posted May 23, 2012, 3:22 AM by Andrew Jamieson

Physiological Tests

Continuing on from Fitlab Blog 1, I will discuss some physiological tests which can be used to help improve our performance, including: VO2 max, Anaerobic Threshold (also known as AT, LT or OBLA) and blood tests.

These tests (described below) are useful in measuring current performance levels, effectiveness of training, physiological changes, and prescribing accurate training intensities.


VO2max describes the maximum amount of oxygen that an athlete is able to extract from the air. As oxygen utilisation is vital to aerobic performance, VO2max indicates potential for endurance sport. To a greater extent VO2max is genetic, and improvements through training only result in increases of about 15-20%. Because of this VO2max does not need regular assessment, and one test, when an athlete is carrying good conditioning would suffice. Elite male cyclists usually have a maximal oxygen consumption (VO2max) of 70+ml/kg/min and elite females of 55+ml/kg/min. Greg Lemond, in his day, recorded a VO2max of 97ml/kg/min.

Anaerobic Threshold

Anaerobic threshold (also called lactate threshold LT or Onset of Blood Lactate Accumulation OBLA) is the point of greatest lactic acid production in the muscles that is able to be removed. Above this point lactic acid accumulates in the muscles and eventually requires a reduction in pace. TT or race pace tends to be at or slightly above AT. “The ability to produce and maintain a high power output is the single most important physiological factor in determining the success of endurance cyclists”.
To calculate AT an incremental or ramp test is most commonly used (see Fitlab General Assessment). Power output begins at about 90-120 watts and is increased by 25-40 watts every three or four minutes (protocols may vary between labs). The results provide valuable information that can be used to determine training intensities, and monitor the progress, and effectiveness, of a training plan. AT is very sensitive to training and as such should be constantly monitored throughout the season. Professional cyclists have AT power outputs around 4.6 – 4.8 watts/kg.

Blood Tests

As the blood is responsible for transporting oxygen and nutrients, as well as removing waste products, blood tests can provide insights to an athlete’s general well being. Regular tests may help to predict fatigue and overtraining, and show the cause of impaired recovery or reduced performance. Baseline measures in the off season will give a guide to compare future tests with.


Maximum steady state (MSS) is the highest workload (measured in watts and heart rate) that can be maintained over time without an increase in blood lactate levels. After doing an LT test a second test is undertaken at various intensities around LT for nine minutes each workload. For a rider with an LT of 300watts these workloads may be 295,310, 325 watts and so on. Blood lactate is taken every three minutes and a significant rise between any two readings indicates the intensity is above MSS. The results provide valuable feedback for TT and race pacing as well as training intensities. Professional TT specialists can produce over 400watts in long Time trials.

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