Researchers from Ben-Gurion University have found that the speed that an older adult can execute a voluntary step (especially when distracted by a concurrently performed cognitive task) may serve as a valuable clinical predictor of longevity. The test measures neuromuscular and cognitive vitality.
https://www.bgu.ac.il/en/news-and-articles/dual-task-step-speed-predicts-longevity/
https://karger.com/ger/article/72/5/363/945276/Speed-of-Voluntary-Step-Execution-May-Predict