Given that "Superslow" is long out-of-print and much more research and refinement has occurred since the early 1990's I am hesitant to recommend it to anyone other than hardcore collectors of bodybuilding or exercise related ephemera. Ken Hutchins recently updated the entire Superslow manual and further elaborated on many more topics by publishing "The Renaissance of Exercise: A Vitruvian Adventure Volume I" (2011) which is only available via mail-order and not in retail stores. It doesn't even have an ISBN number inside. But "The Renaissance of Exercise" will give you the majority of chapters from the original SuperSlow technical manual in a much more durable hardcover textbook format. It is 320 pages of no-holds-barred Ken Hutchins simply telling the truth about what he has learned after 35 years spent rigorously studying exercise. Considering current prices of some used copies of "Superslow" for sale here on Amazon you might as well spend the $150 with the folks at RenEx and you'll get _WAY_ more for your money. You can also read some of those chapters/articles for free on the RenEx website or at Hutchins' website called SuperSlow Research Zone.
Your heart rate refers to how many beats per minute (BPM) your heart is pumping, and when it comes to working out, knowing your heart rate can help determine if you’re working at the right intensity. You have your resting heart rate, which is how fast your heart is beating when you’re doing nothing (the best way to measure this is to take your pulse first thing in the morning). Generally speaking, this gets lower as you get more fit because your heart doesn’t have to work as hard to pump out blood (although if you have a naturally low resting heart rate thanks to genetics, it may not get much lower, and that’s totally fine, says Lefkowith). According to the American Heart Association, the average is 60-100 BPM. You also have your maximum heart rate, which is the hardest your heart can work efficiently.

Before beginning any workout program, it’s always a good idea to consult your physician. Individuals with pre-existing injuries or medical conditions or those who don’t have an accurate knowledge of their current physical fitness level should always begin cautiously. It’s also extremely important to perform all workouts, no matter what fitness method you’re doing, under the supervision of a certified instructor. Their guidance and knowledge of proper form and technique will help you to achieve maximum results while avoiding injuries. They can also help you to safely modify workout activities to match your current fitness levels and goals. Whether you attend classes in a studio or at home through DVDs or streamed videos, the presence of a trained instructor is imperative.
It's important to note that you can spread your activity into intervals as short as 10 minutes. So if you have a very busy schedule, even doing three, 10-minute aerobic exercises per day, five days per week, will be sufficient. To get you started, here are the different types of exercise, how they benefit the body and what kind of activities they entail:
Exclusion criteria included major diseases or conditions such as severe heart disease, uncontrolled hypertension, obesity, osteoarticular pathology, and neurological disease. Criteria were evaluated on the basis of clinical history, resting ECG, and physical examination. Participants maintained their lifestyles and were instructed not to take part in any other physical programs throughout the study. At the time of the initial design, the study consisted of a 12-week randomized controlled trial with a frequency of 3 times a week, 36 sessions in all, ending with a new assessment of their wellness and the potential persistence of the results on functional/physical capacities.