Energy Systems in a 500m Dragon Boat Race

The typical 500m race is just over 2 minutes in duration, and therefore is categorized as a middle-distance akin to the 800m in track, the hardest to train for! The energy systems used are as follows: ATP-PCr (Phosphocreatine) provides short bursts of high intensity energy output, but stored ATP is depleted after the first 10-15 seconds of the race start. The anaerobic glycolytic system provides roughly half the energy of ATP-PCr, but lasts longer. Anaerobic glycolysis (which creates lactic acid, but does not use oxygen) begins to ramp up after the first 10 seconds and by 30 seconds accounts for the majority of energy production. This can be regulated to last up to 3 minutes, based on intensity, but typically by about 45 seconds the energy output comes from slow glycolysis or the oxidative system (1). For the middle portion of the race we are relying on the glycolytic and oxidative systems, allowing our muscles to recover enough ATP for a final sprint. In a typical 800m race, (with similar times to the 500m in a Dragon Boat) women averaged 33% energy from anaerobic (ATP-PCr and anaerobic glycolysis) with 67% of their energy coming from the aerobic oxidative system, men averaged 39% and 61% respectively(3).

At about 10 seconds as the ATP is used up, there is a decrease in energy output. There is a second decrease in energy output at the 45 second mark as the glycolytic system slows down and the the oxidative system begins to take over. In reality all three systems are in use all the time, but one or two will dominate. Research shows that each of these systems is trainable(2), with the ATP-PCr and glycolytic systems proving adaptable up to 20%, while the oxidative system shows adaptability up to 50%.

Example interval pieces for each energy system

• Type 1
  • Training the ATP-PCr system means working at maximum output for very short times, with long periods of rest in between. Maximum intensity work for 10 – 20 seconds with 1 – 1.5 minutes between. Work to rest ratio from 1:3 to 1:6
• Type 2
  • Training for fast glycolytic increases involves training the body’s lactic acid transport and dissolution which comes from shorter term higher intensity intervals 30 – 45 seconds with similar time for active rest. Work to rest ratio 1:1
• Type 3
  • The oxidative system is measured by VO2 max. Vo2 max increases come from longer term intervals with shorter recovery cycles (i.e. 2-3 minutes at intensity, 1-1.5 minutes active rest) Work to rest ratio 2:1

How should you split your interval training up between these for best results?

The oxidative system proves it’s merits over and over. First, it accounts for the majority of energy production during a typical 500m race (61% – 69%) and second, it responds the best to conditioning! But focusing only on aerobic intervals without adding training for the anaerobic systems would be a mistake as well since over a third of the energy used during a 500m comes from these systems.

Therefore… a case for mixed intervals

Create training plans with 80% mixed aerobic, 20% mixed anaerobic- work. For example, (notation below is x' denotes x minutes, x" denotes x seconds, with x() meaning x times the following set, % is % effort)

• (5' 50%) each side (10 min aerobic warm up)I
• 4(30:30) each side (30 power: 30 active rest) (8 min, 4' anaerobic) Type 2 Interval
• 2(2' 80%, 1' 50% active rest) each side (12 min, ~4' anaerobic) Type 3 Interval
• 6(20" 100%, 1' stopped) each side (16 min, 4' anaerobic) Type 1 Interval
• (2' 65%, 5' 50%) each side (14 min aerobic cool down)

In practice it will be difficult to get this workout completed within 60 minutes, but it’s a great to start!

1. McArdle WD, Katch FI and Katch VL. (2000) Essentials of Exercise Physiology: 2nd Edition
2. Stager Jm and Tanner DA. (2005) Swimming: 2nd Edition; An International Olympic Committee Publication. Oxford UK: Blackwell Scinece Ltd
3. David W. Hill, Journal of Sports Sciences, Volume 17, Issue 6 June 1999 , pages 477 – 483

Read the rest of this post »

Special Phase Strength Training

Read the rest of this post »