Can the effects of implementation intentions on exercise be enhanced using text messages?

Implementation intentions planning in advance the situation in which one will act, have been proposed to be an effective self-regulatory technique for changing health behaviour. Encouraging people to receive text message reminders of their implementation intentions should enhance their strength and, thus, it was predicted that this combined approach would be particularly effective in increasing exercise. Participants (N = 155) were randomly allocated to one of five conditions (implementation intentions and SMS, implementation intention, SMS or one of two control groups) then completed self-report measures of exercise behaviour and motivation. Four weeks later, they responded to similar items. Results suggested that the combined intervention increased exercise frequency significantly more than the other strategies including the implementation intention group. It is proposed, therefore, that implementation intention effects can be enhanced via plan reminders.