Evaluation of Shake Weight Protocol in Senior Populations

The Shake Weight® (SW®) is designed to improve muscular fitness in a quick and inexpensive way. This study aimed to determine if the SW® was an effective tool at improving muscular fitness, body composition, and bone mineral density (BMD) in post-menopausal women. Participants were 17 healthy, post-menopausal women from aMidwestern University and divided into two training (SW® and HIT) interventions that lasted 10 weeks. HIT participants performed three sets of 8 repetitions at 80% of their estimated 1RM for the chest press, leg press, lat pulldown, and seated row. SW® participants performed the exercises prescribed by the SW® manufacturer. Changes in muscular strength were determined via handgrip dynamometry and muscular endurance was determined via a modified YMCA bench press test. Surface electromyography was used to determine changes in motor unit recruitment. Neither group showed significant improvements in handgrip strength, BMD, fat mass, and the SW® group showed no significant change in YMCA scores. The SW® group had a significant reduction in fat free mass after the intervention (p = .033). The HIT group showed significant improvements in YMCA bench press scores (p = .013) and all measures of muscular strength via 8RM (p \u3c .05) except for the chest press. The HIT group showed significant increases in motor unit activity for the anterior deltoid and bicep while shaking either the dumbbell or the SW®. Neither group improved on any EMG measurement. This study indicates that the SW® is ineffective at altering muscular fitness, BMD, or body composition in post-menopausal women

Determining the role of exercise-induced heat in resistance exercise conditioning

Introduction: Exercise is known to increase body temperature, but the temperature of exercising muscle is under-examined, particularly in resistance exercise. Muscle temperature is of interest because muscle heating per se can promote hypertrophy and protect against atrophy. The aims of this project were to: (i) characterise muscle temperature responses to typical resistance exercise training regimes, (ii) investigate the feasibility of preventing the muscle temperature rise, and (iii) determine the extent to which exercise-induced heat underpins adaptations from resistance training. The hypotheses were that: i) high repetition, short-rest exercise would be the most thermogenic exercise regimen, and (ii) resistance training with prevention of exercise-induced rises in muscle temperature from the active muscle would attenuate hypertrophic and strength adaptation, when compared to matched training with exercise-induced heat accumulation. Methods: Two studies were completed. In Study 1, five physically-active participants (two females) undertook three work-matched resistance exercise sessions in randomised order, on separate days. Unilateral bicep curls were used in sessions representing hypertrophy training (3x10 repetitions at 67% 1RM), strength-endurance training (3x20 repetitions at 34% 1RM), and strength training (6x4 repetitions at 84% 1RM). Thereafter, the feasibility of preventing muscle temperature rise during a strength session was assessed using arm immersion in 14°C water for 10 minutes preceding the first exercise set and between each remaining set. Study 2 was a preliminary study on the effects of muscle temperature on adaptations to resistance exercise. Five healthy non-resistance trained participants (three females) completed a 6-week bicep curl resistance training programme using a contralateral limb-control design. Eighteen strength training sessions (6x4 repetitions at ~80% 1RM) were completed with one arm randomised to train in a cool state (“cool”, as described above) and the other arm training with natural heat accumulation (“warm”). Results: Study 1: The three regimes increased biceps brachii temperature to a similar extent; 2.0±0.8°C for hypertrophy, 2.5±1.0°C for strength-endurance, and 2.2±0.5°C for strength training (baseline: 35.3±0.8°C; time: p<0.001; condition: p=0.489; interaction: p=0.609). The first third of the exercise session accounted for 46±18%, 62±13% and 60±9% of the total muscle temperature rise for hypertrophy, strength-endurance and strength regimes, respectively (condition: p=0.147). Almost half (44±23%) of the muscle temperature increase was still evident after 15-min recovery, with no effect of condition (condition: p=0.649). Resistance exercise with cooling prevented muscle temperature exceeding its baseline (35.7±0.9°C; post- exercise: 34.6±1.2°C; p=0.164). Study 2: Peak isometric torque increased in both arms, with no effect of condition (warm: 11±11%; cool 4±7%; time: p=0.033; condition: p=0.310). Bicep curl 1RM increased similarly for both conditions (warm: 25±11%; cool 26±11%; time: p<0.001; condition: p=0.891). Trivial changes were observed in arm composition. Cool training attenuated increases in peak twitch amplitude, when assessed in a normothermic state in temperate conditions (warm: 38±26%; cool 2±7%; time: p=0.011; condition: p=0.016). Conclusion: All three regimes of resistance exercise increased biceps brachii temperature substantially and for a prolonged period. Immersion cooling effectively prevented any such increase. Preventing exercise-induced elevation in muscle temperature did not attenuate functional or structural adaptations to strength training, thereby indicating that muscle temperature lacks a role or is redundant in strength adaptations, although this remains to be determined in a larger population

Validez y fiabilidad de test de campo para evaluar la condición física relacionada con la salud en adultos. Proyecto Adult- Fit

Physical fitness is considered a powerful health marker in different populations (i.e., preschool, childhood, adolescence, adults, and older adults). Epidemiological studies have demonstrated an inverse association between cardiorespiratory and muscular fitness, with morbidity and all-cause mortality. Consequently, physical fitness assessment is considered an important prevention and diagnosis tool. Physical fitness can be objectively and accurately measured through laboratory tests. However, due to their high cost, the necessity of sophisticated instruments, qualified technicians, and time constraints, their use is limited in population-based studies. Field-based physical fitness tests provide a reasonable alternative since they are easy to administer, involve minimal equipment, are low in cost, and a large number of participants can be evaluated in a relatively short period of time and simultaneously. Valid, reliable, feasible, safe, and responsiveness are characteristics that need to be assured for any measurement tool. Longitudinal studies have recently contributed to the existing health-related fitness batteries archiving those characteristics in children and adolescents (The ALPHA Study), and preschool children (The PREFIT Study). However, researchers, clinicians, and sport practitioners do not have enough information about which field-based physical fitness tests are more reliable, valid, and informative from the health point of view to be implemented in adults. Therefore, the general aim of this International Doctoral Thesis was: to propose a battery of field-based tests to assess physical fitness related to health in adults based on scientific evidence, valid (i.e. predictive validity and criterion-related validity) and reliable, depending on sex, age, and physical activity level: The ADULT-FIT project [Plan nacional I+D +i 2017-2020, (ref.: DEP2017-88043-R)]. Likewise, the specific aims were: (i) to comprehensively analyze the predictive validity of the existing motor fitness and flexibility tests in relation to several health outcomes in adults and older adults (study I); (ii) to comprehensively study the criterion-related validity of the existing field-based physical fitness tests used in adults aged 18-64 years (study II), and to identify studies evaluating the criterion-related validity of existing field-based methods and equations for body composition estimation used in adults aged 18-64 years (study III); (iii) to systematically review studies conducted to examine the reliability of field-based physical fitness tests used in adults aged 18-64 years (study IV); (iv) to analyze the criterion-related validity and the reliability of the 2-km walk test and the 20-m shuttle run test for evaluating cardiorespiratory fitness in the adult population, according to sex, age, and physical activity level (study V), and to analyze the criterion-related validity and reliability of the standing long jump test to assess the lower-body explosive muscular fitness in adults, according to sex, age, and physical activity level (study VI). The main results showed that there is strong evidence indicating that: (i) slower gait speed, impaired balance, and worse TUG performance are good indicators of health outcomes in both adults and older adults; and limited evidence about the predictive validity of flexibility tests exists (study I). (ii) To assess cardiorespiratory fitness, the 20-m shuttle run test (using Leger’s equation), 1.5-mile run/walk test, 12-min run/walk test, 6-min walk test, YMCA step test, and the 2-km walk test (using Oja’s equation) are valid; to assess muscular fitness, the handgrip test (using the TKK dynamometer), and the Biering–Sørensen test are valid; to assess flexibility, the sit-and-reach test (and its different versions), and that the toe-to-touch tests are not valid; limited evidence about the criterion-related validity of motor fitness exists (study II). (iii) The field-based methods, waist circumference, body adiposity index, and body mass index are valid indicators of body adiposity in adult population; classical equations, such as Durnin/Womersley equation, Jackson/Pollock equation, Jackson, Pollock and Ward equation, and estimation equations implying skinfolds, alone or combined with circumferences, are most valid to estimate total body fat mass or body fat percentage in adult population (study III). (iv) To assess cardiorespiratory fitness, the 20-m shuttle run test, the step tests and the 6-min walk test are reliable; to assess musculoskeletal fitness, the handgrip test (using a JAMAR dynamometer), back-leg test, Biering-Sørensen (and its modified versions), trunk flexion sustained, 5-reps sit-to-stand, bilateral side and prone bridge, the sit-and-reach (and its modified versions), and the toe-to-touch test are reliable; to assess motor fitness, the T-test (and its modified version) is reliable, and the single- leg stand test (and its modified versions) is not reliable (study IV). (v) The 2-km walk test (using) and the 20-m shuttle run test, as well as their corresponding Oja’s and Leger’s equations, are valid and reliable for estimating cardiorespiratory fitness in adults aged 18-64 years. However, the 20-m shuttle run test obtained slightly greater criterion-related validity and reliability, regardless of sex, age, and physical activity level (study V). (vi) The standing long jump test may be a valid tool to assess the adult population's lower-body explosive muscular fitness, independent of age, and physical activity levels. The standing long jump test may be used when controlling the possible learning effect to provide reliability (study VI). This International Doctoral Thesis provides evidence to propose a battery of field-based tests to assess physical fitness related to health in adults based on valid and reliable scientific evidence, depending on sex, age, and physical activity levels. Future methodological studies are still necessary to establish the validity and/or reliability of those field-based physical fitness tests identified in systematic reviews having insufficient or strong evidence that have not been developed in this International Doctoral Thesis, as well as the feasibility and safety of those field-based physical fitness test identified (in the systematic reviews) as valid and reliable, and the responsiveness of those field-based physical fitness test identified as valid, reliable, feasible and safe, in adult population

Long term adaptations and mechanisms of different protocols of ''concurernt'' training in recreationally trained male adults.

The combination of resistance and endurance solicitations within the same training program or session appears to be a compulsory path to achieving high performance in many sports. Those performances are highly dependent on multiple physical qualities that must be developed simultaneously, whereas having appropriate concurrent training allows for better neuromuscular adaptation. Thus, the identification of a single form of physical training that promotes broad physical fitness adaptations within less time would be of great benefit to physical training specialists. Therefore, the general objective was to evaluate and compare the neuromuscular, metabolic, cardiorespiratory, structural (body composition and muscle architecture), and mechanical long-term adaptations between the three different concurrent training methods; Traditional Concurrent Training (TCT), Sprint Interval Training (SIT), and High-intensity Resistance Circuit-based training (HRC) in young recreationally training athletes. In addition, the specific objectives were to identify the long-term neuromuscular, metabolic, cardiorespiratory, structural (body composition and muscle architecture), and mechanical adaptation and mechanism following three different concurrent training (HRC, SIT, and TCT) in the same sample. To achieve these objectives, the convenience sampling method was used for a single-blinded randomized controlled trial experimental research design to recruit thirty-four young recreationally training male athletes (24±5.8 years, 174.9±5.9 cm height, and 73.4±7.9 kg) and randomly assigned to three training groups (HRC: 13, SIT: 10, and TCT: 11). The study consisted of five total visits to the laboratory: Visit #1 – Initial assessment for requirement test and familiarization session, Visit #2 – pre-training evaluation, Visit #3 – continuation of pre-training evaluation, Visit #4 – post-training testing, and Visit #5 – continuation of post-training testing. The entire study has taken approximately ten weeks but all subjects exercised twice a week for 8 weeks during the intervention. During Visits # 2, 3, 4, and #5 neuromuscular, metabolic, cardiorespiratory, structural (body composition and muscle architecture), and mechanical variables were assessed. Standard descriptive statistics were used to characterize the study population. A mixed analysis of variance with repeated measures and the Bonferroni post hoc test were used to investigate the interaction effect and significant differences within and between groups. The findings of the study are explained through five sections and the main findings of section 01 showed each training procedure had a unique neuronal adaptation that was most particular to its training character. Whereas SIT and TCT protocols demonstrated spinal adaptation throughout the intervention, HRC demonstrated supraspinal and spinal adaptation. It follows that while theoretically all of these adaptations exhibit both quantitatively positive and negative changes, both changes are crucial to improving athletic performance. Furthermore, the main findings of section 02 revealed that although no training approach is superior to the others, following three distinct concurrent training regimens caused different metabolic improvements in blood lipid profiles. Particularly, the TCT protocol was an ideal training method to lower total cholesterol levels and increase HDL-C, but SIT protocol is a time-effective method for performance-based programs that induced a decrease in cholesterol, triglycerides, and LDL-C, whereas HRC also induced positive and negative alterations. Thus, each user could be able to select any training protocol following their needs. Moreover, section 03 exposed that the TCT protocol is much better than the other two concurrent training methods (HRC and SIT); in terms of enhancing the cardiorespiratory variables in recreationally trained individuals. However, following HRC and SIT also induced an increase in VO2 max and RMR, but the time consumed by the training sessions is lesser than TCT. Since HRC and SIT are very time efficient and contribute to enhancing cardiorespiratory adaptations, it would be advantageous to use a single mode of an exercise training protocol to improve cardiorespiratory variables. Hence, it is depending on the needs and desires of each individual in terms of their available time for exercising as well as the training plans. In addition, section 04 observed that HRC, SIT, and TCT offered different body composition and muscle architecture benefits after the 8 weeks training period but no single program was better than another, but the time spent on the training sessions differed. Hence, depending on the necessity of the subjects they can select the training method for their training schedule. Need to write about the body composition Interestingly, section 05 revealed that the HRC training program is better than other concurrent training protocols (SIT and TCT) for enhancing force and power in young recreational male athletes. Although HRC is recommended since it is so time-effective, the athlete's or coach's preferences may also call for the use of the other two training protocols throughout their training sessions. Finally, it revealed that all training protocols enhance more or less adaptation respective to each other but some training methods are very time efficient than other training protocols. Thus, depending on the necessity of each athlete and their coaches they can select the training protocol for their training schedule.Actividad Física y Deport

Examination of Sex- and Limb-Specific Fatigue During Unilateral, Isometric Forearm Exercise

The purpose of this study was to examine the effects of unilateral, isometric handgrip holds to failure for the dominant (Dm) and non-dominant (NDm) limb on ipsilateral ([IPS] exercised side) and contralateral ([CON] non-exercised side) performance fatigability. Twenty individuals participated in this study (Men [n =10]; Women [n = 10; Composite Demographics: Age: 22.2 years; Height: 174.4 cm; Body Mass: 75.0 kg) and completed three visits. Two, 6 s maximal voluntary isometric contractions (MVICs) for the Dm and NDm limb were performed during visit 1, followed by a familiarization of the fatigue test. Visits 2 and 3 included an isometric, handgrip hold to failure (HTF) fatigue test at 50% MVIC for either the Dm or NDm limb using a handgrip dynamometer (iWorx Systems Inc.; Dover, NH 03820). Prior to, and immediately after the HTF, a MVIC was performed on the IPS and CON sides. The fatigue test (Dm or NDm) was randomized between visits and the side tested first (IPS and CON) was randomized for pre-and post-tests, within and between each visit. The perceptual measures of Rating of Perceived Exertion (RPE) for the Active Muscle (AM) and Overall Body (O), along with the Numerical Pain Rating (NPR) for the AM and O were taken following each MVIC and the HTF. The test-retest reliability of the Dm and NDm hand pre-HTF MVIC demonstrated ‘excellent’ reliability (Dm: ICC = 0.936; NDm: ICC = 0.938) while the Dm limb HTF demonstrated ‘fair’ reliability (ICC = 0.553) with no systematic error for either the MVIC or HTF. Men and women demonstrated similar times for the HTF (Dm limb: 130.3 ± 36.8 s; NDm limb: 112.1 ± 34.3 s; p = 0.002), despite the men (46.07 ± 10.64 kg) demonstrating a significantly greater absolute MVIC force than women (30.52 ± 6.93 kg; p ≤ 0.001). Performance fatiguability (decrease in exercise performance) and facilitation (increase in exercise performance) was calculated a via a priori planned comparisons (%D = ((pre-HTV MVIC – post-HTF MVIC) / pre-HTV MVIC)*100)). Men, collapsed across limb, demonstrated IPS limb (%D = 22.9 ± 10.8%) performance fatiguability and CON limb facilitation (%D = -6.1 ± 6.9%) following the HTF, while women demonstrated differences in performance fatiguability between the Dm and NDm limbs in IPS (Dm: %D = 28.0 ± 9.4%; NDm: %D = 32.3% ± 10.1%; p = 0.027), but no significant changes in the CON limbs (Dm: %D = -1.6 ± 5.7%; NDm: %D = 1.7 ± 5.9%). Following the HTF, men (9.2 ± 1.1) demonstrated a greater RPE-AM value than women (7.4 ± 2.2; p = 0.031), but the RPE-O, NPR-AM, NPR-O demonstrated no differences. The perceptual responses for the Pre-/Post-HTF in men demonstrated increases in RPE-AM and RPE-O in both limbs; women demonstrated increases in the IPS side only. The NPR-AM and NPR-O measures demonstrated increases for the men in both limbs and the women in the IPS side only. In this study, women demonstrated less absolute grip strength than men and demonstrated greater Dm limb strength than NDm grip strength while the men demonstrated no difference between limbs. Sex-specific training programming and body composition differences may have influenced this finding as well as the finding that the RPE-AM for a 50% MVIC HTF was higher for the men than women despite similar times to failure. The Dm limb was more fatigue resistant than the NDm limb, possibly due to continual favoring of the Dm limb in everyday tasks. Similar performance fatiguability in the IPS limb was demonstrated for men and women, however, the men demonstrated facilitation in the CON limb while there were no CON limb changes for the women. The finding of facilitation may be due to central factors, such as interhemispheric excitatory signaling from the ipsilateral to the contralateral hemisphere, and peripheral factors such as post activation potentiation (PAP) elicited from myosin light chain phosphorylation. The PAP phenomenon occurs more frequently in type II muscle fibers. Thus, the sex-dependent differences seen in facilitation and perceptual responses may be related to a greater proportion of type II fibers for the men compared to the women

Acute Effects of Sprint Interval Training and Blood Flow Restriction on Neuromuscular and Muscle Function

The purpose of this investigation was to examine the effects of continuous (CBFR) and intermittent (IBFR) blood flow restriction (BFR) applied during sprint interval training (SIT) on performance, muscle, and neuromuscular function. Fifteen men completed SIT with CBFR, IBFR, and No-BFR. Each SIT bout consisted of 2, 30-s maximal sprints on a cycle ergometer with a resistance of 7.5% of body mass. Concentric peak torque (CPT), maximal voluntary isometric contraction (MVIC) torque, and muscle thickness (MT) were measured before and after the SIT protocols during each visit. During the maximal strength assessments, surface electromyography (sEMG) was recorded and during each SIT, peak and mean RPM were measured, and power output was examined relative to the sEMG-based physical working capacity at the fatigue threshold (PWCFT). CPT and MVIC torque decreased from pretest (220.3±47.6 Nm and 355.1±72.5 Nm) to posttest (147.9±27.7 Nm and 252.2±45.5 Nm), while MT increased (1.77±0.31 cm to 1.96±0.30 cm). There were no changes in sEMG amplitude assessed during the CPT (+6.5±22.5%) and MVIC (+7.7±24.1%) muscle actions, while sEMG mean power frequency decreased during the CPT (-12.8±10.5%) and MVIC (-8.7±10.2%) muscle actions. Collapsed across Sprint, %PWCFT was greater during No-BFR (414.2±121.9%) than CBFR (375.9±121.9%). Peak and mean RPM decreased from Sprint 1 to Sprint 2 for No-BFR (157.7±12.5 and 110.4±7.1 RPM to 147.5±12.8 and 85.5±9.9 RPM), CBFR (153.9±14.5 and 105.2±11.5 RPM to 129.2±13.5 and 73.6±14.0 RPM) and IBFR (158.0±14.4 and 110.3±8.6 RPM to 134.1±15.7 and 81.2±12.5 RPM). During Sprint 1, mean RPM was greater for No-BFR than CBFR, while during Sprint 2, both No-BFR and IBFR were greater than CBFR. Collectively, the findings of the present study indicated that SIT with or without BFR did not affect neuromuscular function and induced comparable reductions in neuromuscular fatigue and sprint performance across all conditions