I use monkey type for sprints, see the max I can output in 15sec, 30sec, 1 minute. I improved my speed from 105 --> 130 primarily using 10fastfingers.com I find typeracer to be the most superb site as it includes punctuation and is actual real life passages. You can also compete with other people which is very useful. I find sites like monkeytype better for benchmarking speed than learning to type.