The science is in about weight training. Low weight, high reps and heavy weight, low reps are just as good, provided you can tire out the muscles being worked out in 90 seconds. That’s just a minute and a half. Really low weight and lots of reps over a long period of time is just spinning your wheels. Check out this video, it’s excellent, and ACEFitness.Org is a great resource you should have in your Otagenki arsenal.