Weight loss, it turns out, is less a destination than a doorway — one that closes quickly if left unattended. A study following 221 women through structured dieting and exercise found that the cardiovascular and metabolic gains achieved through weight loss largely retreated as pounds returned over the following year. Yet those who had practiced resistance training held onto meaningful protection against diabetes risk, even as the scale climbed back, suggesting that the habits built during weight loss may outlast the weight loss itself.