Author(s): ASSELIN, W., TREMBLAY, R., LEBEL, K., LANDRY, C., PAGEAUX, B., MAMPUYA, W.M., O'BRIEN, M.W., RIESCO, E., Institution: UNIVERSITÉ DE SHERBROOKE, Country: CANADA, Abstract-ID: 2184

INTRODUCTION:
Resistance exercise (RE) is recommended to preserve muscle strength in aging women and can be performed using a wide range of external loads (percentage of one-repetition maximum: %1-RM). When low loads are used, reaching a high effort intensity (i.e., close to momentary muscular failure) requires a greater number of repetitions, which may reduce enjoyment and potentially compromise long-term adherence. In this context, it remains unclear whether low- and high-load RE performed at high effort intensity elicit different affective and enjoyment responses in inactive aging females.
Objective: The aim of this study is to compare affective valence and enjoyment responses between low- and high-load RE when proximity to momentary muscular failure is standardized in aging females.
METHODS:
Thirty-six post-menopausal inactive females (50-70 years) are enrolled in a randomized controlled crossover study including two RE conditions: 1) High-load RE (80% 1-RM; HL-RE) and 2) Low-load RE (50% 1-RM; LL-RE). Both conditions are performed at a standardized effort intensity corresponding to 2 repetitions in reserve (RIR) before reaching momentary muscular failure. Affective valence is assessed after each set using the Feeling Scale (FS range −5 to +5). Exercise enjoyment is assessed 5 min after the last exercise using the Physical Activity Enjoyment Scale (max score: 126 corresponding to high enjoyment).
RESULTS:
Preliminary analyses (n=7) indicate no significant differences in affective valence between LL-RE and HL-RE across sets and exercises (p ≥ 0.09). For LL-RE, median FS values were as follows: leg press: 3 [1–3] to 3 [1–4]; chest press: 3 [2–3] to 3 [3–5]; leg curl: 3 [0–4] to 3 [2–5]; close grip pull-down: 3 [1–3] to 3 [2–3]. For HL-RE, median FS values were: leg press: 3 [1–5] to 3 [3–5]; chest press: 2 [2–5] to 2 [1–5]; leg curl: 3 [2–5] to 3 [2–5]; close grip pull-down 3 [2–3] to 3 [2–3]. Exercise enjoyment assessed by PACES did not differ between conditions (91 [82-106] vs. 95 [88-110]; p ≥ 0.28).
CONCLUSION:
These preliminary findings suggest that RE performed with low- or high-external loads elicits comparable affective responses and enjoyment when effort intensity is standardized near to muscle failure. These findings suggest that, in inactive post-menopausal females, external load per se may not be a key determinant of enjoyment during RE when effort intensity is standardized near muscular failure. Completion of the full study sample will allow confirmation of these observations.