Training for endurance in sport and fitness
Training for endurance in sport and fitness

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

3.1 VO2 max

VO2 max is the maximum volume of oxygen (in millilitres) that the body can use, per kilogram of body weight per minute (ml/kg/min). During endurance exercise the aerobic energy system uses oxygen to convert the body’s fat and glycogen stores into the body’s unit of energy (adenosine triphosphate or ATP). Having the ability to consume and use a large volume of oxygen (VO2) means that a higher level of energy, and thus performance, can be generated. The VO2 that can be utilised by the body is determined by the delivery, extraction and distribution of oxygen to the working muscles (see Table 2).

Table 2 Determinants of VO2 max
Oxygenation of blood Delivery of oxygen Oxygen extraction and use by tissues
Lungs Cardiac output

(stroke volume x heart rate)

Capillary density

(number of capillaries per unit cross-sectional area of muscle)

Transfer to blood Blood volume and flow Mitochondrial density

(number of energy cells)

Haemoglobin content

(O2-carrying capacity of blood)

Stroke volume – the amount of blood pumped out by a single contraction of the heart – is considered the most important factor contributing to VO2 max; elite athletes tend to have higher blood volumes, higher stroke volumes and consequently lower resting and exercising heart rates (Joyner and Coyle, 2008). As well-trained athletes have already improved their oxygen delivery and extraction, large increases in VO2 max are unlikely. Therefore, to further enhance endurance performance, trained athletes may focus on other key determinants such as increasing their lactate threshold or exercise economy.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371