Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Affective response to acute resistance exercise: a comparison among machines and free weights

Purpose This study aimed at investigating enjoyment, affective states (affective valence and perceived activation), and perceived exertion during acute resistance exercise with machines or free weights. Methods Thirty recreationally strength-trained males performed two training sessions on 2 separate days using a descending pyramid training system, one performed with three machines (chest press, shoulder press machine and leg press) and the other with three free weight exercises (bench press, front military press and squat). The Physical Activity Enjoyment Scale, the Borg Scale for Rating of Perceived Exertion, the Feeling Scale, and the Felt Arousal Scale were administered at the end of each session. Results Analyses revealed higher scores on all the variables when participants exercised with free weights (p < 0.001). Enjoyment was positively related to perceived exertion only in the free weight session (r = 0.45; p < 0.01). When looking at the circumplex model of affect, results showed that resistance exercise performed with free weights resulted in a pleasant activation feeling for all participants, while the machine training condition determined high-activation pleasant state for the majority but also cases of low-activation, displeasure state. Conclusions Resistance training with free weights resulted in increased pleasantness and activation compared with machine training. The establishment of resistance training programmes should consider, close to physiological and technical aspects, also the affective response to different modalities of exercise, particularly when the aim is improving the general fitness