V02 Max

Understanding your VO2max or aerobic power is key to maximising your endurance training and performance. So what exactly is your aerobic power and why is it an important factor in athletic training?

VO2max Defined

As exercise intensity increases so does your uptake of oxygen. So for example the faster you run the more oxygen you must consume to sustain the pace. Here's the key...

There comes a point where your body simply cannot increase the amount of oxygen it consumes and utilises, despite an increase in exercise intensity. This is your VO2max...

"the maximum amount of oxygen you can take in and utilize measured in mL.kg.min".

Have a look at the graph below. The horizontal axis represents exercise intensity. The vertical axis represents oxygen uptake. Where the line levels off illustrates a plateau in oxygen uptake despite this particular athlete running faster.

Imagine your VO2max as your "aerobic ceiling". If exercise intensity increases after you have reached your VO2max your body must use predominantly anaerobic (without oxygen) pathways for energy production. The result?

Lactic acid begins to accumulate rapidly. You can only continue exercising at that level for a few minutes at most.

From the graph above the athlete has the potential to exercise predominantly aerobically at an intensity of level 6 or 7. In other words he or she can potentially maintain a level of work for a prolonged period of time.

In reality lactic acid begins to accumulate rapidly before most individuals hit their VO2max. Another variable -- lactate or anaerobic threshold has a large bearing on this.

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VO2max In Elite Athletes

VO2max is a good indicator of aerobic endurance performance in the general population. Untrained individuals with a higher VO2max will tend to perform better in endurance events than people with lower values for aerobic power. Is the same true for top athletes?...

While it's true that elite endurance performers often have ridiculously high values for VO2max compared to us mere mortals, other factors at that level come into play.

The very best athlete won't necessarily have the very highest VO2max. Lactate threshold, locomotion velocity (the speed you are moving when you hit VO2max) and nutritional status are significant issues in elite competition.

Below are some values of VO2max for top athletes. To give you a comparison the average sedentary female has a VO2max of around 38 mL.kg.min and the average male, 42 mL.kg.min...

VO2max Values For Elite Athletes
Sport	Female	Male
Cross country skiers	65	83
Middle distance runners	59	80
Swimmers	56	77
Speed skaters	54	76
Cyclists	56	75
Rowers	42	61
Soccer players	No data	62
Fencers	44	No data
Weight lifters	No data	54

So what factors affect a person's VO2max, and can you improve them?

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Factors Affecting VO2max

There are 6 major factors that affect your aerobic power...

1. Genetics
Genetics is said to play a 20-30% role in VO2max.

2. Your age
After the age of 25 VO2max decreases by 1% a year. The good news is regular physical activity throughout life can offset much of the decline.

3. Training status
Athletic training can alter a person's VO2max as much as 20% depending on their lifestyle and fitness habits.

4. Exercise mode
Measure an athlete's VO2max on a treadmill test, then a cycle test and finally in a swimming pool and the results will all differ significantly. Treadmill running has been shown to produce the highest values.

5. Your gender
Women generally have VO2max values that are 15-30% lower than men's. This takes into account differences in bodyweight. With a straight, like-for-like comparison the difference is even greater.

6. Your body composition
Much of the differences in VO2max between men and women is attributed to body composition. Although there are other biologic differences between the sexes, research suggests VO2max decreases as body fat percent increases.

So can you improve your VO2max?

In a nutshell aerobic power can improve 6-20% with athletic training. However the larger gains usually come from untrained, sedentary individuals. If you are a regular exerciser and particularly if you consider yourself to be an endurance athlete...

Chances are endurance training will only make small improvements in your VO2max. Take heart though...

You can train specifically to improve your lactate threshold. Very few people, even athletes can exercise close to or at their VO2max for prolonged periods...

A competitor may well have a higher VO2max than you but with training you can tap more of your 'aerobic potential' than they do. The net result?

You can maintain a faster pace than them for longer. Another plus point to remember...

Having a high VO2max means nothing if you can't run, swim or cycle very fast when you hit it. Improving your movement economy so that you are running faster for example when you hit your VO2max will definitely improve your endurance performance.

The final step is to measure your VO2max...

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Measuring VO2max

There are 2 types of VO2max testing...

• Direct
  
• Indirect

Direct testing does exactly what its name suggests -- a gas analyser is used to measure gas exchange directly. Indirect testing predicts your VO2max based on your performance in a fitness test...

It's less accurate but provides a practical alternative if you don't have $100,000 worth of equipment and a lab technician handy! See the endurance tests page for tests you can use to estimate VO2max

Both indirect and direct tests can be maximal or submaximal. Simply put a maximal test involves exercising to exhaustion. A submaximal test lasts for a set period of time or distance and is more suitable for individuals who can't exercise all out (i.e. elderly patients).

Knowing your VO2max on its own is useful. But it's far more useful if you know and understand you lactate or anaerobic threshold as well.