Edited by: Danielle Abel

Understanding Work to Rest Ratios

Work to rest ratios should be programmed based on an athlete's assessed energy system needs. Their needs will be based on the primary demands of their sport. 

Energy Systems

First, let's go over the energy systems and the associated duration of each

• Phosphagen (aka ATP-PC system) (5-10 seconds) 
• Fast Glycolysis (15-30 seconds)
• Fast Glycolysis/Oxidative (1-3 minutes)
• Oxidative > 3 minutes

Work to Rest Ratios

Next, let's define work to rest ratio - this is the ratio used to determine how long an athlete is working in comparison to how long they should ideally rest in order to restore substrates for energy metabolism for the athlete's primary energy system

• Phosphagen: Work to rest ratio of 1:12 to 1:20
• Fast Glycolysis: Work to rest ratio of 1:3 to 1:5
• Fast Glycolysis/Oxidative: Work to rest ratio of 1:3 to 1:4
• Oxidative: Work to rest ratio of 1:1 to 1:3

Energy Systems in Use

If an athlete is sprinting for 10 seconds, the energy system used would primarily be the phosphagen system, or the ATP-PC system. In this case, adenosine triphosphate (ATP) & phosphocreatine (PC) would primarily be responsible for providing quick energy to the muscle.

If an athlete is sprinting for 30 seconds, for example, a 200-meter sprint, or a soccer player as a mid-fielder, the energy system used would primarily be fast glycolysis, also known as anaerobic glycolysis. Anaerobic glycolysis results in lactate formation. 

If an athlete is running for a half-mile, for example, the energy system used for this would be a combination of energy systems - both fast glycolysis (anaerobic glycolysis) and the oxidative system. In this case, the athlete would be running above the lactate threshold (the level of lactate that is above the resting lactate level in the blood). 

If an athlete is running a mile, a 5k run, etc., the energy system used for this would be the oxidative system. 

Exercises & Work to Rest Ratios by Energy System

• Phosphagen: Box jumps, broad jumps, sprinting

For an 8 second sprint for example, we would want to use the 1:12 to 1:20 work to rest ratio. 

So 8 seconds x 12 = 96 seconds of rest at the minimum. At the maximum, we would take 8 seconds x 20 = 160 seconds of rest. So if you are asked what is the optimal work to rest ratio for an 8 second sprint: 2 minutes, 3 minutes, or 4 minutes? It would be 2 minutes because 120 seconds is between 96 seconds and 160 seconds.

Overall, the ideal rest for the phosphagen system would be 1:30 to 2:30 minutes.

• Fast Glycolysis: 30 second sprint - or a 200 meter sprint on the track

For 8 sets of 200 meter sprints (that take approximately 30 seconds), we would want to use the 1:3 to 1:5 work to rest ratio. 

So 30 seconds x 3 = 90 seconds of rest at the minimum. At the maximum, we would take 30 seconds x 5 = 150 seconds of rest. This would allow the lactate to clear and allow ATP to reform in the muscle cells. 

Overall, the ideal rest for fast glycolysis would be 1:30 to 2:30 minutes.

• Fast Glycolysis/Oxidative: 2 minute swim intervals 

So 2 minutes x 3 = 6 minutes of rest at the minimum. At the maximum, we would take 2 minutes x 4 = 8 minutes of rest. During these 6-8 minutes of rest, low intensity, low effort, oxidative movements could be used (backstroke, a technique drill, etc.)

• Oxidative: 1 mile run, rest, 1 mile run, rest (5 minute mile) 

So 5 minutes x 1 = 5 minutes rest at the minimum. At the maximum, we would take 5 minutes x 3 = 15 minutes of rest. The 5-15 minutes of rest could be used to work on sub-threshold efforts with a slow run or walk for recovery before the higher intensity run would start again. 

Summary

The phosphagen system is going to be efforts lasting less than 10 seconds. The fast glycolysis (anaerobic glycolysis) is going to be efforts lasting less than 30 seconds. A combination of glycolysis & oxidative is going to be efforts lasting less than 3 minutes. Lastly, the oxidative system is going to be efforts lasting greater than 3 minutes in duration. 

Once you know which system your athlete is primarily working in, you can easily apply the proper work to rest ratio. 

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