Development of a neuromuscular electrical stimulation protocol for sprint training.

Purpose: Sprint training is associated with several beneficial adaptations in skeletal muscle, including an enhancement of sarcoplasmic reticulum (SR) Ca(2+) release. Unfortunately, several patient populations (e.g.

Early-phase muscular adaptations in response to slow-speed versus traditional resistance-training regimens.

Thirty-four untrained women participated in a 6-week program to investigate slow-speed versus "normal" speed resistance-training protocols. Subjects were divided into: slow-speed (SS), normal-speed/traditional-strength (TS), normal-speed/traditional muscular endurance (TE), and non-exercising control (C) groups. Leg press, squats, and knee extensions were performed 2 days/week for the first week and 3 days/week for the remaining 5 weeks (~2 min rest).

Differences in cardiac parameters among elite rowers and subelite rowers.

Unlabelled: There is significant individual variability in the cardiac adaptation that occurs in response to exercise training. Factors associated with this variability remain incompletely understood. To date, the relationship between the competition level at which athletes participate and their underlying cardiac parameters has not been explored.

Comparison of early phase adaptations for traditional strength and endurance, and low velocity resistance training programs in college-aged women.

The purpose of this study was to investigate the effects of a six-week (16-17 training sessions) low velocity resistance training program (LV) on various performance measures as compared to a traditional strength (TS) and a traditional muscular endurance (TE) resistance training program. Thirty-four healthy adult females (21.1 +/- 2.

Exercise responses and adaptations in rowers and spinal cord injury individuals.

Elite rowers (ROWERS) and those who have had a spinal cord injury (SCI) are different physically in many realms. Both have physical activity histories that affect their lower-extremity extensor muscles in a dramatically different fashion. ROWERS can sustain a 500-W power output during their 5- to 6-min race.

Muscle fiber characteristics and performance correlates of male Olympic-style weightlifters.

Biopsies fro the vastus lateralis muscle of male weightlifters (WL; n=6; X +/- SE, age=27.0 +/- 2.1 years), and non-weight-trained men (CON; n=7; age=27.

The Effects of Low-Dose Creatine Supplementation Versus Creatine Loading in Collegiate Football Players.

OBJECTIVE: To compare the effects of low doses of creatine and creatine loading on strength, urinary creatinine concentration, and percentage of body fat. DESIGN AND SETTING: Division IA collegiate football players took creatine monohydrate for 10 weeks during a sport-specific, periodized, off-season strength and conditioning program. One-repetition maximum (1-RM) squat, urinary creatinine concentrations, and percentage of body fat were analyzed.

Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones.

Thirty-two untrained men [mean (SD) age 22.5 (5.8) years, height 178.

The effects of a 10-week, periodized, off-season resistance-training program and creatine supplementation among collegiate football players.

The periodized resistance-training model has not been well documented in the literature. Further research is needed to determine if periodized resistance training in conjunction with creatine supplementation can cause changes in strength, performance, total body weight, girth, and lean muscle mass. Therefore, the purpose of this investigation was to determine the effects of periodized resistance training in conjunction with low-dose (LD) and high-dose (HD) creatine supplementation on strength, body composition, and anaerobic muscular endurance.

Human muscle power output during upper- and lower-body exercises.

The purpose of this study was to evaluate the use of traditional resistance training equipment in the measurement of muscular power. This was accomplished by measuring the velocity of movement through a measured distance during maximal effort lifts using a Smith rack. The reliability of the method was established using 10 male volunteers who performed both bench press and squat exercises in a Smith rack.

Creatine supplementation improves muscular performance in older men.

Purpose: Creatine supplementation has been shown to enhance muscle strength and power after only 5-7 d in young adults. Creatine supplementation could therefore benefit older individuals because aging is associated with a decrease in muscle strength and explosive power.

Methods: We examined the effects of 7 d of creatine supplementation in normally active older men (59-72 yr) by using a double-blind, placebo-controlled design with repeated measures.

Skeletal muscle adaptations in elastic resistance-trained young men and women.

Skeletal muscle adaptations (fiber-type composition, cross-sectional area, myosin heavy chain (MHC) content, and capillarity) were assessed in the vastus lateralis muscle of young men and women after 8 weeks of training with the Sportcord, an elastic resistance device. Ten men [mean (SD) age 20 (1.1) years] and 13 women [20 (1.

The effectiveness of 0.5-lb increments in progressive resistance exercise.

A traditional progressive resistance exercise program consists of increasing the number of repetitions at a constant load until exceeding an established repetition range. Subsequently, the load is increased by 1.1 kg (2.

Effects of high-intensity resistance training on untrained older men. II. Muscle fiber characteristics and nucleo-cytoplasmic relationships.

During growth and repair of skeletal muscle fibers, satellite cells become activated, undergo mitosis, and a daughter nucleus becomes incorporated into the muscle fiber to increase myonuclear numbers. An increase in myonuclei appears to be required for this postnatal growth. This study examined whether muscle fibers of elderly men can hypertrophy with strength training and, if so, whether they have the capacity to incorporate nuclei into the fibers.

Effects of high-intensity resistance training on untrained older men. I. Strength, cardiovascular, and metabolic responses.

Most resistance training studies of older subjects have emphasized low-intensity, short-term training programs that have concentrated on strength measurements. The purpose of this study was, in addition to the determination of strength, to assess intramuscular and transport factors that may be associated with strength increments. Eighteen untrained men ages 60-75 years volunteered for the study; 9 were randomly placed in the resistance-training group (RT), and the other half served as untrained (UT) or control subjects.

Fiber type composition of the vastus lateralis muscle of young men and women.

This study presents data collected over the past 10 years on the muscle fiber type composition of the vastus lateralis muscle of young men and women. Biopsies were taken from the vastus lateralis muscle of 55 women (21.2+/-2.

The effects of short-term resistance training on endocrine function in men and women.

This investigation examined hormonal adaptations to acute resistance exercise and determined whether training adaptations are observed within an 8-week period in untrained men and women. The protocol consisted of a 1-week pre-conditioning orientation phase followed by 8 weeks of heavy resistance training. Three lower-limb exercises for the quadriceps femoris muscle group (squat, leg press, knee extension) were performed twice a week (Monday and Friday) with every other Wednesday used for maximal dynamic 1 RM strength testing.

Differential titin isoform expression in human skeletal muscle.

Mammalian skeletal muscle expresses at least two isoforms of the cytoskeletal protein titin (connectin; MW approximately 3000 kDa). These isoforms are associated with different passive force curves, and thus may affect physical performance. To study the distribution of titin and its possible influence on performance in humans, muscle biopsies were obtained from 15 males (mean +/- SE; age = 25.

A 20-yr longitudinal study of Olympic oarsmen.

Nine 1972 silver-medalist oarsmen were studied before the Olympic Games and 10 and 20 yr later. Peak power, metabolic responses, and heart rate were recorded during rowing ergometry; blood lactate was measured following exercise. The skinfold equation yielded percent body fat.

Cardiorespiratory and metabolic adaptations to hyperoxic training.

This study examined the effects of hyperoxic training on specific cardiorespiratory and metabolic responses. A group of 19 male subjects trained for 5 weeks on a cycle ergometer at 70 percent of hyperoxic or normoxic maximal heart rate, the hyperoxic group (HG) breathing 70 percent O2, the normoxic group (NG) breathing 21 percent O2. The subjects were tested pre- and post-training under both hyperoxia and normoxia.

Effects of sprint cycle training on human skeletal muscle.

Eleven men sprint trained two to three times per week for 6 wk to investigate possible exercise-induced slow-to-fast fiber type conversions. Six individuals served as controls. Both groups were tested at the beginning and end of the study to determine anaerobic performance and maximal oxygen consumption.

Skeletal muscle adaptations during early phase of heavy-resistance training in men and women.

An 8-wk progressive resistance training program for the lower extremity was performed twice a week to investigate the time course for skeletal muscle adaptations in men and women. Maximal dynamic strength was tested biweekly. Muscle biopsies were extracted at the beginning and every 2 wk of the study from resistance-trained and from nontrained (control) subjects.

Energy metabolism and fuel utilization.

1) Total energy expenditure during marathon training and competition is among the highest reported for any endurance activity. 2) Although training intensity for the marathon may vary between 60-125% of maximal physical working capacity, elite runners must run consistently at about 80-90% of VO2max in order to achieve successful competitive performances. 3) Earlier studies demonstrated that carbohydrate was the preferential fuel for endurance exercise, but more recent studies have suggested a greater role for lipids than previously thought.

Recovery from exercise-induced desaturation in the quadriceps muscles of elite competitive rowers.

A simple muscle tissue spectrophotometer is adapted to measure the recovery time (TR) for hemoglobin/myoglobin (Hb/Mb) desaturation in the capillary bed of exercising muscle, termed a deoxygenation meter. The use of the instrument for measuring the extent of deoxygenation is presented, but the use of TR avoids difficulties of quantifying Hb/Mb saturation changes. The TR reflects the balance of oxygen delivery and oxygen demand in the localized muscles of the quadriceps following work near maximum voluntary contraction (MVC) in elite male and female rowers (a total of 22) on two occasions, 1 yr apart.

Assessment of skeletal muscle damage in successive biopsies from strength-trained and untrained men and women.

The effects of repeated biopsy sampling on muscle morphology was qualitatively and quantitatively assessed in strength-trained and untrained men and women. College-age men (13) and women (8) resistance trained twice a week for 8 weeks. A progressive resistance-training program was performed consisting of squats, leg presses, and leg extensions.