Lactic Acid

Lactic acid is responsible for the burn, right?

For years this has been a common belief of fitness professionals, enthusiasts and exercise scientists. But, latest research has just proven that this belief is a myth. Let’s explain some terms first. Lactic Acid is a liquid produced in muscles during anaerobic training. Anaerobic training is training that you would describe as fairly intense. It is when glycogen (stored carbohydrate) is used as the main energy source for the body rather than oxygen. What about the term lactate threshold? At rest and under steady-state exercise conditions, there is a balance between blood lactate production and blood lactate removal (Brooks 2000). The lactate threshold refers to the intensity of exercise at which there is an abrupt increase in blood lactate levels.

What was thought.
Fitness professionals have traditionally linked lactic acid or ‘the burn’ with an inability to continue an intensive exercise bout at a given intensity. Although the conditions within the exerciser’s muscle cells have shifted towards acidosis, lactate production itself does not directly create the discomfort (acidosis) experienced at higher intensities of exercise.

What is now known.
It is actually something else (the proton (H+) accumulation,) that results in acidosis. It occurs at the same time as lactate production. This acidosis impairs muscle contraction, and leads to the ‘burn’ and associated weariness. Interestingly, the lactate is actually produced to get rid of the ‘burn’ (ie. neutralize’ the exerciser’s muscle acidic environment) (Robergs, Ghiasvand, Parker 2004).

What does this mean for my training?
Lactate threshold is the most important determinant of success in endurance-related activities and events, therefore it’s improvement is the main goal of endurance training programs. By performing lactate threshold training, you are also directly increasing the calories you burn during this type of exercise program. This type of training is also highly recommended to enhance weight loss and weight management.

Research has indicated that training programs that are a combination of high volume, maximal steady-state, and interval workouts have the most pronounced effect on lactate threshold improvement (Roberts & Robergs 1997, Weltman 1995). What does this mean?

High Volume Training
Initially, the best way to improve your lactate threshold levels is to increase your training volume, regardless of the cardiovascular mode of exercise. Increased training volume should be gradual and in the order of approximately 10-20% per week (Bompa 1999). Mix up the total time per session of cardiovascular exercise throughout the week. The minimum bout of cardiovascular exercise should be 10 minutes in duration.

Maximal Steady-State Training
Training at the lactate threshold corresponds to feelings of ‘somewhat hard’ and ‘hard’ (Weltman 1995). Collectively, these sessions should consist of no more than 10% of the total weekly volume (Foran 2001)

Interval Training above the Lactate Threshold
Interval training workouts are high-intensity training sessions performed for short durations of time at intensities above the lactate threshold. To improve endurance, the total interval training workout time should not exceed 10% of weekly training volume. Avoid scheduling the interval training workouts and maximal steady-state exercise sessions in back-to-back workouts.

Why not train like professionals such as Lance Armstrong, and add some Lactate Threshold training into your programme. For further advice, give 6 degrees a call. This article was based on a seminar at Filex 2005 (International Health and Fitness Convention) by Doctor Lenny Kravitz, who interestingly was Richard Simmons exercise scientist in earlier days.