How Different Fuels Play A Role In Training and Performance
If you go to a gas station, you get to choose what kind of fuel your car runs on. You typically have 3 choices of octane fuel.
An example of someone using ATP as their main fuel supply for their activity or sport would be a 100m or 200m sprinter. Another example is an Olympic Power Lifter. These people perform at maximum capacity but are only able to attain this level of exertion due to the quick depletion of ATP and a very rapid build up of waste product or lactic acid.
An example of someone using the "mid-octane fuel" would be a middle distance runner such as a 800m to a 10K runner. Often, this fuel source can be available up to 1 - 1 1/2 hours of medium high physical exertion (i.e. exercising or working at 70 - 85% of maximum exertion).
An example of someone using the "low octane fuel" would be someone running a marathon or cycling for a long period of time.
Fuel expenditures will vary from person to person. The body can also be trained to a certain extent to utilize various fuel sources. But, given our genetic makeup, not all of us can be elite class athletes no matter how hard you try or what supplements you take. The genetic makeup in our bodies are key to how each of us perform individually.
But Hold On Just A Second!! What About Oxygen?
Oxygen is key to "Converting" these fuel sources into useable ATP. This is done during the Kreb's cycle. Ask any high school or college student taking biology based classes about the Kreb's cycle and they'll tell you all about it! Yes, the more oxygen that is available, then there's more potential for creating useable ATP for muscle contraction.
Then There Is The Muscle Fiber Type
Most likely you've heard the terms "fast twitch", "slow twitch", and then a combination of "fast & slow twitch" muscle fibers. These muscle fibers are then classified even further into sub-categories that have various combinations of fast and slow twitch muscle fibers.
A fast twitch muscle fiber typically uses ATP for fuel and is heavily innervated with motor nerves (e.g.. an olympic lifter or sprinter)
A slow twitch muscle fiber uses fat stores or adipose tissue for fuel. Typically, the slow twitch muscle fiber has less motor nerve innervation (e.g. a long distance swimmer or runner).
And finally, the combination of fast & slow twitch muscle fiber. This muscle fiber has a mixed amount of motor nerve innervation. Meaning, it doesn't have as much motor nerve innervation as the fast twitch but it also doesn't have as few motor nerves as a slow twitch muscle fiber (e.g. a middle distance runner or swimmer)
- The type of muscle or motor
- The nervous system or spark plug that innervates the muscle
- The various fuels:
- ATP (adenosine triphosphate)
- Glucose in the muscle cell and circulating blood
- Glycogen stored in the liver which then gets converted to glucose and then is available in the circulating blood
- The break down of fat stores which is then used for available fuel in the blood
We Can Now Define "Strength", "Power", & "Endurance"
Not to draw this out, and relying on the information given previously in this post, a person who is:
"Strength" or when considering when someone is strong is when this person has heavily innervated muscle fibers of which allows a very large recruitment of muscle while performing work against a maximum amount of resistance for a very short period of time or for just one movement. This would be like shot putting, javelin throwing, Olympic lifting, etc.
"Power" is when someone is able to perform a maximum amount of work over a specific period of time. Someone that would be considered powerful would be a elite cycling time trialist. This person has a specific amount of distance to cover in the least amount of time. Maybe a better analogy would be a drag racer. These cars have to be extremely powerful in order to be the fastest in a 1/4 mile run. Savvy?
Here's a little trivia again. Many people are familiar with "Olympic Power Lifting". To me this is an oxymoronic term. It should be just "Olympic Lifting" or "Olympic Strength Lifting" or something along those lines. The athlete is performing work against a maximum amount of resistance for just one lift. This is for the most part the definition of strength.
"Endurance"is simply the ability to endure or last. No matter the work load or resistance, eventually a person or the part of a machine will wear out given the work being performed over time. An elite marathon runner is performing an endurance sport. But because this person has trained for this and has developed a specific skill to complete the marathon in a much faster time than your average joe, they are still enduring a given workload over a period of time. Yes, a marathon runner could be considered powerful, but given the work done over time, this person has more endurance than power. Other examples would be Olympic distance triathlons, open water swimming competitions, basketball players, boxers, soccer players, etc. A lot of work is being performed over a long period of time.
I hope this post gives you a better understanding of strength, power, and endurance. If so, you are now better informed and will be able to plan your workouts and acquire your goals with greater ease and less confusion with just how you should be training.
As usual, feel free to email me for any questions or advice!
Good Health To All,
Brad Senska, PT, DPT, BS, ASTYM.
bradsenska@yahoo.com