Upper-Extremity Explosive Resistance Training With Older Adults Can Be Regulated Using the Rating of Perceived Exertion.

Row Lazzarini, BR, Dropp, M, and Lloyd, W. Upper-extremity explosive resistance training with older adults can be regulated using the rating of perceived exertion. J Strength Cond Res 31(3): 831-836, 2017-Explosive resistance training (ERT) improves muscle strength and power in older adults. Previous work has determined that the Borg rating of perceived exertion (RPE) scale can be used to regulate ERT loads for older adults on the leg press exercise. The purpose of this study was to assess the relationship between the Borg RPE scale and ERT loads relative to the 1 repetition maximum (%1RM) in older adults during the chest press exercise. Healthy seniors (n = 10 men, mean [SD] age 75.8 [7.9]; n = 10 women, age 73.0 [6.3]) took part in 2 sessions on nonconsecutive days. During the first session, subjects reported their RPE during multiple ERT repetitions on the chest press for 7 loads across the spectrum of "light" to "heavy", ranging from 20 to 105% body weight. The loads, concealed from the participants, were presented in randomized order. During the second session, a 1RM strength test was conducted. Each load experienced on the first visit was calculated as %1RM. Rating of perceived exertion was averaged across subjects for each 5% range of 1RM from 35% 1RM to 110% 1RM. Regression analysis was used to determine if RPE predicts %1RM during chest press ERT. Rating of perceived exertion predicted the %1RM corresponding with chest press ERT loads (R = 97.6%, SEE 3.6, p < 0.001). Loads that would elicit both strength and power gains (70-90% 1RM) corresponded with an RPE of 14-17. As previously demonstrated with the leg press, ERT loads can be regulated for older adults during the chest press using RPE, allowing ERT to be conducted without maximal strength testing. This approach may increase the adoption of this training method for a broader spectrum of seniors.

Treadmill walking is not equivalent to overground walking for the study of walking smoothness and rhythmicity in older adults.

Treadmills are appealing for gait studies, but some gait mechanics are disrupted during treadmill walking. The purpose of this study was to examine the effects of speed and treadmill walking on walking smoothness and rhythmicity of 40 men and women between the ages of 70-96 years. Gait smoothness was examined during overground (OG) and treadmill (TM) walking by calculating the harmonic ratio from linear accelerations measured at the level of the lumbar spine. Rhythmicity was quantified as the stride time standard deviation. TM walking was performed at two speeds: a speed matching the natural OG walk speed (TM-OG), and a preferred TM speed (PTM). A dual-task OG condition (OG-DT) was evaluated to determine if TM walking posed a similar cognitive challenge. Statistical analysis included a one-way Analysis of Variance with Bonferroni corrected post hoc comparisons and the Wilcoxon signed rank test for non-normally distributed variables. Average PTM speed was slower than OG. Compared to OG, those who could reach the TM-OG speed (74.3% of sample) exhibited improved ML smoothness and rhythmicity, and the slower PTM caused worsened vertical and AP smoothness, but did not affect rhythmicity. PTM disrupted smoothness and rhythmicity differently than the OG-DT condition, likely due to reduced speed. The use of treadmills for gait smoothness and rhythmicity studies in older adults is problematic; some participants will not achieve OG speed during TM walking, walking at the TM-OG speed artificially improves rhythmicity and ML smoothness, and walking at the slower PTM speed worsens vertical and AP gait smoothness.