This study examined the effects of long-term creatine supplementation combined with resistance training (RT) on the one-repetition maximum (1RM) strength, motor functional performance (e.g., 30-s chair stand, arm curl, and getting up from lying on the floor tests) and body composition (e.g., fat-free mass, muscle mass, and % body fat using DEXA scans) in older women. Eighteen healthy women (64.9 ± 5.0 years) were randomly assigned in a double-blind fashion to either a creatine (CR, N = 9) or placebo (PL, N = 9) group. Both groups underwent a 12-week RT program (3 days week(-1)), consuming an equivalent amount of either creatine (5.0 g day(-1)) or placebo (maltodextrin). After 12 week, the CR group experienced a greater (P < 0.05) increase (Δ%) in training volume (+164.2), and 1RM bench press (+5.1), knee extension (+3.9) and biceps curl (+8.8) performance than the PL group. Furthermore, CR group gained significantly more fat-free mass (+3.2) and muscle mass (+2.8) and were more efficient in performing submaximal-strength functional tests than the PL group. No changes (P > 0.05) in body mass or % body fat were observed from pre- to post-test in either group. These results indicate that long-term creatine supplementation combined with RT improves the ability to perform submaximal-strength functional tasks and promotes a greater increase in maximal strength, fat-free mass and muscle mass in older women.

The purpose of this study was to investigate the effect of resistance training on resting blood pressure and heart rate variability in elderly postmenopausal women. 29 untrained, non-hypertensive elderly women were randomly assigned to 2 groups: an intervention group (n=15, 65.5±5.0 years, 57.3±6.5 kg, 156.7±5.1 cm) that underwent a supervised resistance training program (8 exercises, 2 sets, 10-15 repetitions, 3 times/week) or a control group (n=14, 66.2±4.1 years, 61.1±11.7 kg, 157.5±7.1 cm) that participated in a supervised stretching program (25-30 min/session, 2 times/week). Resting auscultatory blood pressure, heart rate variability, evaluated from short recordings in a seated position, and maximal dynamic strength (1-RM test) were measured at baseline and after 12 weeks. A group x time ANOVA revealed that muscular strength increased significantly in the resistance training group (+ 10.2% for bench press and +12.7% for leg extension, P<0.05). Systolic blood pressure was reduced significantly in the resistance training group from pre- to post-intervention period (- 5 mmHg; P<0.05), while no significant effect was noted for diastolic blood pressure and heart rate variability indexes (P>0.05). None of these variables changed in the control group throughout the study. In conclusion, a supervised resistance training program improved muscular strength and reduced systolic blood pressure without affecting diastolic blood pressure and heart rate variability in elderly postmenopausal women.

Strength is a fundamental component of physical fitness, and therefore should be precisely assessed. The purpose of this study was to analyze the number of testing sessions required to achieve consistent 1 repetition maximum (1RM) strength measurements in untrained older women. Forty-five untrained older women were measured for 1RM in bench press machine (BP), leg extension (LE) machine, and free weight arm curl (AC). Reliability coefficients for trials 1 and 2 for BP (intraclass correlation coefficient [ICC] = 0.973) and LE (ICC = 0.976) were higher than for AC (ICC = 0.953). Percent change from trial 1 to 2 for BP (3.5 ± 10.9%) and AC (3.8 ± 8.1%) was less than for LE (5.4 ± 6.2%), but all were significant increases between trials (p < 0.05). Trial differences were reduced to nonsignificant levels (p > 0.05) in the third trial for BP (0.0 ± 0.0%), LE (1.2 ± 3.0%) and AC (2.7 ± 5.9%). Reliability coefficients rose for BP and LE (ICC = 0.999) and AC (ICC = 0.963) when a third trial was performed. Bland and Altman plotting showed very small bias and limits of agreement (LoA) for both the exercises (BP: bias = 0 kg, limits of agreement = 0 kg; LE: bias = -0.16 kg, LoA = 2.21 kg; AC: bias = -0.11 kg, LoA = 1.72 kg). This approach to determine 1RM strength values produced rapid lifting technique familiarization resulting in a need of 2 to 3 test sessions to achieve consistent 1RM measurements in untrained older women.

BackgroundTo determine the effects of a low dose, short-term Creatine monohydrate (Cr) supplementation (0.03 g.kg.d−1 during 14 d) on muscle power output in elite youth soccer players.MethodsUsing a two-group matched, double blind, placebo-controlled design, nineteen male soccer players (mean age = 17.0 ± 0.5 years) were randomly assigned to either Cr (N = 9) or placebo (N = 10) group. Before and after supplementation, participants performed a 30s Wingate Anaerobic Test (WAnT) to assess peak power output (PPO), mean power output (MPO), fatigue index (FI), and total work.ResultsThere were significant increases in both PPO and MPO after the Cr supplementation period (P ≤ 0.05) but not the placebo period. There were also significant increases in total work, but not FI, after the Cr supplementation and placebo periods (P ≤ 0.05). Notably, there were differences in total work between the Cr and placebo groups after (P ≤ 0.05) but not before the 14 d supplementation period.ConclusionThere is substantial evidence to indicate that a low-dose, short-term oral Cr supplementation beneficially affected muscle power output in elite youth soccer players.