Confused about High or Low Reps?

High Repetitions Burn More Fat- Myth!!!!!

Performing lighter weight with more repetitions (15-20 reps, 20-30 reps, or 20-50 reps) does not burn more fat or tone (simultaneous decrease of fat and increase muscle) better than a heaver weight with moderate repetitions (8-12 reps).

Typically a set’s duration is 20 to 30 seconds. For the average fit person, it requires 20 to 30 minutes of continuous aerobic activity with large muscle groups (e.g. performing Squats) to burn even 50% fat; fat requires oxygen to burn. Performing a few extra repetitions on a weight training exercise is not significant enough to burn extra fat and may in effect burn less fat. If intensity is compromised, less fat may be burned when light weight is used with high repetitions. The ‘burning sensation‘ associated with high repetition training seems to be the primary deterrent for achieving higher intensities.

Higher volume weight training ( 3 sets versus 1 set of each exercise) with short rest periods of approximately 1 minutes can stimulate a greater acute growth hormone release.  It is said that maximal effort is necessary for optimizing exercise induced secretion of growth hormone. So in other words, the more hormones you release the greater your muscle grows.

Intense weight training utilizing multiple large muscles with longer rest between sets may also accentuate body lipid deficit by increasing post training epinephrine, such as performing bench press or deadlifts. Rest periods lasting approximately 4 minutes between maximal exercise exercise of very short duration is required for almost complete creatine phosphate recovery required for repeated maximal bouts. Insufficient recovery may compromise the intensity of the exercise and in turn, possibly decrease intramuscular triacylgycerol utilization following anaerobic exercise with significantly shorter rest periods. Therefore, when lifting heavy weights ensure you have adiquate rest time inbetween your sets.

For individuals attempting to achieve fat loss, the intensity of weight training can be a frustrating ordeal. When beginning an exercise program, muscle mass increases may out pace fat losses, resulting in a small initial weight gain. Significant fat loss requires a certain intensity, duration, and frequency that novice exercisers may not be able to achieve until they develop greater tolerance to exercise. If an exercise and nutrition program is not adequate for significant fat loss, a lighter weight with higher repetitions may be recommended to minimize any bulking effects, although less fat may be utilized hours later. If an aerobic exercise and nutrition program is sufficient enough to lose fat, a moderate repetition range with a progressively heavier weight will accelerate fat loss with a toning effect. If a muscle group ever outpaces fat loss, the slight bulking effect is only temporary. For a toning effect, fat can be lost later when aerobic exercise can be significantly increased or the weight training exercise(s) for that particular muscle can be ceased altogether. The muscle will atrophy to a pre-exercise girth within months. Higher repetitions training may be later implemented and assessed.

Now to confuse you more…. ;)

It still may be recommended to perform high repetitions (e.g. 20-30) for abdominal and oblique training. It has been said muscular endurance may be more beneficial for lower back health than for muscular strength. Furthermore, moderate repetitions with a greater resistance can increase muscular girth under the subcutaneous fat, particularly in men, who have greater potential for muscular hypertrophy. Increasing the thickness around the waist with existing abdominal fat may further increase bulk, particularly in men who typically have greater intra-abdominal and subcutaneous fat in this area. Performing high reps with a lighter resistance should not compromise metabolism or muscle increases, as would performing high reps with light resistance on other, larger muscle groups.

So can you Spot Train???

Contrary to what the infomercials suggest there is no such thing as spot reduction. Fat is lost throughout the body in a pattern dependent upon genetics, hormones, and age. Overall body fat must be reduced to lose fat in any particular area. Although fat is lost or gained throughout the body it seems the first area to get fat, or the last area to become lean, is the midsection (in men and some women, especially after menopause) and hips and thighs (in women and few men). Sit-ups, crunches, leg-hip raises, leg raises, hip adduction, hip abduction, etc. will only exercise the muscles under the fat.

Resources- ACSM’s Resource Manual for Guidelines for Exercise Testing and Prescription