Mixing up my front crawl advice please. I swim 2-3 times a week for 30 minutes and do around 50-60 lengths (25m pool, 1250-1500m). I try to just go steady and avoid taking many breaks (at best 1 break, but often more). Should I also try doing shorter 50m sprints with more breaks to mix it up during the week, and perhaps achieve a more varied workout? I swim for the exercise, so the goal is just a good all body workout. Is the above idea worth it versus just doing the slower, continuous swim? Any other variations that are worth giving a go?