>Laboratory rodents placed on a CR diet tend to exhibit increased activity levels (particularly when provided with exercise equipment) at feeding time. Monkeys undergoing CR also appear more restless immediately before and after meals.[62] Despite this brief daily period of increased activity overall activity is no higher in CR than AL animals in youth after an initial period of adaptation to the diet.[63] On the other hand, CR has been found to retard the decline in activity that occurs during normal aging: in one study, animals on a conventional diet "showed little activity" by early middle age, while those on CR "were observed to run around the cage and climb onto and hang from the wire cage tops throughout their life spans. In fact, the longest surviving [CR] mouse was observed hanging from the top of his cage only 3 days before he became moribund."