When you do a lot of exercise that your muscles aren't used to, they retain water to help them heal. This is how you start to build new muscle. But it can show as a temporary gain on the scale, no loss or smaller loss than usual. Stay hydrated and keep going. We don't always see the results of what we do till next week or later. I've retained water for a couple of weeks, than dropped 5 pounds (seemingly overnight but not really because weight loss is cumulative-what you do over a period of time). Google "why the scale lies" for insight in to water weight. You will lose fat/inches much quicker than people who don't exercise and fit in to smaller sizes faster. I always say I would rather weigh 150 and be a size 4 than weight 140 and be a size 8.