCAA were administered with water or BCAA [0.6 mg/g of body weight, twice daily] for 2 weeks of detraining. In whole skeletal muscle, mitochondrial enzyme activities and protein content were decreased after 2 weeks of detraining, but the reduction was suppressed by BCAA supplementation. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein content, a master regulator of mitochondrial biogenesis, was decreased by detraining irrespective of BCAA ingestion. Regarding mitochondrial degradation, BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), a mitophagy-related protein, was significantly higher in the Tr group than in the DeTr + BCAA group, but not different from in the DeTr group. With respect to mitochondrial quality, BCAA ingestion did not affect oxygen consumption rate (OCR) and reactive oxygen species (ROS) production in isolated mitochondria. Our findings suggest that BCAA ingestion suppresses the detraining-induced reduction of mitochondrial content partly through inhibiting mitophagy.

Long-term detraining reverses the improvement of lifelong exercise on skeletal muscle ferroptosis and inflammation in aging rats: fiber-type dependence of the Keap1/Nrf2 pathway.

We investigated the effects of lifelong aerobic exercise and 8 months of detraining after 10 months of aerobic training on circulation, skeletal muscle oxidative stress, and inflammation in aging rats. Sprague-Dawley rats were randomly assigned to the control (CON), detraining (DET), and lifelong aerobic training (LAT) groups. The DET and LAT groups began aerobic treadmill exercise at the age of 8 months and stopped training at the 18th and 26th month, respectively; all rats were sacrificed when aged 26 months. Compared with CON, LAT remarkably decreased serum and aged skeletal muscle 4-hydroxynonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. Superoxide dismutase 2(SOD2) levels were higher in the LAT group than in the CON group in skeletal muscle. However, DET remarkably decreased SOD2 protein expression and content in the skeletal muscle and increased malondialdehyde (MDA) level compared with LAT. Compared with LAT, DET remarkably downregulated adiponectin and upregulated tumor necrosis factor alpha (TNF-α) expression, while phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and 70-kDa ribosomal protein S6 kinase (P70S6K) protein expression decreased, and that of FoxO1 and muscle atrophy F-box (MAFbX) proteins increased in the quadriceps femoris. Adiponectin and TNF-α expression in the soleus muscle did not change between groups, whereas that of AKT, mammalian target of rapamycin (mTOR), and P70S6K was lower in the soleus in the DET group than in that in the LAT group. Compared with that in the LAT group, sestrin1 (SES1) and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression in the DET group was lower, whereas Keap1 mRNA expression was remarkably upregulated in the quadriceps femoris. Interestingly, the protein and mRNA levels of SES1, Nrf2, and Keap1 in soleus muscle did not differ between groups. LAT remarkably upregulated ferritin heavy polypeptide 1(FTH), glutathione peroxidase 4(GPX4), and solute carrier family 7member 11 (SLC7A11) protein expression in the quadriceps femoris and soleus muscles, compared with CON. However, compared with LAT, DET downregulated FTH, GPX4, and SLC7A11 protein expression in the quadriceps femoris and soleus muscles. Long-term detraining during the aging phase reverses the improvement effect of lifelong exercise on oxidative stress, inflammation, ferroptosis, and muscle atrophy in aging skeletal muscle. The quadriceps femoris is more evident than the soleus, which may be related to the different changes in the Keap1/Nrf2 pathway in different skeletal muscles.

Residual effects of 12 weeks of power-oriented resistance training plus high-intensity interval training on muscle dysfunction, systemic oxidative damage, and antioxidant capacity after 10 months of training cessation in older people with COPD.

OBJECTIVE: This study aimed to assess the residual effects of a 12-week concurrent training program (power training + high-intensity interval training) in older adults with chronic obstructive pulmonary disease (COPD). METHODS: A total of 21 older adults with COPD [intervention (INT), n = 8; control (CON), n = 13; 76.9 ± 6.8 years] were assessed at baseline and 10 months after the completion of the intervention by the short physical performance battery (SPPB), health-related quality of life (EQ-5D-5L), vastus lateralis muscle thickness (MT), peak pulmonary oxygen uptake (peak VO2 ) and peak work rate (Wpeak ), early and late isometric rate of force development (RFD), leg and chest press maximum muscle power (LPmax and CPmax ), and systemic oxidative damage and antioxidant capacity. RESULTS: Compared to baseline, after 10 months of detraining, the INT group presented increased SPPB (∆ = 1.0 point), health-related quality of life (∆ = 0.07 points), early RFD (∆ = 834 N∙s-1 ), LPmax (∆ = 62.2 W), and CPmax (∆ = 16.0 W) (all p < 0.05). In addition, a positive effect was noted in INT compared to CON regarding MT and Wpeak (both p < 0.05). No between-group differences were reported in peak VO2 , late RFD, systemic oxidative damage, and antioxidant capacity from baseline to 10 months after the completion of the intervention (all p > 0.05). CONCLUSIONS: Twelve weeks of concurrent training were enough to ensure improved physical function, health-related quality of life, early RFD and maximum muscle power and to preserve MT and Wpeak but not peak VO2 , late RFD, systemic oxidative damage and antioxidant capacity in the subsequent 10 months of detraining in older adults with COPD.

Aerobic capacity and [Formula: see text] kinetics adaptive responses to short-term high-intensity interval training and detraining in untrained females.

PURPOSE: This study investigated the physical fitness and oxygen uptake kinetics (τ[Formula: see text]) along with the O2 delivery and utilization (heart rate kinetics, τHR; deoxyhemoglobin/[Formula: see text] ratio, ∆[HHb]/[Formula: see text]) adaptations of untrained female participants responding to 4 weeks of high-intensity interval training (HIIT) and 2 weeks of detraining. METHODS: Participants were randomly assigned to HIIT (n = 11, 4 × 4 protocol) or nonexercising control (n = 9) groups. Exercising group engaged 4 weeks of treadmill HIIT followed by 2 weeks of detraining while maintaining daily activity level. Ramp-incremental (RI) tests and step-transitions to moderate-intensity exercise were performed. Aerobic capacity and performance (maximal oxygen uptake, [Formula: see text]; gas-exchange threshold, GET; power output, PO), body composition (skeletal muscle mass, SMM; body fat percentage, BF%), muscle oxygenation status (∆[HHb]), [Formula: see text], and HR kinetics were assessed. RESULTS: HIIT elicited improvements in aerobic capacity ([Formula: see text], + 0.17 ± 0.04 L/min; GET, + 0.18 ± 0.05 L/min, P < 0.01; PO-[Formula: see text], ± 23.36 ± 8.37 W; PO-GET, + 17.18 ± 3.07 W, P < 0.05), body composition (SMM, + 0.92 ± 0.17 kg; BF%, - 3.08% ± 0.58%, P < 0.001), and speed up the τ[Formula: see text] (- 8.04 ± 1.57 s, P < 0.001) significantly, extending to better ∆[HHb]/[Formula: see text] ratio (1.18 ± 0.08 to 1.05 ± 0.14). After a period of detraining, the adaptation in body composition and aerobic capacity, as well as the accelerated τ[Formula: see text] were maintained in the HIIT group, but the PO-[Formula: see text] and PO-GET declined below the post-training level (P < 0.05), whereas no changes were reported in controls (P > 0.05). Four weeks of HIIT induced widespread physiological adaptations in females, and the majority of improvements were preserved after 2 weeks of detraining except for power output corresponding to [Formula: see text] and GET.

Effects of an 11-Week Detraining, Imposed by the COVID-19 Confinement, on Handball Players' Shoulder Rotator Isokinetic Profile, Shoulder Range of Motion, and Ball Release Velocity.

Background and Objectives: The COVID-19 confinement significantly impacted the physical condition of athletes. However, the detraining impacts of this period on the shoulder rotator and range of motion in handball players have not been studied. Thus, the main aim of this study was to investigate the effect of this 11-week detraining period, imposed by the COVID-19 pandemic confinement, on the shoulder rotator isokinetic profile (peak torque, ratio, fatigue index), shoulder rotator and flexion range of motion, and ball release velocity in handball players. Materials and Methods: A total of 16 handball players, with a mean age of 22.38 (5.28) years, participated in this study. The isokinetic strength was assessed using two protocols (three repetitions at an angular velocity of 60°/s and 20 repetitions at an angular velocity of 180°/s). In addition, the range of motion and ball release (at jump and standing shots) were measured. All these measurements were assessed before and after the COVID-19 confinement. Results: The results showed a significant reduction in the peak torque of the external rotation of their dominant and non-dominant shoulders. In addition, confinement significantly increased the fatigue index of external rotation and internal rotation and reduced the range of motion of internal rotation. Additionally, the ball release velocity during standing and jump shots was significantly reduced. Conclusions: These results suggested that strengthening external and internal rotation as well as recovering the internal rotation range of motion may be necessary after a detraining period in order to prevent shoulder injuries.

Alterations in mitochondrial biogenesis and respiratory activity, inflammation of the senescence-associated secretory phenotype, and lipolysis in the perirenal fat and liver of rats following lifelong exercise and detraining.

The primary aims of this study were to determine the effects of lifelong exercise and detraining on age-related alterations in mitochondrial function, inflammation associated with senescence-associated secretory phenotype (SASP), and lipolysis in the perirenal fat and liver of rats. Female Sprague-Dawley rats were randomly assigned to four groups: young control (n = 12), old control (n = 12), detraining (n = 12), and lifelong exercise (n = 12). We then investigated mitochondrial function, SASP-associated inflammation, and lipolysis in the perirenal fat and liver using qRT-PCR and western blotting to assess the expression of AKT, hypoxia-inducible factor 1α (HIF-1α), nuclear factor-kappa B (NF-κB), c-jun kinase (JNK), and p38 mitogen-activated protein kinase (p38MAPK). In the tissues of both the perirenal fat and liver, lifelong exercise significantly improved mitochondrial function, SASP-associated inflammation, and lipolysis. Meanwhile, pathways associated with inflammatory regulation were inhibited, predominantly via the activation of phosphorylated-AKT (p-AKT) and suppression of HIF-1α in both tissues, and via JNK in the perirenal fat and p38MAPK in the liver. Furthermore, detraining activated NF-κB expression in both tissues and induced the upregulation of serum high-sensitivity C-reactive protein (hsCRP) levels. Collectively, lifelong exercise was found to exert beneficial effects by ameliorating age-related alterations in mitochondrial function, SASP-associated inflammation, and lipolysis in perirenal fat and liver tissues, potentially inhibiting inflammation via the JNK and p38 MAPK pathways, respectively, as well as the HIF-1α and AKT pathways in both tissues. In contrast, detraining induced high levels of circulating hsCRP by activating the NF-κB signaling pathway in both tissues.

The effect of the inclusion of trunk-strengthening exercises to a multimodal exercise program on physical activity levels and psychological functioning in older adults: secondary data analysis of a randomized controlled trial.

BACKGROUND: Engaging in multimodal exercise program helps mitigate age-related decrements by improving muscle size, muscle strength, balance, and physical function. The addition of trunk-strengthening within the exercise program has been shown to significantly improve physical functioning outcomes. Whether these improvements result in improved psychological outcomes associated with increased physical activity levels requires further investigation. We sought to explore whether the inclusion of trunk-strengthening exercises to a multimodal exercise program improves objectively measured physical activity levels and self-reported psychological functioning in older adults. METHOD: We conducted a secondary analysis within a single-blinded parallel-group randomized controlled trial. Sixty-four healthy older (≥ 60 years) adults were randomly allocated to a 12-week walking and balance exercise program with (n = 32) or without (n = 32) inclusion of trunk strengthening exercises. Each program involved 12 weeks of exercise training, followed by a 6-week walking-only program (identified as detraining). Primary outcome measures for this secondary analysis were physical activity (accelerometry), perceived fear-of-falling, and symptoms of anxiety and depression. RESULTS: Following the 12-week exercise program, no significant between-group differences were observed for physical activity, sedentary behaviour, fear-of-falling, or symptoms of anxiety or depression. Significant within-group improvements (adjusted mean difference [95%CI]; percentage) were observed in moderate-intensity physical activity (6.29 [1.58, 11.00] min/day; + 26.3%) and total number of steps per min/day (0.81 [0.29 to 1.33] numbers or + 16.3%) in trunk-strengthening exercise group by week 12. With respect to within-group changes, participants in the walking-balance exercise group increased their moderate-to-vigorous physical activity (MVPA) (4.81 [0.06 to 9.56] min/day; + 23.5%) and reported reduction in symptoms of depression (-0.26 [-0.49 to -0.04] points or -49%) after 12 weeks of the exercise program. The exercise-induced increases in physical activity levels in the trunk-strengthening exercise group were abolished 6-weeks post-program completion. While improvements in physical activity levels were sustained in the walking-balance exercise group after detraining phase (walking only). CONCLUSIONS: The inclusion of trunk strengthening to a walking-balance exercise program did not lead to statistically significant between-group improvements in physical activity levels or psychological outcomes in this cohort following completion of the 12-week exercise program. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12613001176752), registered on 28/10/2013.

Effects of High-Intensity Interval Training on the Vascular and Autonomic Components of the Baroreflex at Rest in Adolescents.

PURPOSE: In a sample of healthy adolescents, the authors aimed to investigate the effects of high-intensity interval exercise (HIIE) training and detraining on baroreflex sensitivity (BRS) and it's vascular and autonomic components at rest. METHODS: Nineteen volunteers were randomly allocated to (1) 4 weeks HIIE training performed 3 times per week or (2) a control condition with no intervention for the same duration as HIIE training. PRE, POST, and following 2 weeks of detraining resting supine heart rate and blood pressure were measured, and a cross-spectral method (integrated gain [gain in low frequency]) was used to determine BRS gain. Arterial compliance (AC) was assessed as the BRS vascular component. LFgain divided by AC (LFgain/AC) was used as the autonomic determinant of BRS. RESULTS: The HIIE training was completed with 100% compliance. HIIE did not change resting gain in low frequency (LFgain) (P = .66; effect size = 0.21), AC (P = .44; effect size = 0.36), or LFgain/AC (P = .68; effect size = 0.19) compared to control. CONCLUSION: Four weeks of HIIE training does not change BRS and its autonomic and vascular determinant in a sample of healthy adolescents at rest.

Did the quarantine period of covid-19 interfere with the physical demands of central referees and assistants in professional soccer in a high level competition in Brazil?

Objective: This study compares the performance demanded from central referees and soccer assistants during professional games before and after the quarantine of COVID-19 during the same competition. Equipment and methods: Ten central referees and 19 assistants were monitored. Using a watch with Global Positioning System technology and a heart rate monitor, data were obtained of the distance they moved and information on their heart rate. A game before the quarantine period was compared to a game played 128 days after the quarantine period. These participants represented all the referees who played at least one game in the pre- and post-quarantine period of the same high-level competition in Brazil. Results: The results indicated that the total distance, average, and maximum heart rate did not present significant differences between the pre-and post-quarantine time of the central and assistant referees, except for the distance covered by the assistant referees in the second half, which was significantly greater in the post-quarantine period (Δ% = 6.27; P = 0.034). In conclusion, the central referees and assistants' performance was not affected after the 128-day quarantine period compared to the traditional transition period between the 37-day seasons.

Objectif: Cette étude compare les performances exigées des arbitres centraux et des assistants de football lors de matchs professionnels avant et après la mise en quarantaine pour COVID-19 lors de la même compétition. Matériel et méthodes: Dix arbitres centraux et 19 assistants ont été suivis. À l'aide d'une montre dotée de la technologie Global Positioning System et d'un moniteur de fréquence cardiaque, des données ont été obtenues sur la distance parcourue et des informations sur leur fréquence cardiaque. Un jeu avant la période de quarantaine a été comparé à un jeu joué 128 jours après la période de quarantaine. Ces participants représentaient tous les arbitres qui ont joué au moins un match dans la période pré et post-quarantaine de la même compétition de haut niveau au Brésil. Résultats: Les résultats ont indiqué que la distance totale, la fréquence cardiaque moyenne et maximale ne présentaient pas de différences significatives entre le temps avant et après la quarantaine des arbitres centraux et assistants, à l'exception de la distance parcourue par les arbitres assistants en seconde période, qui était significativement plus élevée dans la période post-quarantaine (Δ % = 6,27 ; p = 0,034). En conclusion, les performances des arbitres centraux et des assistants n'ont pas été affectées après la période de quarantaine de 128 jours, comparativement à la période de transition traditionnelle entre les saisons de 37 jours.

[Effects of the COVID-19 lockdown on physical performance parameters in professional football]. / Auswirkungen des COVID-19-Lockdowns auf physische Leistungsparameter im professionellen Fußball: Eine narrative Literaturübersicht.

Background: Governmental measures in 2020 to contain the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) brought training and competition in professional soccer to a temporary halt in many countries. As a result of the lockdown, training possibilities were mostly limited to nonspecific home-based training methods. It is unclear whether the lack of sport-specific stimuli led to a reduction in the physical performance of soccer players. Methods: For the narrative review, the PubMed, Google Scholar and BISp-Surf databases were selectively searched for studies examining the effects of the lockdown on physical performance parameters in adult professional soccer players. Results: In this review six prospective longitudinal studies were included. In all studies home-based training was performed during quarantine. Of the studies four compared the performance of the soccer players with data from previous seasons and two studies assessed the performance of players immediately before and after the lockdown period. Discussion: While general strength and endurance performances can be maintained through home-based substitute training programs, the studies indicated that the lack of football-specific stimuli could have an impact on the rapid power and speed performances of soccer players. Progressive loading control especially for speed training should be considered when returning to regular training in order to reduce the risk of injuries.

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.

Exercise temperature regulation following a 35-day horizontal bedrest.

NEW FINDINGS: What is the central question of this study? Does a 35-day horizontal bedrest impair thermoeffector responses during whole-body submaximal exercise performed in temperate conditions? What is the main finding and its importance? Cardiovascular and muscular deconditioning ensuing from prolonged recumbency seems to augment, at least to a degree, exercise-induced increase in body core temperature, most likely due to an impairment in non-evaporative heat loss. The response is a function of the absolute exercise intensity imposed. ABSTRACT: We examined the effects of a 35-day horizontal bedrest on thermoregulation during whole-body exercise. Fifteen healthy men were randomly assigned to either a bedrest (BR; n = 10) or a control (CON; n = 5) group. Prior to bedrest, both groups performed 40-min constant-load upright cycling at 30% of their peak workload (Wpeak ; PRE). One and 2 days after bedrest, the BR group performed, in a randomised counterbalanced order, two 40-min trials at 30% of (i) the pre-bedrest Wpeak (i.e., at a fixed absolute intensity; POST-A) and (ii) the post-bedrest Wpeak (i.e., at a fixed relative intensity; POST-R). The CON group conducted only the POST-A trial, at the same time intervals. During the trials, rectal (Trec ) and skin ( T¯sk ) temperatures, and the forehead sweating rate (SwR) were monitored. In the CON group, no differences were observed between the trials. Bedrest potentiated moderately the Trec elevation during the latter part of POST-A (∼0.10°C; P ≤ 0.05), but not of POST-R (∼0.04°C; P = 0.11). In both post-bedrest trials, T¯sk was attenuated by ∼1.5-2.0°C throughout (P < 0.01), whereas the forehead SwR was not modulated. Trec and T¯sk were similar in POST-A and POST-R, yet the forehead SwR was more dependent on the relative workload imposed (P = 0.04). The present findings therefore suggest that the cardiovascular and muscular deconditioning ensuing from a 35-day bedrest may aggravate the exercise-induced increase in body core temperature when working at a given absolute intensity, most likely due to an impairment in non-evaporative heat loss.

Positive effect of combined exercise on adipokines levels and pubertal signs in overweight and obese girls with central precocious puberty.

BACKGROUND: The prevalence of precocious puberty is increasing. Obesity has been demonstrated to be associated with changes in the adipokine profile and incidence of early puberty in girls. This study assessed the pubertal signs, the levels of adiponectin, resistin, and tumor necrosis factor-alpha (TNF-α) after 12 weeks of combined exercise and 4 weeks of detraining in overweight and obese girls with precocious puberty. METHODS: Thirty overweight and obese girls (aged 7-9) with precocious puberty, who had received Triptorelin, were randomly divided into two groups (15 exercise and 15 control). Initially, serum levels of adiponectin, resistin, TNF-α, luteinising hormone (LH), and follicle-stimulating hormone (FSH) and the signs of puberty progression (bone age, uterine length, and ovarian volume) were measured. The exercise group performed 60 min of combined (aerobic and resistance) exercise three times/week for 12 weeks. The control group did not receive any exercise. 48 h after the last training session and after 4 weeks of detraining, all research variables were measured (also in the control group). The statistical method used for data analysis was repeated measures ANOVA. RESULTS: In the exercise group, adiponectin significantly increased and resistin significantly decreased after 12 weeks. After 4 weeks of detraining, adiponectin significantly decreased, but resistin significantly increased. TNF-α levels did not change significantly during the study. There was no significant difference in all of the factors in the control group. Throughout the 16-week study period, the rate of puberty and LH significantly decreased in both exercise and control groups, but FSH, LH/FSH and ovarian volume significantly decreased in the exercise group alone (P<0.05). CONCLUSIONS: Combined exercise increased adiponectin and decreased resistin and the rate of puberty. However, after 4 weeks of detraining, these effects diminished but did not disappear. TRIAL REGISTRATION: IRCT, IRCT56471. Registered 25 may 2021 - Retrospectively registered, https://fa.irct.ir/user/profile.

HIIT is superior than MICT on cardiometabolic health during training and detraining.

PURPOSE: This study investigated the cardiometabolic health of overweight/obese untrained individuals in response to 8 weeks of HIIT and MICT using a field approach, and to 4 weeks of training cessation (TC). METHODS: Twenty-two subjects performed 8 weeks of moderate intensity continuous training (MICT-n = 11) or high-intensity interval training (HIIT-n = 11) (outdoor running), followed by 4 weeks of TC. Cardiorespiratory fitness, body composition, arterial blood pressure, glucose metabolism and blood lipids were measured pre-training (PRE), post-training (POST) and TC. RESULTS: HIIT improved eight indicators of cardiometabolic health ([Formula: see text], BMI, body fat, visceral fat, systolic blood pressure, total cholesterol, fasting glucose and triglycerides-p < 0.05) while MICT only three ([Formula: see text], BMI, and visceral fat-p < 0.05). After 4 weeks of TC, four positive adaptations from HIIT were negatively affected ( [Formula: see text], visceral fat, systolic blood pressure and total cholesterol-p < 0.05) and three in the MICT group ([Formula: see text], BMI and visceral fat, p < 0.05). CONCLUSION: Eight weeks of HIIT performed in a real-world setting promoted a greater number of positive adaptations in cardiometabolic health of individuals with overweight/obese compared to MICT. Most of the positive effects of the HIIT protocol were also found to be longer lasting and maintained after the suspension of high-intensity interval running for 4 weeks. Conversely, all positive effects of MICT protocols were reversed after TC.