Muscle Energetics: Power Output, Part 1

The human body needs energy to fuel three main types of activities: muscular contractions and other cellular movements, the active transport of molecules and ions and the synthesis of macromolecules and other biomolecules.1,5 At the most basic level the source it uses for energy is adenosine triphosphate (ATP).

ATP is the carrier and the immediate donor of free energy in the body. It consists of an adenosine base with three phosphates attached to it. When the bond that attaches one of the phosphates is broken, it releases the energy that fuels the above activities. The problem is that the body doesn't store ATP. In a typical cell it's consumed within a minute of being formed, making the ATP turnover rate very high. Your muscles contain only enough ATP to sustain activity for about a second.5

What happens if you want to exercise for longer than a second? Doesn't just about every type of exercise take longer than a second?

The human body uses a number of energy systems to fuel exercise, and they represent different ways to produce and use ATP. When you're working out, you're also training one or more of those energy systems, and when you take supplements you're trying to enhance one of them. So understanding how the systems work can not only improve your training, but it can also make you a better informed consumer.

The major energy systems include the phosphagen, or immediate, energy system; anaerobic glycolysis; aerobic glycolysis and the oxidative energy system, which is sometimes known as the electron-transport chain. Aerobic glycolysis and the oxidative energy system are used during longer-duration activities and don't apply to weightlifting. This discussion focuses on the phosphagen energy system and anaerobic glycolysis.

How the Immediate-Energy System Works
When you need quick energy for movement, your body breaks down the ATP that's readily available for that purpose by breaking the bond that attaches one of the three phosphates to adenosine. As a result, you get an adenosine molecule with two instead of three phosphates, or adenosine diphosphate (ADP). The equation looks like this:
ATP '> ADP + energy
Remember that there's only enough ATP on hand at any one time to fuel about a second's worth of exercise. If you want to exercise for longer than a second, you have to get more ATP. A substance most bodybuilders are familiar with, creatine phosphate (CP), is used to help you get it.

Creatine phosphate consists of a creatine molecule and a phosphate molecule. When ADP is floating around in your muscles and you need more ATP to keep fueling exercise, the CP donates its phosphate to the ADP to make it.
ADP + CP '> ATP + C
In other words, creatine phosphate helps you resynthesize ATP.
Clearly, the amount of ATP isn't the critical factor. It's such a high-energy compound and is so important to everything in your body that it's probably a good thing you don't have more on hand. The important factor in fueling your workouts is how much CP you have on hand. The more creatine phosphate you have, the longer you can sustain exercise and intensity.

What It's Used For
Depending on which source you consult, the immediate-energy system will fuel exercise for somewhere between six to 10 seconds. It generally fuels extremely high-intensity activities, including the first two to three repetitions of a weight-training set, short sprints, jumps, etc. A number of tests that evaluate this system are very popular with strength and conditioning coaches, such as the one-rep maximum, the vertical jump, the standing broad jump and the 40-yard dash. One-rep maxes test how much weight you can lift one time. They demonstrate how well you can mobilize a particular muscle group to exert maximum force. The 40, vertical jump and standing broad jump all demonstrate how quickly you can do it.

Anyone who needs strength and power needs a well-trained phosphagen energy system. Powerlifters, Olympic lifters, throwers, sprinters, jumpers and football players all come under that heading. So the question is, How do you train to improve it?

Phosphagen Energy Workouts
The point of the training is to enhance the amount of creatine phosphate you have available to resynthesize ATP during high-intensity exercise. There are three main approaches to doing that: weight training, plyometrics and sprints. In terms of weight work, athletes looking for overall strength and power need basic, multijoint exercises performed with a heavy load and a great deal of recovery between sets. For phosphagen-energy-enhancing purposes, you also want to include some quick exercises, such as the Olympic lift variations.

Sample strength and power programs designed to give your energy source a lift appear on the next few pages. Use them as part of a complete periodization mesocycle or just cycle them into your training for a couple of months every so often. The rep numbers refer to rep maximums, meaning the most weight you can lift for the designated number of reps.

As you can see, the workouts consist of basic, multijoint exercises including some variations of the Olympic lifts. The weights are extremely heavy, with a long recovery after each set.

You can also enhance your phosphagen energy system with sprints and plyometrics. The gains from those efforts will be site specific. Sprints that are less than 10 seconds in duration enhance your lower body's ability to store and use creatine phosphate, and you can perform plyometric exercises for the lower body, upper body and even the abominals.

Supplements and the Phosphagen Energy System
With your training program set, the next step is to adjust your supplement schedule to enhance it. The best supplements for jump-starting your immediate-energy system are creatine and ribose. When it comes to creatine, both creatine monohydrate and creatine phosphate are effective.3 Creatine supplementation enhances the levels of CP in your muscles, allowing you to maintain your ATP levels during exercise'so you can exercise harder for a longer period of time.6 Because it works on the phosphagen energy system, creatine supplementation has been found to enhance strength, power and sprint performance.4 Ribose, a sugar, synergizes with creatine to further enhance CP levels.

ALLWhat's the best way to use creatine and ribose supplements? I'm frequently approached by weight trainees who have been loading creatine for two to three years and are not seeing any results from it. Here are some suggestions.

• Loading phase. Take 20 grams per day for five days, specifically, four servings of five grams each.2,4
• Maintenance phase. Cut back to two to three grams per day, taking it only on the days when you train.
• If you're using regular powdered creatine, take it with food. If you're using effervescent creatine, take it about 1 1/2 hours after a meal.
• Minimize your caffeine intake, as it may interfere with creatine absorption.4
• When you're entering your more intense training phases'when you really need creatine'get back on a loading phase.
• Remember to cycle the creatine.
• Don't load for two to three years straight.
• If you want maximum ATP power, in addition to the creatine, take 2.2 grams of ribose before and after training. [Note: AnaVol-R is a new muscle cell volumizing supplement with both. For more go to the Muscle-Link Web site.]

  So why not get on a loading phase and stay on it? Does it have to do with those serious side effects you're hearing rumors about? It's that old adage, More isn't necessarily better. It appears that human muscles will only store a finite amount of creatine. After that they become saturated and won't store any more.2 Most studies of creatine supplementation show that after five days of loading, a person's muscles are saturated with creatine. If you keep loading under those conditions, the extra creatine has to go somewhere, so it gets processed by your liver and kidneys. Theoretically, if you take too much for too long and really overload your liver and kidneys, you can be looking at liver and kidney problems. That's the reason it's important to cycle your creatine intake.

  In Part 2 I'll discuss techniques for enhancing anaerobic glycolysis.

  Strength Program
  Train six days per week. Rest 60 to 120 seconds between sets.
  Days 1 and 4
  Back squats 4-6 x 3-9
  Hack squats 4-6 x 3-9
  Lunges 4-6 x 3-9
  Leg curls 3 x 8-12

  Days 2 and 5
  Push presses 4-6 x 3-9
  Bench presses 4-6 x 3-9
  Close-grip
  bench presses 4-6 x 3-9
  Front raises 3 x 8-12

  Days 3 and 6
  Deadlifts 4-6 x 3-9
  Bent-over rows 4-6 x 3-9
  Barbell shrugs 4-6 x 3-9
  Barbell curls 3 x 8-12

  Power Program
  Train five days per week. Rest 120 seconds between sets.
  Days 1 and 4
  Back squats 5-8 x 1-6
  Power cleans 5-8 x 1-6
  Lunges 4-6 x 3-9
  Stiff-legged deadlifts 4-6 x 3-9

  Days 2 and 5
  Good mornings 5-8 x 1-6
  High pulls or deadlifts 5-8 x 1-6
  Bent-over rows 4-6 x 3-9
  Pullups 4-6 x 3-9

  Day 3
  Push presses 5-8 x 1-6
  Overhead squats 5-8 x 1-6
  Bench presses 4-6 x 3-9
  Parallel-bar dips 4-6 x 3-9

  References

  1 Bessman, S.P., and Carpenter, C.L. (1985). The creatine-creatine phosphate energy shuttle. Annual Reviews of Biochemistry. 54:831-862. 2 Greenhaff, P.L. (1995). Creatine and its application as an ergogenic aid. International Journal of Sports Nutrition. 5(supplement):S100-110. 3 Peters, B.M.; Lantz, C.D.; and Mayhew, J.L. (1999). Effect of oral creatine monohydrate and creatine phosphate supplementation on maximal strength indices, body composition and blood pressure. Journal of Strength and Conditioning Research. 13(1):3-9. 4 Plisk, S.S., and Kreider, R.B. (1999). Creatine controversy? Strength and Conditioning Journal. 21(1):14-23. 5 Stryer, L. Biochemistry, 3rd edition. New York: W.H. Freeman and Company. 1988. 315-320, 935-936. 6 Vandenberghe, K.P.; van Hecke, M.; Leemputte; Vanstapel, F.; and Hespel, P. (1999). Phosphocreatine resynthesis is not affected by creatine loading. Medicine and Science in Sports and Exercise. 31(2):235-242. IM