Hadyn Luke posted this on Monday 6th of August 2012 Hadyn Luke 06/08/2012



In our fitness blog this week we are looking at the various options that interval training offers personal trainers to motivate their clients.

When working with a deconditioned client, fitness instructors will often use interval training as it allows clients to see gradual but steady improvements, which they will find motivating and rewarding. 

If a personal trainer has a client who is used to walking at 6km (working at 60-65% of their heart rate reserve) on a treadmill for 30 minutes, they will be working at moderate intensity. However, simply increasing this speed incrementally is not the most motivating way to progress a client’s fitness.

An example of interval training would be if the fitness instructor dropped the speed to 5km/hr for four minutes, then increased it to 8km/hr for one minute. This would then be repeated through the 30-minute workout, making an average speed of 5.6km an hour.

(5km x 4 minutes) + (8km x 1 minute) = 28km

6 sessions of 5 minutes in 30 minutes

6 x 28km = 168 ÷ 30 minutes = 5.6km an hour 

Although this is lower than the client’s previous speed, because it’s a varied programme, it will increase the stimulus and provide a more comprehensive test of the client’s system.

Using a ratio of four to one allows the client plenty of time to fully recover between the faster segments of the exercise. It also accustoms the client to the idea that they are capable of performing at 8km an hour, when previously they kept to 6km.

Depending on how frequently the client is attending the gym and how quickly they respond to the stimulus, the personal trainer can decide when to change the ratio. If they are training regularly, they may be ready to progress after a week or two.

At this point, the programme can be changed to 5km an hour for three minutes (instead of four), again followed by one minute at 8km an hour. Reducing the rest period by a minute will increase the intensity and the average pace. This means that in only a few weeks, a client can improve their fitness levels and their ability to perform.

(5km x 3 minutes) + (8km x 1 minute) = 23km

8 sessions of 4 minutes in 32 minutes

8 x 23km = 184 ÷ 32 minutes = 5.75km/hr

The next step would be to reduce the rest period to two minutes, so two minutes at 5km/hr followed by one minute at 8km/hr, which would be an average of 6km an hour over 30 minutes. Reducing the rest period further to one minute at 5km followed by one minute at 8km would make the average 6.5km an hour over 30 minutes.

At this point the personal trainer should remind the client how far they’ve come from needing a four-minute rest after a one-minute intensive period to only needing a one-minute rest.

An alternative interval training programme would be to keep the ratio at, say 2:1 but increase the number of minutes, so instead of two minutes at 5km and one minute at 8km, the client could be asked to carry out four minutes at 5km and two minutes at 8km. Equally, the personal trainer could increase the workout intensity by keeping the speed at a steady 6km an hour but gradually increasing the incline of the treadmill. This can be useful for clients who are not familiar or comfortable with high-impact training and prefer to walk on the treadmill but want to work a little harder.

Once the client is comfortable with the 1:1 ratio of intensity and rest period, the personal trainer might return to a ratio of 4:1, keep the rest period at 5km an hour but increase the one-minute intensive burst from 8km to 9km an hour. Again, over time the ratios could be altered until the client is comfortably working at a 1:1 ratio.

Alternatively, the speed of the rest period could be increased from 5km an hour to 6km an hour and the intensive minute could be kept at 8km an hour.

The key is for the fitness instructor to assess their client over the weeks and months that they are training and adapt the most suitable programme variable for each individual.