Energy Expenditure During Exercise

Our blog today looks at the amount of energy expended during different modes of exercise. As every personal trainer will know, not all modes of exercise burn the same amount of calories and clients should always talk to their fitness instructor about the best way to bring about the results they want to achieve.

While fitness professionals may devise exercise programmes for a range of goals, including training for strength, for many clients the key aim is to improve their cardiorespiratory fitness.

The reason for this is to:

• Improve all-round health and fitness
• Change body composition, reduce body fat and tone up
• Reduce the risk of disease

The ACSM (American College of Sports Medicine) website states:

“It’s important to select a mode of exercise that uses the large muscles of the body in a continuous, rhythmical fashion, and that is relatively easy to maintain at a consistent intensity.”

DIFFERENT MODES WITHIN AEROBIC EXERCISE

The ACSM divides aerobic exercise modes into three groups, depending on the amount of skill demanded by each exercise type.

Group 1 – this covers general exercise that uses the larger muscle groups and for which the energy used is not reliant on the skill of the person carrying out the activity.

Examples: walking, cycling, jogging, climbing stairs.

Group 2 – the energy burned during these activities increases depending on the technical ability and agility of the individual, as their skill allows them to work longer and harder.

Examples: aerobics, step, hiking, swimming.

Group 3 – for these activities there can be a wide variation in the energy expended as those new to the sport will not be able to match the performance of those who are more skilled and experienced.

Examples: football, tennis, squash volleyball.

WHICH EXERCISE MODE TO CHOOSE?

When advising a client on which exercise modes to follow, a personal trainer should not restrict their advice to energy expenditure. Other relevant factors include considering the client’s:

• Overall fitness goals
• Current fitness levels and injuries
• Time available
• Equipment available
• Personal interest in specific activities or sports

Ideally these should be addressed within the screening process, when a client first visits a gym. A personal fitness instructor should be looking at all of these options and addressing any issues.

For example, if a client dislikes a particular activity, it could simply be avoided as they are going to be less motivated if set this exercise. Alternatively, the fitness professional could investigate the reasons behind this dislike – for example, if they were previously pushed to work at an intensity that was too high for them – and adapt the exercise accordingly.

INTENSITY AND INTERVAL TRAINING

As discussed within our blog: Personal training – The FITT Principle, varying the intensity of an activity is a good way for a fitness instructor to help their client make gains.

Simple ways to increase intensity include:

• Adjusting the incline on a treadmill
• Increasing the pedalling resistance when cycling
• Adding another riser to a step

Another option for increasing energy use is to use interval training (see our blogs on Interval training to motivate a client and progress fitness and How a personal trainer can use interval training), during which high intensity training is interspersed with low intensity intervals.

UPPER AND LOWER BODY EXERCISE MODES

As the ACSM website points out, although exercise modalities involving both the upper and lower body will engage a large number of muscles, for example using a cross trainer or rower, they generally would not expend as much energy as running at the same intensity as they don’t engage the same muscle mass. However, low-impact activities such as swimming can be carried out for a longer period of time, increasing the energy expenditure.

WALKING, RUNNING AND CYCLING

Weight bearing exercise, such as running, will normally require more energy than non-weight bearing activities, such as cycling – and the added benefit is that they will help to build bone density, warding off osteoporosis. However, as with swimming, cycling can usually be carried out for a longer period of time to increase the amount of calories burned.

As running is more intensive than walking, it will expend more energy over the same period of time; however, there is a higher risk of injury, in particular to the feet, legs and back.

CONCLUSION

Every client should be approached depending on their goals and current fitness levels and ability, taking into account that someone may be proficient at one mode of exercise but a novice in another. Once a client has mastered a particular exercise mode, the personal trainer can work with them to increase the intensity, get more out of the work out and expend more energy.

With a wide range of exercise modes to choose from, each offering different energy expenditure and benefits, many fitness professionals will prefer to set a varied programme for their clients, with regular changes to intensity and mode in order to help them progress and achieve their exercise goals.