What's Your Magic Number?

What's Your Magic Number?

If you're trying to lose weight, here are the pounds that might make you happiest. If you're trying to build muscle, these are the pounds in kilograms.

To find your magic number for weight loss, multiply your starting weight by a decimal value of 1.25 and .05:    For example: A 180 pound person (or 80 kg) would have a magic number of approximately 81 lbs (39 kg).

For building muscle, multiply your bodyweight in pounds by 0.04 for an approximate answer. So if you weigh 200lbs or 100kgs x 0.04 = 1.4+ lbs = 2kgs = 4lbs, you'd need to work up to about 75% of one rep max (1RM) for each set. You can use the calculator below to get your levels:

This is probably the simplest way to determine your magic number for muscle gain. At first glance it seems intuitive that if you lift progressively heavier weights, every set would be approximately equal in terms of its contribution to gains in muscle size or strength. However in reality that's not true at all.

Why? Because two sets of the same weight will never have exactly identical muscle activation levels.

So how do you determine your ideal rep range for mass gains?

I could be wrong, but to me the answer seems simple and obvious. I just want to lift as heavy as possible, and have the best opportunity to give my muscle the biggest bang for its buck.

That's why I lift heavier and heavier weights. What about you?

Purpose: To determine a way to correlate weightlifting rep ranges with gains in muscle size or strength.

Test Subjects: Twelve healthy men, average age 23 years. Muscularity (height/weight/chest) has been measured before each testing session. All trained regularly, but not exclusively on weight training exercises by any means (I didn't want acquired muscle mass defining the results).

Testing Protocol: Steady state training protocol to determine a mean rep range. To achieve steady state, 90% of the body's 1RM is used for exercises involving the major muscle groups (squats, deadlifts, bench presses, etc).

Exercise Used: Overhead press (belts used on Olympic barbells), back squat (barbells used), and medicine ball throws. See below for details:

Overhead press - 3 sets of 10 reps; resting time - between sets varies from 45 secs to 2 minutes depending on intensity.

Back squat - 3 sets of 12 reps; resting time - between sets varies from 45 secs to 2 minutes depending on intensity.

Method of Exercise: The medicine ball is thrown against the upper chest (sternum) or upper back (lumbar). In each case give at least 15 lbs of resistance. After each set, stringently evaluate how hard the muscle was worked; the harder you work a muscle, the more calories it burns.

Results: Muscularity increased after 4 weeks of training. The following tables summarize data obtained from self-reported questionnaires provided by 12 men before and after four weeks' weight training. All weight training was done on 3 non-consecutive days per week.

Strength gains for testing conditions were 10% to 16%, averages about 13%.  As for size gains, the same disproportionate effect was recorded: The overhead presses had a 35% increase in muscle size (an average of 21%). The squats had a 20% increase, an average of 17%. And finally, there was no significant change in hand strength or muscle size with the medicine ball throws.

Calculations: First, I averaged the results and applied that number as a percentage gain to find average strength and muscle mass gain across all subjects. Then I averaged strength changes for each subject with their corresponding changes in muscle mass. Strength increases ranged from 7.8% to 14.9%, average 13.1%, while muscle increases ranged from 10% to 16%, average 12.2%. This suggests that subjects with larger strength gains had larger size gains as well.

Thoughts: The data is convincing, and the methods are sound:

• Weight training helps build muscle, but only for those who are strong enough to lift heavy weights.

• Lifting heavy weights gives you more of an opportunity to stimulate muscle growth (as measured by a greater increase in muscle mass) than lighter weights do .

• The size advantage of heavy training (over light training) isn't as great as the difference in muscle building effects would suggest.

• You can't gain as much muscle with lighter weights, but you can still increase muscle size by lifting heavier weights. You just have to be strong enough to lift that weight and build muscle with it.

What's your opinion? Where do you place yourself on this spectrum?

References: [1] "Heavy Lifting and Weight Training Can Build More Muscle Than Light Training," Mihajlovic, Z., et al. Journal of Strength and Conditioning Research, February 2011, 25(3), 678-685. [2] "Squatting Depth Influences hamstring Activity during a Maximal Squat Exercise," McNair, P., et al. Physical Therapy in Sport, October 2011, 12(5), 175-179. [3] "Muscle Activation and Relative Submaximal Load During Overhead Press," DeRenne, C., et al. Journal of Strength and Conditioning Research, July 2010, 24(7), 1983-1985. [4] "A Review of the Relationship between Bench Press Performance and Muscle Activity in the Prime Movers," Dupuis Benoit and Nicole Roussigne. Journal of Strength and Conditioning Research , July 2008 , 22 (4) , 1373 - 1378 . [5] "Strength Training Impact on Muscle and Strength: Effects, Mechanisms and Practical Applications," Mark D. Beale, 1-6. Journal of Strength and Conditioning Research, August 2012, 26 (8), 2031-2038. : 1-6. [6] " What is the largest muscle group in the body? ," George Brooks . . . interesting questions that stimulate discussion among medical doctors who are interested in exercise physiology. On a related note, here's another from Dr Beach , which goes into some detail about muscle hypertrophy:  http://www.ncbi.nlm.nih.

Conclusion:

The Bottom Line

Healthcare experts agree: If you are serious about losing fat and gaining muscle, it's best to use a variety of rep ranges. However, if you have the luxury of working out only once per week (because you're busy, have limited time or are not willing to do more), then the best method is heavy resistance [1-6]. In other words, it's better to lift heavier weights for less reps than lighter weights for more reps.  This is because it will give you a bigger bang for your buck – that is, a greater effect on strength and muscle size.