If at all possible leave the bread out completely and substitute with a sweet potato or brown rice which are much lower on the GI (glycemic index). Bread is refined or processed (whole grain has more nutrients but is still refined). Anything that is bleached or processed has its chemical structure changed and it breaks down to sugar quicker, therefore it has a higher glycemic index. High GI carbs create a greater insulin spike whereas a low GI food will keep a steadier flow. You can still use dextrose or maltodextrin immediately after training (along with a quality protein) as the insulin spike will help drive protein and nutrients into the muscles, replace glycogen stores and switch the body from a catabolic state (muscle wasting) to an anabolic state (muscle building or sparing)