1 Départment des sciences de l'activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada.
2 Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montréal, Québec, Canada.
3 Department of Health, Kinesiology and Applied Physiology, PERFORM Centre and Center for Studies in Behavioral Neurobiology, Concordia University, Montréal, Québec, Canada.
4 Department of Physiotherapy, Laval University, Québec city, Québec, Canada.
5 Department of Psychology, Concordia University, Montréal, Québec, Canada.
6 Faculté de médecine, École de kinésiologie et des sciences de l'activité physique (EKSAP), Université de Montréal, Montréal, Québec, Canada.
7 Départment des sciences de l'activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, Québec, Canada. aubertin-leheudre.mylene@uqam.ca.
8 Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montréal, Québec, Canada. aubertin-leheudre.mylene@uqam.ca.

Background: Recorded and live online physical exercise (PE) interventions are known to provide health benefits. However, the effects of prioritizing the number of live or recorded sessions remain unclear.

Aims: To explore which recorded-live sessions ratio leads to the best implementation and benefits in older adults.

Methods: Forty-six community-dwelling adults (> 60y.o.) were randomized into two groups completing a 12-week online PE intervention. Each group had a different ratio of live-recorded online sessions as follows: Live-Recorded-Live sessions (LRL; n = 22) vs. Recorded-Live-Recorded sessions (RLR; n = 24).

Results: Drop-out rates did not reach significance (LRL:14% vs. RLR: 29%, p = 0.20), and adherence was similar (> 85%) between groups. Both groups reported similar levels of satisfaction (> 70%), enjoyment (> 75%), and perceived exertion (> 60%). Both groups increased physical health and functional capacities, with greater improvements in muscle power (LRL: LRL: + 35 ± 16.1% vs. RLR: + 7 ± 13.9%; p = 0.010) and endurance (LRL: + 34.7 ± 15.4 vs. RLR: + 27.0 ± 26.5, p < 0.001) in the LRL group.

Discussion: Both online PE intervention modalities were adapted to the participants' capacities and led to a high level of enjoyment and retention. The greater physical improvements observed in the LRL group are likely due to the higher presence of the instructor compared to the RLR group. Indeed, participants received likely more feedback to appropriately adjust postures and movements, increasing the quality of the exercises.

Conclusion: When creating online PE interventions containing both recorded and live sessions, priority should be given to maximizing the number of live sessions and not the number of recorded sessions.