We performed a systematic review and meta-analysis to determine if hypoxic conditioning, compared to similar training near sea level, maximizes body mass loss and further improves cardiometabolic ...markers in overweight and obese individuals. A systematic search of PubMed, Web of Science and the Cochrane Library databases (up to January 2019) was performed. This analysis included randomized controlled trials with humans with overweight or obesity assessing the effects of HC on body mass loss or cardiometabolic markers. A subgroup analysis was performed to examine if HC effects differed between individuals with overweight or obesity. 13 articles (336 participants) qualified for inclusion. HC significantly decreased body mass (p = .01), fat mass (p = .04), waist/hip ratio (p < .001), waist (p < .001), LDL (p = .01), diastolic (p < .01) and systolic blood pressure (p < .01) with these effects not being larger than equivalent normoxic interventions. There were trends towards higher triglycerides decrement (p = .06) and higher muscle mass gain in hypoxic (p = .08) compared with normoxic condition. Also, the two BMI categories displayed no difference in the magnitude of the responses. Compared to normoxic equivalent, HC provides greater reductions in triglycerides and greater muscle growth, while body mass changes are similar. In addition, HC responses were essentially similar between individuals with overweight or obesity.
•HC significantly reduces body mass, fat mass, W/H ratio, waist circumference.•HC improves several cardiometabolic markers (triglycerides, LDL, HDL, SBP and DBP).•Only the magnitude of triglycerides decrease and muscle mass growth were greater in hypoxic than in normoxic condition.•HC effects were similar in individuals with overweight and obesity.
Ramos-Campo, DJ, Rubio-Arias, JÁ, Freitas, TT, Camacho, A, Jiménez-Diaz, JF, and Alcaraz, PE. Acute physiological and performance responses to high-intensity resistance circuit training in hypoxic ...and normoxic conditions. J Strength Cond Res 31(4): 1040-1047, 2017-The aim of this study was to analyze physical performance and physiological variables during high-intensity resistance circuit training (HRC) with the addition of 2 levels (moderate and high) of systemic hypoxia. Twelve resistance-trained young male subjects participated in the study. After a 6 repetition maximum testing session, participants performed 3 randomized trials of HRC: normoxia (NORM: fraction of inspired oxygen FiO2 = 0.21; ∼0 m altitude), moderate hypoxia (MH: FiO2 = 0.16; ∼2.100 m altitude), or high hypoxia (HH: FiO2 = 0.13; ∼3.800 m altitude), as controlled by a hypoxic generator. Bench press force, heart rate and heart rate variability, rating of perceived exertion, resting metabolic rate, energy cost, and countermovement jump were assessed in each session. Heart rate variability in HH was significantly lower (standard deviation of all normal NN intervals intervals between two "normal" beats = 111.9 vs. 86.7 milliseconds; standard deviation of the difference between consecutive NN intervals = 19.5 vs. 17.0 milliseconds; p ≤ 0.05) in comparison with NORM. There were significant differences in rating of perceived exertion between NORM and HH (11.6 vs. 13.8 points). Peak and mean force on the bench press were significantly lower (p ≤ 0.05) in HH when compared with MH (peak: 725 vs. 488 N; mean: 574 vs. 373 N). Energy cost was significantly higher (p ≤ 0.01) in both hypoxic conditions compared with NORM (NORM: 10.4; MH: 11.7; HH: 13.3 kJ·min). There were no differences between conditions in heart rate and countermovement jump variables. These results indicate that hypoxic stimuli during HRC exercise alter physical performance and physiological variables and affect how strenuous the exercise is perceived to be. High-intensity resistance circuit training in hypoxia increases the stress on the performance and physiological responses, and these differences must be taken into account to avoid an excessive overload.
Lateral wedge insoles and their use in ankle instability Palomo‐Fernández, Inés; Martín‐Casado, Laura; Marcos‐Tejedor, Félix ...
Scandinavian journal of medicine & science in sports,
September 2023, 2023-Sep, 2023-09-00, 20230901, Letnik:
33, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The aim of the present study is to assess the immediate effects of applying lateral wedge insoles of different heights (0.00, 0.3, 0.4, and 0.6 cm) in patients with chronic ankle instability (CAI) in ...normal and supinated feet during a Star Excursion Balance Test (SEBT) and in the reflex response of Peroneus Longus (PL), Peroneus Brevis (PB), and Tibialis Anterior (TA) over a 30° inversion of the feet. The effects of the height of the wedges were assessed using a double‐blind, crossover design. In total, 25 participants were allocated into two groups, depending on the foot posture (Normal = 12, Supinated = 13) and performed the tests in a random fashion. Reaction time (RT) of stabilizing muscles of the ankle was measured using superficial electromyography (EMG) and postural balance with the SEBT. Foot posture did not show any significant effects on the analyzed variables. Nonetheless, the use of a 0.3 cm external rearfoot wedge (PB p = 0.002; PL p = 0.066 and TA p = 0.006) and 0.6 cm (PB p = 0.043; PL p = 0.058 and TA p = 0.071) reduces RT in stabilizing muscles of the ankle and improves results in SEBT, except for the anterolateral direction, in subjects with CAI. Therefore, our results suggest that the use of lateral wedge insoles could reduce RT and improve dynamic balance in chronic ankle instability.
The literature suggests that high-intensity interval training (HIIT) is more effective than moderate-intensity continuous training (MICT) to improve functional ability. However, there is no evidence ...on including HIIT in a circuit programme (HIICT). Our objective was to determine what type of training (HIICT or MICT) induces greater adaptations in the functional ability and body mass index of middle-aged and older women. The study used a quasi-experimental randomized controlled trial with 54 participants (age = 67.8 ± 6.2 years). Participants were randomly allocated to HIICT (
= 18), MICT (
= 18) or a non-exercise control group (CG;
= 18). The participants in the HIICT or MICT groups trained twice a week (1 h/session) for 18 weeks. Forty-one subjects were analysed (HIICT;
= 17, MICT;
= 12, CG;
= 12). Five subjects presented adverse events during the study. Strength, gait, cardiorespiratory fitness, balance and body mass index were measured. A significant training x group interaction was found in the arm curl test, where HIICT was statistically better than MICT and CG. Likewise, HIICT was statistically better than the CG in the BMI interaction. In lower limb strength, gait/dynamic balance and cardiorespiratory fitness, both HIICT and MICT were statistically better than the CG. In conclusion, HIICT generated better adaptations in upper limb strength than MICT. Likewise, HIICT generated better adaptations in body mass index than CG. Finally, both HIICT and MICT had a similar influence on strength, cardiorespiratory fitness and gait/dynamic balance.
The aims of this study were 1) to describe the effects of a 54 km and 111 km ultra-endurance mountain race on the biomarkers of muscle damage and inflammation, 2) to compare the effects between the ...two races regarding the biomarkers of muscle damage and inflammation.
Sixteen ultra-endurance amateur runners volunteered to participate in this study. Ten runners completed a 54 km race (Group 1; age: 27.0 ± 5.7; height: 179.5 ± 5.8 cm; and body mass: 77.3 ± 10.7 kg) and six completed a 111 km race (Group 2; age: 30.5 ± 8.0; height: 179.4 ± 5.5 cm; and body mass: 76.2 ± 9.4 kg). Blood samples were taken at five different points during the investigation, 24 h before the race, immediately post-race, and again at 24, 48, and 72 h after the race.
There were increases in leukocyte (Group 1: p ≤ .001, ES = 2.8; Group 2: p = .001, ES = 3.5) and platelet concentrations (Group 1: p ≤ .001, ES = 2.3; Group 2: p = .02, ES = 1.7) post-races. Significant inter-race differences were also observed in leukocyte at 72 h (Group 1: 5.5 ± 0.9, Group 2: 4.2 ± 0.9, p = .012, ES = 1.5). Erythrocytes, hematocrit and hemoglobin concentration decreased after 54 km and 111 km races at 24, 48 and 72 h (p ≤.001, ES = 2.0–3.18). Serum uric acid concentration increased after the 54 km race (pre = 4.9 ± 1.2 – post = 7.3 ± 1.0 8 mg/dl; p ≤ .001, ES = 2.4), and also the 111 km race (pre = 5.3 ± 0.9 – post = 6.7 ± 0.8 mg/dl; p < .008, ES = 2.2). GPT, GOT and LDH had changed by the end of the races (p < .05) and differences between the groups were observed in GOT post-race (p = .008, ES = 1.7) 24 h (p = .004, ES = 1.8), 48 h (p = .007, ES = 1.6), and 72 h (p = .02, ES = 1.4) and also in LDH at 24, 48, 72 h. Serum creatinine decreased post-race in Group 1 (pre = 1.1 ± 0.1 – post = 1.4 ± 0.2 mg/dl; p = .001, ES = 1.5) and Group 2 (pre = 1.2 ± 0.1, post = 1.5 ± 0.2; p = .002, ES = 3.3) along with CK and myoglobin. In addition, values did not return to baseline levels after 72 h in Group 2 for C-reactive protein, myoglobin, and CK. Differences between the races were also observed post-race in Troponin I (Group 1 = 0.06 ± 0.05, 111 km = 0.02 ± 0.01 μg/l, p = .047, ES = 1.1) and C-reactive protein post-race (Group 2 = 2.5 ± 1.6, 111 km = 18.2 ± 6.4 mg/l, p ≤ .001, ES = 4.4) at 24 and 48 h.
The athletes had increased concentrations of markers associated with damage, inflammation, muscle injury and cardiac damage after the races. Furthermore, athletes who completed the greater distance (111 km) had higher concentrations of the markers associated with muscle damage and muscle inflammation which remained changed for a period of 72 h. However, the participants of the ‘shorter race’ showed higher values associated with cardiac damage. Consequently, athletes who take part in these kinds of races should wait at least 72 h before training with high load.
A systematic review with meta-analysis was conducted to analyze the effect of carbohydrate (CHO) intake during exercise and some variables that could moderate this effect on endurance performance. We ...included 136 studies examining the effect of CHO ingestion during endurance exercise in the meta-analysis. The overall effect on performance showed a significant increase after CHO intake compared to the placebo/control groups. A larger effect of CHO consumption is observed in time to exhaustion than in time trials performance test. Moreover, the effectiveness of CHO supplementation was greater the longer the duration of the events. Also, there seems to be a higher effect of CHO intake in lower trained than in higher trained participants. In contrast, the magnitude of performance change of CHO intake is not affected by the dosage, ergometer used, the type of intake of the CHO ingestion and the type of CHO. In addition, a lower rate of perceived exertion and higher power and heart rate are significantly associated with the ingestion of CHO during endurance exercise. These results reinforce that acute CHO feeding is an effective strategy for improving endurance performance, especially, in less trained subjects participating in time to exhaustion tests of longer durations.
Nutritional strategies may have an effect on body composition and physical performance. Intermittent fasting (IF) is an eating pattern that cycles between periods of eating and fasting in specified ...time periods. Moreover, it is a common strategy among members of the athlete population that are looking for weight loss. However, this strategy may negatively affect physical performance, as compared to other weight loss strategies. The main purpose of this research was to use a cross-over design to study the effects of HIIT, with or without intermittent fasting, on muscular and anaerobic performance in 14 active women (27 ± 6 y). To assess performance, body composition (anthropometry), hand-grip strength, and counter-movement jump (CMJ) height was measured, and a 30 s Wingate test was completed assessed. HIIT + IF reduced fat mass (1 kg,
< 0.05, d = 1.1; 1.5%,
< 0.01, d = 1.0) and increased CMJ height (6.2 cm,
< 0.001, d = 1.8). In addition, the change in CMJ height in HIIT + IF was higher over HIIT (5.2 cm,
< 0.001, d = 1.9). In conclusion, intermittent fasting could be a nutritional strategy to decrease fat mass and increase jumping performance. However, longer duration programs would be necessary to determine whether other parameters of muscle performance could be positively affected by IF.
We performed a systematic review and meta-analysis to study all published clinical trial interventions, determined the magnitude of whole-body hypertrophy in humans (healthy males) and observed the ...individual responsibility of each variable in muscle growth after resistance training (RT). Searches were conducted in PubMed, Web of Science and the Cochrane Library from database inception until 10 May 2018 for original articles assessing the effects of RT on muscle size after interventions of more than 2 weeks of duration. Specifically, we obtain the variables fat-free mass (FMM), lean muscle mass (LMM) and skeletal muscle mass (SMM). The effects on outcomes were expressed as mean differences (MD) and a random-effects meta-analysis and meta-regressions determined covariates (age, weight, height, durations in weeks…) to explore the moderate effect related to the participants and characteristics of training. One hundred and eleven studies (158 groups, 1927 participants) reported on the effects of RT for muscle mass. RT significantly increased muscle mass (FFM+LMM+SMM; Δ1.53 kg; 95% CI 1.30, 1.76,
< 0.001; I
= 0%,
= 1.00). Considering the overall effects of the meta-regression, and taking into account the participants' characteristics, none of the studied covariates explained any effect on changes in muscle mass. Regarding the training characteristics, the only significant variable that explained the variance of the hypertrophy was the sets per workout, showing a significant negative interaction (MD; estimate: 1.85, 95% CI 1.45, 2.25,
< 0.001; moderator: -0.03 95% CI -0.05, -0.001
= 0.04). In conclusion, RT has a significant effect on the improvement of hypertrophy (~1.5 kg). The excessive sets per workout affects negatively the muscle mass gain.
Objectives
To analyze the effects of a fast‐velocity concentric resistance training (FVCRT) program on maximum strength of upper and lower limb, gait speed, walking endurance, fatigue, physical ...self‐perception, and catastrophizing pain in people with multiple sclerosis (MS).
Materials and Methods
Participants were randomized to either an experimental EG (n = 18) or a control CG (n = 12) group. The EG carried out 10‐weeks of lower limb FVCRT. The CG did not perform any intervention. The maximum isometric voluntary contraction (MVIC) during knee extension, hand‐grip strength, gait speed, walking endurance, fatigue, physical self‐perception, and catastrophizing pain were measured.
Results
Inter‐group differences after intervention were found on the right and left sides in MVIC (p = .032; ES = ‐0.7 and p = .009; ES = ‐0.9), and hand grip strength (p = .003; ES = ‐1.0 and p = .029; ES = ‐0.7). After FVCRT, there was in increase in MVIC (p < .001; ES = ‐1.7 and p < .001; ES = ‐1.3) and hand grip strength (p < .001; ES = ‐1.3 and p < .001; ES = ‐1.3) on both right and left sides, respectively. In addition, gait speed (p = .023; ES = 1.3), walking endurance (p < .001; ES = ‐1.0), symptomatic fatigue (p = .004; ES = 0.6), and catastrophizing pain (p < .001; ES = 1.0) improved in EG.
Conclusion
Lower limb FVCRT improved the upper and lower limb strength, walking, symptomatic fatigue, and catastrophizing pain in MS participants.
The purposes of this study were to determine the impact of 6 weeks of whole‐body vibration training (WBVT) on maximum voluntary plantar flexor strength, muscle activity via surface electromyography ...(EMG), and muscle architecture measured at rest and during maximal contraction at different ankle joint angles in young healthy adults. Using a single‐blind study design, 28 healthy men and women were randomly assigned to control (CG; N = 14, 7 women) or whole‐body vibration training (WBVG; N = 14, 7 women) groups. Vibration training (20‐25 minutes; standing with knees flexed) was performed 3 week−1 for 6 weeks (18 sessions). Maximum isometric plantar flexor torque, muscle activity (medial and lateral gastrocnemius EMG) and medial gastrocnemius fascicle angle and length at rest and maximum contraction were tested at four ankle joint angles (ranging 45° to −15°; 0° = anatomical) before and after training. Significant increases (24.7%‐37.5%) were observed in peak torque (N∙m∙kg−1;%) at −15°, 0°, 15° and 30° joint angles from pre‐ to post‐intervention in WBVG, which were different to CG (no change) and greater at longer muscle lengths. No between‐group differences were observed in changes in EMG amplitudes measured during contraction or muscle architecture parameters at rest or during contraction. Six weeks of WBVT in young, healthy adults increased isometric plantarflexion strength at multiple joint angles, without detectible changes in EMG, muscle architecture, or body composition. Therefore, WBVT can significantly improve maximum plantar flexor strength at multiple joint angles (muscle lengths) in young healthy men, although the mechanisms underpinning the changes are currently unclear.
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