When reflecting upon the glories of springtime, sweat stains do NOT come to mind. The only thing that should be yellow this season are dandelions, not the pits of your T-shirts.
The secret to removing annoying sweat stains -- and all obnoxious stains, for that matter -- turns out to be pre-treating, or soaking or scrubbing the clothing item before putting it in the washing machine. For example, scrubbing grass stains with two parts water and one part white vinegar will lift them from fabric. And letting lemon juice soak into a sweat stain works wonders, too.
Pre-treating also works on condiments, dirt, juice and even ice cream stains. Follow this guide from Samsung for a totally stain-free spring!