Does Weight Training Change Metabolism?

1
Does Weight Training Change Metabolism?
2
Alter Metabolism?

• Many people believe that since muscle burns more
  calories than fat, building muscle by weight
  lifting will noticeably increase the bodys
  metabolism.
• This response is greatly exaggerated.

3
Metabolism

• Weight lifting has virtually no effect on resting
  metabolism.
• Any added muscle is minuscule compared with the
  total amount of skeletal muscle in the body.
• And, muscle actually has a very low metabolic
  rate when it is at rest, which is most of the
  time.

4
Metabolism

• Skeletal muscle burns about 13 kcals per kg of
  body mass over 24 hours when a person is at rest.
• A typical man with a mass of 70 kg (154 lbs), has
  about 28 kgs of skeletal muscle.

5
Metabolism

• His muscles, when at rest, burn about 22 of the
  calories his body uses.
• The brain and the liver use about the same number
  of calories.

6
Metabolism

• If the man lifts weights and gains 2 kg (4.4 lbs)
  of muscle, his metabolic rate would increase by
  24 kcals per day.
• The average amount of muscle that men gain after
  lifting weights for 12 weeks is 2 kg.
• Women will gain less.

7
Alter Metabolism?

• Years of weight lifting and substantial increases
  in muscle mass will increase your metabolic rate.
  
• More muscular people burn more calories, even at
  rest.
• In the short-term (6 months to a year), it will
  not have an effect on most people just because
  you cannot add enough muscle mass to make a
  change.

8
What About Weight Gain?

• A corollary to this hypothesis is that by adding
  muscle you can noticeably change you body weight.
• The idea is that when you do resistance training
  you may actually be thinner yet weigh the same or
  a little more, because muscle is heavier than fat.

9
Body Weight

• That holds a grain of truth, because muscle is
  more dense than fat.
• The problem is that few people put on enough
  muscle in proportion to their total body mass to
  make a noticeable difference in their weight.

10
Body Weight

• The weight gain seen during the initial stages of
  weight lifting is not caused by increased muscle
  mass
• As you train anaerobically, you increase muscle
  glycogen stores.

11
Body Weight

• As you store more muscle glycogen, you store more
  water.
• Water is heavy
• Your weight goes up because you are storing more
  water

12
Body Composition Questions

• For every gram of CHO, 3 grams of H20 are stored
  in the body.
• When glycogen stores are depleted, the loss of
  water leads to a dramatic weight loss because
  each liter of water weighs approximately 2 lbs.

13
Body Weight

• The idea that you will weigh the same or more,
  but you really are thinner may be true if you
  work hard at weight lifting for many months to
  years, otherwise, it is another myth.