Every day I finish my scheduled reviews in about 15 mins, then normally i will keep going for another 45 minutes.

Will doing these unscheduled reps help or hurt me in the long term?

More is better I think. I try to add some words too. Always adding lessons from Chinesepod.com but I also work with the HSK vocab. So I am never out of new words and characters that need being memorized.

Doing more reps won't hurt, but I don't think it's the most efficient use of your time. You'll be reviewing things that you'd probably remember the next day/week anyway. I believe it would be better to add more words so that your reviews take longer. Build up slowly though, so you don't get overwhelmed.

If you practice for a long time while adding items, you will automatically get ahead on your reviews while also mixing the new words in (which also gives you more time that session to repeat new ones).

If you practice for a long time without adding, and then add some and practice some more, you're doing a bit more extra reviews, and missing out on the mixing.

If you like extra practice in general, you can adjust upward your target retention rate. Or you can overpractice a bit more automatically by lowering your add word frequency.

The most efficient way in general will be to practice similar amounts of time each day while having enough items for Skritter to add. Unless you know you're going to go on vacation or something, in which case you should turn off adding for a while so you can get ahead on your reviews.

How could it *not* help you? Imagine you normally practice for one minute a day. Then you ask whether practicing for two minutes a day would help. In this case it should be obvious that more practice is better. The same is probably true no matter how long you usually practice per day, although when I get to more than two hours my carpal tunnels start to twinge and my brain starts to fry in my skull.

The only problem would be if the scheduling algorithm is not set up properly and gives you review items too early (as Lyons suggested). I haven't noticed any problems like that.

James