[EnderD_503]

Gonna put this in a series of "parts" because not sure that it'll fit all in one post, plus it'll probably just look confusing/chaotic that way. I also noticed there are a few folks around who have weight loss goals, so thought I'd put a bit on weight loss and weight training for them.

The basic premise of weight training as a tool for weight loss revolves around the accumulation of an oxygen debt, particularly through using the ATP-CP (adrenosine triphosphate-creatine phosphate) and glycolytic systems, which do not depend on oxygen as their main source of fuel (but, rather, ATP (body’s energy currency) and glucose respectively). Both of these energy system have a fairly short duration during which they can be used (12 seconds for ATP, 2 consecutive minutes for glycolytic), however, more energy is expended during the use of the ATP-CP system and glycolytic system, than during the use of the Aerobic system (which relies on oxygen). It’s rare that the average gym goer will be using much, if any, of the ATP-CP system (usually used in sports like Olympic lifting, where near 100% of one’s energy is forced into a single explosive movement, or certain positions in American football, rugby and other similar contact sports), however, you could certainly create your workout so that anaerobic glycolysis is used to a greater degree than the aerobic systems. The way one might do this is replacing long bouts of steady paced cardio with 15-20 minutes of interval training (30 second full-out sprints with 1 minute rest then repeat). Or, instead of using light weights for 15-20 repetitions, use challenging weights for 8-10 repetitions or even 5-8 repetitions.

Because the body accumulates this oxygen debt (EPOC/Excess Post-Exercise Oxygen Consumption) while using anaerobic and ATP-CP system (both in weight training utilising these two systems, as well as during interval training and intense, though short bouts of cardio), it must spend more energy/calories in returning to homeostasis after the workout is done. So, for example, you will burn more calories after 15 minutes of sprints/interval training or weight training (working between 70% and >90%) than you would doing an hour of walking/jogging or other forms of cardiovascular activity that depend on oxygen reception and fat burning as fuel, not necessarily during the workout, but after the workout. Some researchers have shown that individuals can continue burning calories in an attempt to recover from an intense anaerobic workout even up to two days later.

On top of the effects of EPOC, during weight training the muscle itself is broken down and requires adequate rest/sleep, proper nutrition, and protein to rebuild itself (therefore expending more calories while existing in the body than fat, which does not require these resources to maintain/rebuild). As the weight training sessions progress you increase the tension in order to coax the muscles into growing stronger, and the stronger they become the more fuel they need/the more calories you burn trying to rebuild. To put it simply: the more muscle you have compared to fat, the more calories you burn just going about your daily life outside the gym/wherever you train.

*Important terms in bold in case anything I wrote wasn't clear and you want to look them up for yourselves.