The effects of amino acid supplementation on hormonal responses to resistance training overreaching.
The purpose of this investigation was to examine the effects of amino acid supplementation on muscular performance and resting hormone concentrations during resistance training overreaching. Seventeen resistance-trained men were randomly assigned to either an amino acid (AA) or a placebo (P) group and underwent 4 weeks of total-body resistance training designed to induce a state of overreaching. The protocol consisted of two 2-week phases (phase 1, 3 sets of 8 exercises performed for 8-12 repetitions; phase 2, 5 sets of 5 exercises performed for 3-5 repetitions). Muscle strength and resting blood samples were determined before (T1) and at the end of each training week (T2-T5). One-repetitio…
Changes in myosin heavy chain composition with heavy resistance training in 60- to 75-year-old men and women.
The purpose of this investigation was to assess the myosin heavy chain (MHC) expression in the vastus lateralis muscle from elderly men and women, and to determine whether heavy resistance training influences its expression. Twenty healthy, mildly physically active subjects gave their informed consent to participate in the study. The experimental group consisted of seven men and seven women [mean (SD) age 65.5 (4.1) years] and the control group consisted of three men and three women [mean (SD) age 62.3 (3.6) years]. The 6-month resistance training program was divided into two phases with weeks 1-12 consisting of high-intensity resistance training, and weeks 13-24 involving power training. M…
Effects of heavy resistance/power training on maximal strength, muscle morphology, and hormonal response patterns in 60-75-year-old men and women.
Eleven women (TRW; 64 ± 4 yrs) and ten men (TRM; 65 ± 5 yrs) participated in the strength/power training twice a week for 24 weeks. Basal concentrations of serum total and free testosterone, growth hormone (GH), dehydroepiandrosterone sulfate (DHEAS), cortisol and sex hormone binding globulin (SHBG) as well as acute responses of serum total and free testosterone, growth hormone (GH) were measured. Maximal 1RM strength in the squat, chair rise time and muscle fibre distribution and areas of type I and IIa and IIb of the vastus lateralis were also examined. 1RM squat increased in TRW by 26 (SDIO) % (p < .001), and in TRM by 35(7) % (p < .001) and chair rise time improved in both groups…
Neuromuscular responses to explosive and heavy resistance loading
The EMG power spectrum may shift towards higher frequencies with higher movement velocities. Fatigue, on the other hand, can cause a decrease in the frequency components. The purpose of this study was to examine acute effects of explosive (EE) and heavy resistance (HRE) concentric leg press exercise on muscle force, EMG and blood lactate. The EE included five sets of ten repetitions with 40+/-6% of the isometric maximum at a 100 degrees knee angle performed as explosively as possible. The same number of repetitions was performed in HRE but with a heavier load (67+/-7% of the isometric maximum at a 100 degrees knee angle). Maximal isometric and single concentric actions of different loads, a…
Endogenous opioid peptide responses to opioid and anti-inflammatory medications following eccentric exercise-induced muscle damage.
To determine the effects of Vicoprofen, Ibuprofen, and a placebo on the responses of endogenous opioid peptides following eccentric exercise-induced muscle damage 36 healthy men (age: 22.8 years; height: 178.8+/-6.2cm; body mass: 78.9+/-13.7kg; body fat: 15.8+/-6.5%) volunteered to participate in the study. Each participant was evaluated for pain 24h post and randomly assigned to an experimental group: VIC (Vicoprofen), IBU (Ibuprofen), or P (placebo). Medication was given four times daily (i.e., VIC (hydrocodone bitartrate 7.5mg with Ibuprofen 200mg) and IBU 200mg). Blood was obtained at rest and at 0, 24, 48, 72, 96 and 120h following the eccentric exercise damage protocol. No significant…