Lactic Threshold Training, Anaerobic Exercise & Endurance Sports

by Melinda Burris Willms

This article defines lactic threshold and explains the difference between slow-twitch and fast-twitch muscle fibers and details why the latter are so vital in sports that demand fast action such as sprinting. Exercises are given demonstrating how you can train to strengthen and increase your proportion of these all-important fast-twitch muscle fibers.

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LACTIC THRESHOLD: WHAT IT IS

Your lactic acid threshold refers to the amount of exhaustive exercise you can complete before the

level of lactic acid accumulates in your bloodstream at a more rapid rate than your body can clear it. Your body relies on anaerobic metabolism for the energy needed to allow it to do exercise that requires short, high-intensity moments of activity (such as sprints) that must be completed prior to the lactic acid level in the body reaching threshold level, which is the point where the body can absorb no more lactic acid and it begins to build up.¹ This matters because it directly affects your ability to take in oxygen. Generally, an individual reaches their lactic acid threshold somewhere in the 50-80% range of their maximal oxygen uptake (the maximum quantity of oxygen the individual can take in while performing high-intensity exercise). Maximal oxygen uptake is measured as VO2 max.²

When you reach your lactic acid threshold, your body reacts by decreasing the amount of pH in your system. This decline in pH is believed to be the origin of the exhaustion and significant drop in muscle contraction power that occurs as lactic acid levels rise. These negative effects cause the individual to slow down or stop performing altogether. Athletes train to increase their lactic acid threshold in an effort to prolong their capacity to perform high-intensity exercise for longer periods of time.¹

SLOW-TWITCH VERSUS FAST-TWITCH MUSCLE FIBERS

It is important to understand that muscles fall into one of two categories, either slow-twitch or fast-twitch fibers. Athletes who participate in long distance sports rely on slow-twitch muscle fibers which enable them to perform over an extended period of time. High-intensity endurance sports like track depend on fast-twitch fibers to complete high-speed muscle contractions such as those required in sprinting. These fast-twitch fibers allow the individual to perform powerful muscle contractions, but only for a short period of time because fatigue sets in quickly because these fibers are dependent on anaerobic metabolism, which utilizes stored glucose as an energy source. Glucose is exhausted rapidly, which increases lactic acid levels and triggers a burning sensation which interrupts athletic performance.³

SCIENTIFIC STUDY OFFERS PROOF TARGETED TRAINING STRENGTHENS & MAY INCREASE FAST-TWITCH MUSCLE FIBER PERCENTAGE

A scientific study conducted by Jansson et al. and reported in the November 1990 issue of Acta Physiologica Scandinavica followed fifteen volunteer participants, all physical education students and all male subjects who worked out using a Wingate bicycle ergometer with mechanized brakes for a period of four to six weeks, on a schedule of two to three days each week.⁴ The Wingate Anaerobic test first emerged as a popular method of assessing individual anerobic power levels and anerobic capacity (the ability to complete exercise without oxygen) after being initiated at Israel’s Wingate Institute in the 1970s. A basic Wingate Anaerobic test can be done with just two tools: 1)a stopwatch and 2)a cycle ergometer. The test has grown in popularity over the decades due to its simplicity of use and its ability to easily ascertain both anaerobic capacity and aerobic power production—key elements required for successful competition in endurance sports.⁵

In the experiment conducted by Jansson et al., study subjects were required to complete a repetitious series of 30 second sprints at highest possible speeds on the Wingate bicycle ergometer, with 15-20-minute rest breaks taken between the successive sprints. For comparisons, biopsies of the participants’ thigh muscles were performed prior to and following the training sessions for analyzation utilizing myofibrillar ATPase stain to ascertain the proportion of slow-twitch fibers versus fast-twitch fibers—the ones necessary for completing high-speed, anaerobic exercise. The study findings suggest high-intensity training can successfully transform slow-twitch fibers to fast-twitch fibers, effectively increasing an athlete’s ability to perform anerobic or high endurance exercise.⁴

EXERCISES TO INCREASE YOUR FAST-TWITCH MUSCLE RATIO

      The following are exercises you can do to increase your fast-twitch muscle ratio:

1. FRONT POWER STEPUPS: Stand with a box in front of you with your feet shoulder-width apart and your toes pointed. Your chest should be lifted, and your chin should be tucked in. While contracting your glutes, put one foot on the top of the box, and then use that foot to push yourself into the air, then land gently on your other foot on top of the box. Then repeat the contraction of the glute muscles and push yourself into the air using that opposite foot. Continue this movement, alternating legs each time you go up into the air and land.⁶
2. 180 JUMP SQUATS: Be sure to maintain your gaze looking forward. Drop your hips below the knees, jump, extend 180 degrees, reverse and repeat x 3.⁷

WHAT TO EAT BEFORE AND AFTER FAST-TWITCH TRAINING WORKOUTS

 

Because this type of anaerobic exercise depends on glucose for energy, it is important to eat properly before and after your workout sessions. It is best to eat a blend of simple and complex carbohydrates prior to your workout. Examples of complex carbohydrates include:

• Brown rice
• Oatmeal
• Grapefruit

Examples of simple carbohydrates include:

• Milk
• Dark chocolate

*It is best to drink water with your pre-workout meal.⁸

A combination of carbohydrates and protein is recommended post-workout to help repair the muscles and restore energy supply. It is best to eat within 30-45 minutes post-workout whenever possible.

Examples of good post-workout carbohydrates include:

• Chocolate milk
• Rice cakes
• Bananas

Examples of good post-workout proteins include:

• Protein powder
• Protein bar
• Greek yogurt⁹

*Be sure to drink adequate amounts of water post-workout to avoid dehydration.

 

References

1. Quinn, E. (2019, July 30). Lactate Threshold Training for Athletes.
2. Quinn, E. (2019, July 27). VO2 Max Testing in Athletes.
3. Haley, A. How to Improve Quickness. (2010, October 19).
4. Jansson, E., et al. Increase in the Proportion of Fast-twitch Muscle Fibers by Sprint Training in Males. (1990, November).
5. Walker, O. Wingate Anaerobic Test. (2016, January 27).
6. National Academy of Sports Medicine. (2019). How Do I Perform Front Power Step Ups?
7. KGS Academy. 180 Jump Squats. (2012, October 5).
8. Styles, S. The Best Foods for a Pre-Workout Meal. (2018, December 27).
9. Semeco, A. Post-workout Nutrition: What to Eat After Workout. (2016, September 20).

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