Ok, you Endurance Athlete…yes, YOU!  I know how much you LOVE your long cardio workouts.  I know how much you LOVE your mileage.  I know how much you LOVE your volume.  I too look forward to my long swims & long runs.

But we’re all getting older.  And that means we absolutely need to shift our focus away from all that enduro training & towards training that targets our fast-twitch muscle fibers.

So why do aging (“aging” = ANYONE over 30 yrs old) athletes need to train their fast-twitch muscles?  Oh my…lots of reasons!  But first, a quick tutorial on muscle fiber types (for a visual, here’s a good video).

Types of Muscle Fibers

Type 1:  Slow Oxidative – These fibers aerobically (i.e., oxygen is used) break down glucose (sugar) into lots & lots of ATP (the muscle’s main energy source).  They contract slowly & are highly resistant to fatigue.

Type 2a:  Fast Oxidative – These fibers are a combo of Type 1 & Type 2.  They use both aerobic & anaerobic (also called “glycolytic”) (i.e. oxygen is not used) means to create ATP.  They contract quite strong & fast & will fatigue more quickly than Type 1.

Type 2b:  Fast Glycolytic – These fibers produce ATP at the slowest rate via anaerobic glycolysis.  As a result, these fibers have the fastest contractions, but also are the quickest to fatigue.

Now that we understand the types of muscle fibers a bit better, let’s move on to why fast-twitch fibers are important…especially for athletes as we age.

Aging & Fast-Twitch Muscles

1. We lose fast-twitch fibers as we age.  When you reach your mid-30’s, IF YOU ARE NOT strength training, you will lose 3-8% of your lean muscle mass every 10 years…and that of course includes fast-twitch fibers.  In fact, research shows that we will lose more fast-twitch than slow-twitch fibers.  While this is a natural aging process, the main reason is this…  Question:  When was the last time you did a workout that targeted your fast-twitch muscles?  If your answer is “More than 1 week ago”…well…if you don’t use them, you will lose them!
2. Less fast-twitch fibers = less power & less speed.  Most athletes I know (myself included) want to be faster & stronger.  We diligently do our long slow workouts…and yes, we do most certainly get faster.  But only to a point.  To move beyond that threshold, we must train & develop our fast-twitch muscle capacity.  Think of it this way:  If you get stronger & are able to produce more power, you can move your body faster.  It’s really that simple!
3. Safety, stability & reaction speed.  What’s the #1 thing that you think of when you think about aging?  For me…it’s slow movements, it’s people who shuffle, it’s folks with compromised balance & an inability to move quickly.  I cringe when I think about what might happen when one of those slower older folks trips on a stair.  They’re going down & most likely injuring themselves.  Without well-trained fast-twitch muscles, you can’t catch yourself, you can’t adjust quickly enough, your reaction speed will be too slow.  You’ll be an injury waiting to happen!
4. Increases in body weight…especially belly fat.  It’s a well-known phenomenon that we tend to gain weight as we age…especially gals in & around menopause.  (Remember that less muscle mass [see #1] = slower metabolism.)  And unfortunately, that weight gain often occurs right around the belly.  Belly fat is particularly unhealthy because it can be comprised of visceral fat which is fat surrounding internal organs.  The awesome thing about training your fast-twitch muscles is that this type of training is AWESOME for burning up belly fat & amping up your metabolism!  So, the best way to fight the muffin top…train those fast-twitch fibers!

So…yep…it’s quite important to maintain your fast-twitch muscles.  I’m sure your next question is “How exactly do I train them?”  Luckily there are multiple ways…each with pros & cons.

Ways to Train Your Fast-Twitch Muscles

1. Speed Work – This is perhaps the most common way that endurance athletes think to train fast-twitch muscles.  Although I will say that when endurance athletes tell me they’ve been doing “speed work”…their definition & mine are often different.  In my book “speed work” truly means short duration (05-15sec) maximal efforts with long rest intervals.  What it is NOT is Tempo work or longer interval training.

Pro:  Direct transfer to actual sport…you’re doing the sport movements only at a very fast rate.  Con:  High level of injury risk if mobility, technique & base aerobic & strength conditioning are not solid.

2. Plyometrics – By now most athletes have heard of plyometric (jumping, hopping, bounding, skipping) exercise.  These types of movements are focused on explosiveness, speed & power.

Pro:  Fun, high intensity movements that can transfer well to actual sport.  Cons:  Again, high level of injury risk.  Careful consideration must be given to which exercises best match the sport(s).  A base level of strength is needed prior to starting a plyo program.

3. Heavy, Fast Strength Training – The goal is to move heavy weights as fast as possible for a small number of reps (usually 1-6).  This is the gym equivalent of sprint training.

Pro:  Usually done with big powerful exercises like Power Cleans, Deadlifts, Squats which work multiple muscle groups.  Cons:  High level of injury risk.  Must have excellent joint mobility & perfect technique.

4. Time Under Tension (TUT) – The exact opposite of #1-3.  TUT lifting uses ultra-slow movements to gradually fatigue Type 1, then Type 2a & finally Type 2b fibers.  By doing so you can train your fast-twitch muscles with significantly less weight & slow, controlled movement patterns.  Key training components of TUT are:

• Shoot for a total lifting time of 01min 30sec to 02min
• Each rep should take around 10-20sec…so roughly 4-6 total reps
• Keep muscles under tension at all times with continuous movement – no stopping at top or bottom of motion
• Speed of lift is constant & continuous – there are no faster or slower parts…just smooth, constant motion
• Lift to full & complete failure (i.e., there is NO way you can keep the motion going)
• Machines are better for this than free weights.  Machines allow you to concentrate only on moving the weight, not the complicated technical aspects of free weights.  And when failure occurs, you want an easy & safe way to get out of the lift.

For more info on TUT training, see my Counterintuitive blog post.

Pro’s:  Very safe, very effective.  If using machines, technique is less of an injury risk issue.  Con:  This is perhaps the most mentally challenging method.  It burns, it hurts, it makes you want to puke!

Over the past year I’ve made it a priority to train my fast-twitch muscles.  Here’s how I integrate it…maybe it’ll give you a few ideas!

• Mon – Swim workout including 8 x 25 yds all-out sprints for 12.5 yds of each 25.  Rest 20-30sec between each 25yd rep.
• Tues – Upper body weight workout (TUT on Incline Bench Press & Reverse Grip Pulldowns).  Finish with 2 x (4 x 10sec) all-out sprints on Air Bike with 20sec rest; 05min rest in between the sets.
• Wed – Rest Day
• Thu – Lower body weight workout in TUT style
• Fri – Swim workout including all-out sprint 25’s or 50’s.  Rest 01min between 25’s or 02min between 50’s.
• Sat-Sun – Low intensity hike, snowshoe, bike…or rest…just depends on how I’m feeling!

So, there you have it!  If you have questions about how to get started with fast-twitch training…or how to adjust what you’re currently doing…or you’d like some new program ideas…let me know!  The key is to just do it.  You can’t afford not too!

Happy training!