Why do interval training sessions?

Interval training sessions or HIT in English ( High Intensity Training ) are essential for progressing in running.

These are interval training sessions with repeated intense efforts. These sessions are rather short but carried out at an intensity level close to our maximum (often at + 90% of our VO2max or our maximum oxygen consumption during full effort).

These sessions allow you to progress because they stimulate a cycle of adaptation of the body by pushing it close to its limits. They are therefore both beneficial and demanding, difficult.

Ideally, you should schedule one or two interval sessions per week in addition to, for example, a low-intensity recovery run and a long run. If you schedule two in the same week, do not schedule them on two consecutive days, but plan at least two days between your two interval sessions (for example, one on Tuesday and the other on Friday).

How to schedule a split session?

To schedule or define a split session, you must take into account the 4 parameters or questions below:

1. Short split or long split?

Short interval training includes repetitions of less than 2 minutes (for example: 30, 60 or 90 seconds) while long interval training will be on repetitions of more than 3 minutes (for example: 4, 5 or 6 minutes). The intensity of the intervals (the speed) of short interval training will be higher than that of long interval training.

2. Number of repetitions?

The goal is to spend about 10 minutes at over 90% of our VO2Max. Depending on the length of the short interval or long interval repetition, this could therefore create interval session options as follows – with a multitude of variations:

• Short interval training - 2 sets of 10 x (30 sec + recovery phase)
• Short interval training - 1 set of 10 x (60 sec + recovery phase)
• Long interval training – 3 repetitions of 4 min + recovery phase
• Long interval – 2 repetitions of 6 min + recovery phase

3. Active recovery or passive recovery?

After each interval, it is important to recover either in passive recovery (stationary with hands on knees) or in active recovery (at a slow pace at less than 50% of MAS for long intervals or a moderate pace at 60-70% of MAS for short intervals). Passive recovery is especially recommended for long interval sessions with short recovery phases (for example, with 4 min repetitions at high intensity with only 2 min of recovery).

4. Duration of the recovery phase between repetitions?

In general, the recovery phase after each high-intensity interval should be at least half the duration of the interval and at most the same duration. To continue and complete the examples of interval sessions above:

• Short interval - 2 sets of 10 x (30 sec + 15 to 30 sec recovery)
• Short interval - 1 set of 10 x (60 sec + 30 to 60 sec recovery)
• Long interval – 3 repetitions of 4 min + 2 to 4 min recovery
• Long interval – 2 repetitions of 6 min + 3 to 6 min recovery

If we now combine the answers to the 4 questions above to program or define an interval training session, we arrive at 4 examples of interval training sessions:

Short split (2 examples)

MEA *	Interval Series	RAC **
10 to 15 min	2x10 x (30 sec @ +90% VMA + 30 sec @ 60% VMA)	10 to 15 min
10 to 15 min	10 x (1 min @ +90% VMA + 1 min @ 60% VMA)	10 to 15 min

*MEA = Action or Warm-up / **RAC = Return to Calm

Long split (2 examples)

MEA *	Interval Series	RAC **
10 to 15 min	3 x (4 min @ 90% VMA + 4 min @ 40% VMA)	10 to 15 min
10 to 15 min	2 x (6 min @ 90% VMA + 6 min @ 40% VMA)	10 to 15 min

*MEA = Action or Warm-up / **RAC = Return to Calm

How to approach interval training sessions?

Here are some additional tips for approaching your interval training sessions:

1. If you are starting a training cycle and you have not done many interval sessions in the previous weeks or months, it is better to allow yourself longer recovery phases without exceeding the duration of the high intensity intervals (30/30 sec or 1 min/1 min etc…).

2. Remember for each interval session to include a progressive 'getting into action' phase of 10 to 15 minutes (don't start off with high intensity intervals) and a progressive 'cool down' phase of 10 to 15 minutes at the end of the session.

3. You can vary the pleasures by doing your interval training sessions on the road, on the treadmill, on the athletics track or uphill.

4. Finally, arm yourself with patience and courage: patience because it will take at least a month of demanding interval training sessions to see the positive effects of these sessions, and courage because these sessions sting!