Site-­specific thigh muscle loss may be independent of age-­related whole body muscle mass loss detected by using dual-­ energy X-­ray absorpotiometry (DXA). Site-­specific thigh muscle loss can be assessed by two major methods, i.e., magnetic resonance imaging (MRI) or computed tomography (CT) and ultrasound. Objectives: The purpose of this review is to discuss whether the magnitude of age-­related declines in anterior and posterior thigh muscle size differs among previous studies with different methods for assessing muscle size. Age-­related changes in absolute and relative knee extension (KE) and flexion (KF) strength and possible reasons for the age-­related site-­spe-­ cific thigh muscle loss are discussed. Design and Method: Non-­systematic review. Results: The results of MRI/CT and ultrasound studies both suggest that age-­related thigh muscle loss differs between the anterior compartment (i.e., quadriceps) and posterior compartment (i.e., hamstring) with much larger losses occurring in the anterior thigh compared with the posterior thigh. Previous studies investigating the age-­related changes in absolute KE and KF strength are not as consistent. However, age-­related change in muscle quality (strength per unit of muscle size) may not differ between KE and KF in an individual, although the values may differ among individuals. A major reason for the site-­specific thigh muscle loss with advancing age may be the intensity and duration of daily physical activity which may secondarily influence other factors such as motoneuron loss and muscle protein metabolism. Conclusions: A ratio of anterior to posterior MT determined by ultrasound may correspond well to a multidimensional vari-­ able (CSA or MV) of the quadriceps to other thigh muscles (including both hamstring and adductor muscles) ratio, but not to the quadriceps to hamstring ratio. If there are similar changes in muscle quality with advancing age between knee extensor and flexor muscles, the anterior to posterior MT ratio may be involved in a ratio of muscle force of knee exten-­ sor and flexor muscles.

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Objectives: The purpose of this study was to investigate the effects of intensity on rating of perceived exertion (RPE) during multiple sets to volitional failure in bench press exercise. Design and Methods: Thirteen moderately resistance trained men performed 2 experimental sessions in random order: 3 sets to failure in bench press with 1 minute rest at an intensity of 50% and 70% of 1 repetition maximum (1RM). RPE was measured using the OMNI scale after each set. Readiness to Invest in Physical (RTIPE) and Mental (RTIME) Effort were assessed before each set. Results: Repetitions to failure (46.46 ± 9.43 vs 26.62 ± 8.19; P<0.001) and total weight lifted (2044.31 ± 414.5 vs 1650.15 ± 507.83 kg; P<0.001) were greater at 50% when compared to the 70% 1RM condition. There were no differences in RPE, RTIPE, RTIME and heart rate across conditions. Conclusions: These results indicate that when repetitions are done to volitional failure, monitoring RPE is not a useful tech nique in regulating intensity during resistance training.

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Objectives: This study aimed to compare one repetition maximum (1RM) power clean performances, performed from the floor, the knee and from mid-thigh, to determine the differences between variations. Design and Methods: Using a within subjects repeated measures design, healthy male subjects (n=12; height 1.83 ± 0.08 m; body mass 92.17 ± 13.18 kg; age 21 ± 3.69 years), performed each variation of the power clean on two separate occasions to determine reliability of each assessment. A repeated measures ANOVA with Bonferroni post hoc analysis was used to compare performances between each variation. Results: Power clean from the floor (93.75 ± 16.53 kg) resulted in significantly greater loads lifted than the power clean from the knee (87.92 ± 16.85 kg, p=0.04, Cohens d = 0.35) and the mid-thigh power clean (87.33 ± 16.43 kg, p=0.02, Cohens d = 0.53). There was no significant difference between the power clean from the knee and mid-thigh power clean (p>0.05, Cohens d = 0.15). Coefficient of determination between the power clean and the power clean performed from the knee (R² = 0.923) and mid-thigh power clean (R² = 0.923) were high. Conclusion: From the findings of this study, when maximal load is required, the power clean from the floor permits the use of the greatest load, which can be used to predict the 1RM of the other variations. Moreover, when determining changes in performance in each variation of the lift, changes ≥6.14%, ≥7.18% and ≥7.66% for the power clean, power clean from the knee and power clean from mid-thigh, respectively, can be considered meaningful changes.

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