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The Influence of a Personal Fitness Trainer on Self-Selected Resistance Training Intensity in Healthy Women: 1799
Abstract
The purpose of the present investigation was to examine the influence of resistance training with a personal trainer versus unsupervised resistance training on the self-selected intensities used by women during resistance exercise. Forty-six resistance-trained women (age = 26.6 6 6.4 years; body mass = 64.2 6 10.9 kg) who either trained individually (n = 27; No PT) or with a personal trainer (n = 19; PT) were carefully instructed to select a weight they used in their own resistance training workouts that enabled the completion of 10 repetitions for the chest press (CP), leg press (LP), seated row (SR), and leg extension (LE) exercises. Each participant was subsequently tested for one repetition-maximum (1RM) strength on each exercise, and the self-selected intensity was calculated based on a percent of each 1RM value. For self-selected relative intensity, the PT group selected significantly greater intensities for LP (50% vs. 41%), CP (57.4% vs. 48%), and SR (56% vs. 42%) whereas a trend (p = 0.10) was observed for LE (43% vs. 38%) compared with No PT. Overall, the average self-selected intensity for all exercises was ~51.4% in PT group and ~42.3% in the No PT group. 1RM values for LP, LE, and SR were greater in the PT than No PT group. Ratings of perceived exertion values were significantly greater in the PT compared with the No PT group for CP, LE, and SR but not LP. These results indicate that resistance training under the supervision of a personal trainer leads to greater initial 1RM strength values, self-selection of greater workout intensities, and greater ratings of perceived exertion values during resistance exercise.
El objetivo es determinar los motivos, objetivos principales y secundarios de las mujeres que solicitan el servicio de un entrenador personal, y comprobar la fiabilidad y generalizabilidad de la estructura de datos. Participaron 70 mujeres con edades comprendidas entre los 24 y los 68 años. Se utilizó un cuestionario ad hoc con preguntas abiertas. Al cabo de dos años se tomaron los datos del tiempo que las practicantes habían permanecido de forma continua vinculadas al programa de entrenamiento personal, y también el porcentaje de asistencia a las sesiones de entrenamiento programadas. Se realizo un análisis de asociación usando el Chi-cuadrado, el coeficiente de contingencia y la correlación de Spearman (p
The aim is to determine the reasons, primary and secondary objectives of women who request the services of a personal trainer, and check the reliability and generalizability of the data structure. 70 women aged between 24 and 68 years participated. It was used an ad hoc questionnaire with open questions. After two years, it was taken the
data of the time that the users had remained continuously linked to the personal training program, and also the percentage of attendance at scheduled training sessions. It was carried out an association analysis using the Chi-square, the contingency coefficient and the Spearman´s correlation (p <.001), a variance component analysis (p <.001) and a generalizability analysis. The results indicate that the most requested primary objective was the weight loss
by reduction of the body fat percentage, the secondary objective was to improve muscle stiffness, and the primary reason was to get the results, however, these variables are associated with the user's age (p <.001). The data structure obtained with this sample shows excellent levels of reliability (e 2= 1.00) and generalizability (Φ = 1.00). In conclusion, the knowledge of the reasons and objectives of the users could be useful for the manager of sports centers, when manage the service to provide a quality service, with which to achieve the satisfaction and loyalty of the user.
Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the use of beta-hydroxy-beta-methylbutyrate (HMB) as a nutritional supplement. The ISSN has concluded the following. 1. HMB can be used to enhance recovery by attenuating exercise induced skeletal muscle damage in trained and untrained populations. 2. If consuming HMB, an athlete will benefit from consuming the supplement in close proximity to their workout. 3. HMB appears to be most effective when consumed for 2 weeks prior to an exercise bout. 4. Thirty-eight mg.kg.BM-1 daily of HMB has been demonstrated to enhance skeletal muscle hypertrophy, strength, and power in untrained and trained populations when the appropriate exercise prescription is utilized. 5. Currently, two forms of HMB have been used: Calcium HMB (HMB-Ca) and a free acid form of HMB (HMB-FA). HMB-FA may increase plasma absorption and retention of HMB to a greater extent than HMB-CA. However, research with HMB-FA is in its infancy, and there is not enough research to support whether one form is superior. 6. HMB has been demonstrated to increase LBM and functionality in elderly, sedentary populations. 7. HMB ingestion in conjunction with a structured exercise program may result in greater declines in fat mass (FM). 8. HMB's mechanisms of action include an inhibition and increase of proteolysis and protein synthesis, respectively. 9. Chronic consumption of HMB is safe in both young and old populations.
This study investigated the effects of a high volume 5-wk weight training program and different exercise/rest intervals on measures of power, high intensity exercise endurance (HIEE), and maximum strength. Subjects, 33 weight trained men (M age 20.4+/-3.5 yrs), were divided into 3 equal groups. The groups used the same exercises and set-and-repetition scheme. Rest intervals were 3 min for Gp 1, 1.5 min for Gp 2, and 0.5 min for Gp 3. Pre/post changes were analyzed using G x T ANOVA. Peak power, average peak power, and average total work, as measured during 15 five-sec cycle max-efforts rides and the 1-RM squat, increased significantly (N = 33, p < 0.05). The vertical jump and vertical jump power index did not show a statistically significant change. The 1-RM squat increased significantly more in Gp 1 (7%) than in Gp 3 (2%). Data suggest that, except for maximum strength, adaptations, to short-term, high-volume training may not be dependent on the length of rest intervals.
(C) 1995 National Strength and Conditioning Association
Traditional gender roles and differences in absolute strength have resulted in misconceived approaches to strength training for women. Male physiology, more than hormones, explains men's superior absolute strength. When other measures of strength are used, such as strength relative to cross-sectional area of muscle, the strength of men and women is nearly equal. Women who practice the same well-designed strength training programs as men benefit from bone and soft-tissue modeling, increased lean body mass, decreased fat, and enhanced self-confidence.
The ability to maximally generate active muscle tension during resistance training has been established to be a primary determinant for strength development. The influence of intrasession rest intervals may have a profound effect on strength gains subsequent to short-term high intensity training. The purpose of this study was to examine the effects of rest interval on strength and functional performance after four weeks of isokinetic training.
Fifteen healthy college aged individuals were randomly assigned to either a short rest interval group (group 1, n = 8) or a long rest interval group (group 2, n = 7). Subjects were evaluated for quadriceps and hamstring isokinetic strength at 60 (five repetitions) and 180 (30 repetitions) degrees/second and functional performance with the single leg hop for distance test. One leg of each subject was randomly assigned to a four week, three days/week isokinetic strength training programme for concentric knee extension and flexion performed at 90 degrees/second. Subjects in group 1 received a 40 second rest interval in between exercise sets, whereas subjects in group 2 received a 160 second rest period.
A two factor analysis of variance for the pre-test--post-test gain scores (%) showed significantly greater improvements for isokinetic hamstring total work and average power at 180 degrees/second for the trained limb of subjects in group 2 than their contralateral non-trained limb and the subjects in group 1. Significantly greater improvements for the single leg hop for distance were also found for the trained limbs of subjects in both groups as compared with the non-trained limbs.
The findings indicate that a relatively longer intrasession rest period resulted in a greater improvement in hamstring muscle strength during short term high intensity training.
The purpose of this study was to examine the effects of different rest interval (RI) lengths on metabolic responses to the bench press. Eight resistance-trained men performed 10 randomized protocols [five sets of bench press with 75 or 85% of 1RM for ten (10REP) and five repetitions (5REP), respectively, using different RI (30 s, 1, 2, 3, 5 min)]. Oxygen consumption (VO2) was measured during exercise and for 30 min post exercise. For 30-s and 1-min RI: reductions (15–55%) in resistance and volume were observed (set 5 < 4 < 3 < 2 < 1). For 2-min RI: performance was maintained during the first two sets but was reduced by 8–29% during sets 3–5. For 3-min RI: a reduction was observed in volume where sets 4 and 5 were lower than sets 1–3 (∼21%). For 5-min RI: only a reduction in set 5 was observed. Mean VO2 and ventilation (V
E) were progressively higher as RI length was shortened. VO2 area under the curve indicated 10REP > 5REP for all RI except 1-min. Respiratory exchange ratio (RER) was elevated similarly for each protocol. Post exercise, VO2, V
E, and RER were elevated through 30 min. No differences between RI were observed following 10REP; however, VO2 after 30-s was higher than 2-, 3-, and 5-min and 1-min was higher than 5-min during 5REP. Fatigue rate was correlated (r = 0.30–0.49) to all metabolic variables. A continuum of performance reductions and metabolic responses were observed. The largest reductions in performance occurred with very short RI (<1 min), and performance was maintained during the first 3–4 sets when 3- and 5-min RI were used.
Eleven male subjects (20-32 years) accustomed to strength training went through progressive, high-load strength training for 24 weeks with intensities ranging variably between 70 and 120% during each month. This training was also followed by a 12-week detraining period. An increase of 26.8% (P less than 0.001) in maximal isometric strength took place during the training. The increase in strength correlated (P less than 0.05) with significant (P less than 0.05-0.01) increases in the neural activation (IEMG) of the leg extensor muscles during the most intensive training months. During the lower-intensity training, maximum IEMG decreased (P less than 0.05). Enlargements of muscle-fibre areas, especially of fast-twitch type (P less than 0.001), took place during the first 12 weeks of training. No hypertrophic changes were noted during the latter half of training. After initial improvements (P less than 0.05) no changes or even slight worsening were noted in selected force-time parameters during later strength training. During detraining a great (P less than 0.01) decrease in maximal strength was correlated (P less than 0.05) with the decrease (P less than 0.05) in the maximum IEMGs of the leg extensors. This period resulted also in decreases (P less than 0.05) of the mean muscle-fibre areas of both fibre types. It was concluded that improvement in strength may be accounted for by neural factors during the course of very intensive strength training. Selective training-induced hypertrophy also contributed to strength development but muscle hypertrophy may have some limitations during long-lasting strength training, especially in highly trained subjects.
The effects of three resistance training programs on muscular strength and on absolute and relative muscular endurance were investigated. Forty-three male college students were randomly assigned to the training protocols. The high resistance-low repetition group (n = 15) performed three sets of 6–8 RM (repetition maximum) per session. The medium resistance-medium repetition subjects (n = 16) trained by doing two sets of 30–40 RM per session, while the low resistance-high repetition group (n = 12) used a single set of 100–150 RM. All subjects trained with the bench press exercise three times per week for nine weeks. Tests of strength (1-RM), absolute and relative endurance were administered before and after training. Statistical analyses revealed that the 20% improvement in maximum strength by the high resistance-low repetition group was greater than the 8 and 5% gains reported for the medium resistance-medium repetition and low resistance-high repetition groups, respectively. Relative to absolute endurance, however, the 41 percent and 39 percent improvements registered by the low resistance-high repetition and medium resistance-medium repetition groups, respectively, were not significantly greater than the 28% gain reported for the high resistance-low repetition group. Results for the relative endurance test revealed that the high resistance-low repetition group's performance actually decreased by 7% after training, and was significantly poorer than the 22% and 28% improvements made by the other two groups. It was concluded that human skeletal muscle makes both general and specific adaptations to a training stimulus, and that the balance of these adaptations is to some extent dependent upon the intensity and duration of the training protocol used.
The purpose of this study was to compare changes in maximal strength, power, and muscular endurance after 12 wk of periodized heavy-resistance training directly supervised by a personal trainer (SUP) versus unsupervised training (UNSUP).
Twenty moderately trained men aged 24.6 +/- 1.0 yr (mean +/- SE) were randomly assigned to either the SUP group (N = 10) or the UNSUP group (N = 8). Both groups performed identical linear periodized resistance training programs consisting of preparatory (10-12 repetitions maximum (RM)), hypertrophy (8 to 10-RM), strength (5 to 8-RM), and peaking phases (3 to 6-RM) using free-weight and variable-resistance machine exercises. Subjects were tested for maximal squat and bench press strength (1-RM), squat jump power output, bench press muscular endurance, and body composition at week 0 and after 12 wk of training.
Mean training loads (kg per set) per week were significantly (P < 0.05) greater in the SUP group than the UNSUP group at weeks 7 through 11 for the squat, and weeks 3 and 7 through 12 for the bench press exercises. The rates of increase (slope) of squat and bench press kg per set were significantly greater in the SUP group. Maximal squat and bench press strength were significantly greater at week 12 in the SUP group. Squat and bench press 1-RM, and mean and peak power output increased significantly after training in both groups. Relative local muscular endurance (80% of 1-RM) was not compromised in either group despite significantly greater loads utilized in bench press muscular endurance testing after training. Body mass, fat mass, and fat-free mass increased significantly after training in the SUP group.
Directly supervised, heavy-resistance training in moderately trained men resulted in a greater rate of training load increase and magnitude which resulted in greater maximal strength gains compared with unsupervised training.
The purpose of this study was to investigate the effect of high-intensity and low-intensity resistance training upon bone mineral density (BMD) by comparing the BMD of young male powerlifters (n = 5), recreational trainees (n = 5), and controls (n = 5). Lumbar spine (L2-L4), proximal femur, and whole body BMDs were measured using dual-energy X-ray absorptiometry (DXA). The high-intensity group showed a significantly greater BMD when the whole body and trochanter regions were measured than the low-intensity and control group. The BMD of the lumbar spine, femoral neck, and Ward's triangle was greater in the high-intensity group compared with the control group. There was no significant BMD difference between the low-intensity and control group except at the trochanter region. These results suggest that high-intensity resistance training is effective for increasing BMD, but low-intensity resistance training is not.
This investigation compared ratings of perceived exertion specific to the active muscles used during resistance exercise (RPE-AM) using the 15-category Borg scale during high-intensity (HIP) and low-intensity (LIP) weight lifting. Ten men (23.2 +/- 3.6 years) and 10 women (21.8 +/- 2.7 years) performed 2 trials consisting of seven exercises: bench press (BP), leg press, latissimus dorsi pull down, triceps press, biceps curl, shoulder press, and calf raise. The HIP and LIP protocols were completed in counterbalanced order. During HIP, subjects completed 5 repetitions using 90% of 1 repetition maximum (1RM). RPE-AM was measured after every repetition. During LIP, subjects completed 15 repetitions using 30% of 1RM. RPE-AM was measured after every third repetition. RPE-AMs were greater (p <or= 0.001) for HIP than for LIP for each exercise. For example, the mean initial BP RPE was 14.11 +/- 2.08 for the HIP and 8.34 +/- 1.35 for the LIP. Performing few repetitions using heavier weight is perceived to be more difficult than lifting comparatively lighter weight with more repetitions when external work is held constant.
Resistance training is recommended by national health organizations for incorporation into a comprehensive fitness program that includes aerobic and flexibility exercise. Its potential benefits on health and performance are numerous; it has been shown to reduce body fat, increase basal metabolic rate, decrease blood pressure and the cardiovascular demands to exercise, improve blood lipid profiles, glucose tolerance, and insulin sensitivity, increase muscle and connective tissue cross-sectional area, improve functional capacity, and relieve low back pain. Many improvements in physical function and athletic performance are associated with the increases in muscle strength, power, endurance, and hypertrophy observed during resistance training. The key element to effective resistance training is supervision by a qualified professional and the proper prescription of the program variables. Proper program design, ie, that which uses progressive overload, variation, and specificity, is essential to maximize the benefits associated with resistance training.
Progression in resistance training is a dynamic process that requires an exercise prescription process, evaluation of training progress, and careful development of target goals. The process starts with the determination of individual needs and training goals. This involves decisions regarding questions as to what muscles must be trained, injury prevention sites, metabolic demands of target training goals, etc. The single workout must then be designed reflecting these targeted program goals including the choice of exercises, order of exercise, amount of rest used between sets and exercises, number of repetitions and sets used for each exercise, and the intensity of each exercise. For progression, these variables must then be varied over time and the exercise prescription altered to maintain or advance specific training goals and to avoid overtraining. A careful system of goal targeting, exercise testing, proper exercise technique, supervision, and optimal exercise prescription all contribute to the successful implementation of a resistance training program.
The purpose of this study was to determine the intensity of self-selected weightlifting exercise in untrained men and women. Thirteen men (age = 19.5 +/- 1.9, height = 70.0 +/- 2.4 in., weight = 174 +/- 20.1 lb, % fat = 14.3 +/- 6.7) and 17 women (age =18.7 +/- 1.0, height = 64.9 +/- 2.3 in., weight = 135.4 +/- 22.8 lb, % fat= 23.4 +/- 4.7) who were novice lifters completed seated bench press, leg extension, seated back row, military press, and biceps curl. Following self-selection trials, subjects' 1 repetition maximum (1RM) was assessed for each lift. Results showed that for both genders, self-selected loads were all below 60% 1RM. All lift intensities were similar for men and women (range = 42-57% 1RM). Repetitions completed and rating of perceived exertion responses were not different between gender. Results show that subjects do not select a lifting intensity sufficient to induce hypertrophic responses and subsequent strength increases.
The purpose of the present study was to examine differences in ratings of perceived exertion (RPE) and the weight lifted (training load) during self-selected and imposed-intensity bouts of acute resistance exercise (RE). Nineteen untrained college-aged women completed 2 bouts of acute resistance exercise. During 1 session, 3 sets of 4 exercises were performed using a training load of 75% of 1 repetition maximum. Conversely, during the other session, each set and exercise were completed using a self-selected training load. Assessments of RPE and training load were obtained following each set during both imposed-intensity and self-selected-intensity sessions. Results of 2 (intensity) x 3 (set) repeated measures multivariate analyses of variance revealed that, when compared to self-selected RE, RPE and resistance used were significantly higher and the number of repetitions completed per set was significantly lower during imposed-intensity RE. These findings demonstrate that the training load and perceptions of effort elicited during conventional RE prescriptions differ from the level of exertion untrained women self-select. Additionally, it appears that untrained women may not self-select a relative intensity sufficient to stimulate meaningful improvements in muscular hypertrophy or strength. The implications of these findings for the adoption and maintenance of resistance exercise participation are discussed.
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