Perceived Exertion As A Monitoring Strategy During Crossfit®

Abstract

Facing harsh criticism of potentially causing injury, CrossFit® (CF) may benefit from the inclusion of appropriate monitoring strategies. Rate of perceived exertion (RPE) is a monitoring strategy commonly used for both quantification and modulation of workloads during exercise and sports training. Despite its widespread use in CF investigations, the validity of RPE as a monitoring strategy in CF training remains untested. PURPOSE: To assess the utility of RPE as a monitoring strategy during CF training. METHODS: Six males (height, 182.8±8.6 cm; weight, 84.3±12.4 kg; and age, 25.0±5.4 years) participated in three weeks (5 days/week) of CF training. Following each training session, RPE, workout duration (Dura), and immediate post-exercise heart rate (THR) were recorded. Dura and THR were used to quantify the workload (WL) for each session. Means for RPE, Dura, THR, and WL were calculated for week 1 and week 3 of training. The Profile of Mood States (POMS) questionnaire was administered pre-week 1 and post- week 3. A repeated measures MANOVA with Tukey post-hoc adjustments was used to assess differences in training session variables between weeks 1 and 3. Linear regression of mean RPE and WL were compared between weeks 1 and 3. POMS outcomes were compared between weeks 1 and 3 using magnitude-based inferences of each subscales’ minimum clinically important difference (MCID). RESULTS: There are increases in mean session THR (%Δ=+6.2%; F=1.19, p=0.324), Dura (%Δ=+17.3%; F=4.55, p=0.086), and WL (%Δ=+23.9%; F=8.14, p=0.036) from week 1 to 3. In contrast, mean session RPE decreased (%Δ=-4.9%; F=1.42, p=0.183) between these weeks. RPE was a better predictor of WL during week 3 compared to week 1 (week 1: r=0.364, R2=13.5%, p=0.048; week 3: r=0.614, R2=37.7%, p=0.001; ΔR2=+24.2%). For POMS outcomes, total mood disturbance (2.69 foldΔ; 87.6% likelihood), tension-anxiety (3.13 foldΔ; 90.7% likelihood), and vigor-activity (3.25 foldΔ; 94.9% likelihood) subscales most likely highlight meaningful negative changes. CONCLUSION: RPE has the potential to be a useful monitoring strategy for incorporation into CF training. Questions still remain as to whether or not RPE is sensitive enough to detect early signs of overreaching during CF training.