Recent embodiment research revealed that cognitive processes can be influenced by bodily cues. Some of these cues were found to elicit disparate effects on cognition. For instance, weight sensations can inhibit problem-solving performance, but were shown to increase judgments regarding recall probability (judgments of learning; JOLs) in memory tasks. We investigated the effects of physical effort on learning and metacognition by conducting two studies in which we varied whether a backpack was worn or not while 20 nouns were to be learned. Participants entered a JOL for each word and completed a recall test. Experiment 1 ( = 18) revealed that exerting physical effort by wearing a backpack led to higher JOLs for easy nouns, without a notable effect on difficult nouns. Participants who wore a backpack reached higher recall scores. Therefore, physical effort may act as a form of desirable difficulty during learning. In Experiment 2 ( = 30), the influence of physical effort on JOL s and learning disappeared when more difficult nouns were to be learned, implying that a high cognitive load may diminish bodily effects. These findings suggest that physical effort mainly influences superficial modes of thought and raise doubts concerning the explanatory power of metaphor-centered accounts of embodiment for higher-level cognition.