"Your combo meter is the most important factor for an unarmed-only run. However, the meter's duration time is rather short(only lasts about 2~3 if standing still).

However, you can lengthen the duration time by spamming your unarmed attacks(5 seconds), and even longer if you are hitting an obstacle(+1~2 seconds).

You can move around while doing this... so even though you'll look stupid, you'll still be able to save your high combo meter."