Decline in Unintentional Lifting Velocity Is Both Load and Exercise Specific.

Beck, M, Varner, W, LeVault, L, Boring, J, and Fahs, CA. Decline in unintentional lifting velocity is both load and exercise specific. J Strength Cond Res 34(10): 2709-2714, 2020-When monitoring the mean concentric velocity (MCV) for velocity-based resistance training, often a threshold in the decline in the MCV is used to regulate the number of repetitions performed. However, it is not clear if the decline in the MCV is affected by the type of exercise or the relative load used. Therefore, the purpose of this study was to compare the decline in the MCV between the overhead press (OHP) and deadlift (DL) during sets to fatigue at different loads. Thirty individuals (23 ± 3 years) with current training experience with both the OHP and DL completed a 1 repetition maximum (1RM) protocol for the OHP and DL. Subjects then returned to the laboratory on 2 separate occasions and completed 1 set of the OHP and DL to volitional fatigue at either 70 or 90% of their 1RM in a randomized order. The open barbell system measured the MCV of all repetitions. The absolute and relative (%) decline in the MCV was calculated for each condition and compared between loads (70 vs. 90% 1RM) and between lifts (OHP vs. DL). An alpha level of 0.05 was used at the criterion for statistical significance. The absolute decline in the MCV was greatest for the 70% OHP condition (0.36 ± 0.12 m·s) followed by 90% OHP (0.19 ± 0.10 m·s), 70% DL (0.16 ± 0.08 m·s), and 90% DL (0.09 ± 0.06 m·s); all were significantly different from one another (p < 0.05) except for 70% DL vs. 90% OHP (p = 0.441). There was a greater relative decline in the MCV for the OHP compared with the DL (50.1 ± 11.8% vs. 28.5 ± 11.8%; p < 0.001) and for 70% 1RM compared with 90% 1RM (44.5 ± 12.0% vs. 34.1 ± 12.0%; p < 0.001). These data suggest the decline in the MCV is both exercise and load specific. Applying a uniform velocity decline threshold for velocity-based training may reduce training volume to different extents depending on the exercise and relative load used.

The accuracy of commercially available upper and lower body bioelectrical impedance analyzers in men and women.

OBJECTIVE: The purpose of this study was to determine if upper body (UB) and lower body (LB) bioelectrical impedance analysis (BIA) devices yield similar estimates of BF% as whole body (WB) BIA. APPROACH: Ninety-four men and women had their body composition evaluated using a Baseline 12-1190 Body Fat Scale (Fabrication Enterprises Inc.) as the LB BIA device, an Omron HBF-306C Handheld Body Fat Loss Monitor (Omron Healthcare, Inc.) as the UB BIA device, and a Seca Medical Body Composition Analyzer 514 (Seca North America) as the WB BIA device as well as via air displacement plethysmography (ADP; BodPod; Life Measurement Inc.). MAIN RESULTS: in women, the BF% was greater for WB BIA compared to UB BIA and LB BIA (28.9 ± 5.0 versus 23.8 ± 4.4 versus 20.4 ± 5.9%; p < 0.001) with no differences between the WB BIA and ADP BF% (28.9 ± 5.0 versus 28.3 ± 7.5%; p = 0.982). In men, BF% was greater for WB BIA compared to UB BIA and LB BIA (19.1 ± 6.7 versus 15.5 ± 5.3 versus 14.9 ± 4.0; p < 0.001) with no differences between the WB BIA and ADP BF% (19.1 ± 6.7 versus 17.6 ± 7.8; p = 0.394). SIGNIFICANCE: Our findings suggest that the UB and LB BIA devices used in this study underestimate BF% compared to a WB BIA device and ADP in men and women.