In general, people have two main types of muscle fibers in their bodies - Type 1 (slow twitch) and Type 2 (fast twitch).
I'm going to describe the main differences between fast twitch and slow twitch muscle fibers, how you can spot a person with a certain muscle fiber type, what happens to muscle fibers as we age, and how you can enhance your post-workout muscle recovery.
Let's start with slow twitch muscle fibers - also known as Type 1, they have the following main traits:
They have a smaller fiber size
Low force production
Highly fatigue resistant
Slow contractile force
Lots of mitochondria, which are the powerhouses of the cells
Lot of capillaries in and around them to deliver blood for energy
Lots of myoglobin, which is an oxygen storage protein in the muscles
They can maintain longer term contractions - think posture
A person with lots of slow twitch muscle fibers will generally look lean - think of a marathon runner. Lots of lean muscles, made to go on and on without fatiguing.
Fast twitch muscle fibers (type 1) have these traits:
Larger muscle fibers
High force production
Short, powerful contractions
They fatigue rapidly - contractions last for under 10 seconds, typically
Less blood supply in comparison to they type 2 slow twitch fibers
Whereas a person with a majority of fast twitch muscle fibers will have larger muscles - think of how a sprinter looks - they have larger muscles for the very powerful, yet short-lived bursts of strength.
How do fast twitch and slow twitch muscle fibers look?
Well, the best example I can give you is your Thanksgiving turkey!
Slow twitch fibers are the 'dark meat' - due to the rich blood supply and presence of myoglobin, a protein that stores oxygen in the muscle fibers. The 'white meat' is the fast twitch fibers - they're white because of the relatively poor blood supply and less myoglobin!
As we age, we lose fast twitch fibers and gain more slow twitch fibers. Younger sprinters (fast twitch) often set world records at a relatively young age - mid 20's and under. It's rare to see an older sprinter set world records, whereas endurance athletes (slow twitch) peak and set records later in life - mid 30's in many instances!
Regardless of muscle fiber type, they both need adequate nutrients for recovery. Aside from obtaining enough protein in your diet, here are our top 3 nutritional supplements that we use in clinic to optimize natural muscle recovery.
1. Omega-3 fatty acids - work to 'turn on' a specific anabolic (muscle building) pathway in the body - this effect is amplified when omega-3's are consumed with protein
2. Branched Chain Amino Acids - long studied for their role in specific muscle protein synthesis, study after study shows this specific group of proteins can boost muscle protein recovery. Tip - combine with omega-3's for an additive effect!
3. Creatine - good old creatine! Perhaps the most studied nutritional supplement out there, creatine helps re-assemble ATP, the energy currency of our cells. Faster ATP recovery means quicker muscle recovery, repair and protein synthesis.
There you have it - the main differences between fast twitch muscle fibers and slow twitch muscle fibers, and our best muscle recovery nutritionals.