Sunday, July 31, 2016

On Interval training

It is 5 weeks since embarking on a 16 weeks structured training for the Sriram Properties Bangalore Marathon on 16th October 2016. The only formal training program that I have used the Run Less, Run Faster program from FIRST.  The program is quite intense and controversial in terms of effectiveness - however it has worked for me and helped me progressively improve my FM timings and qualify for Boston in the 2012-13 running season. The program consists of 3 specific runs and 2 days of cross training every week and is also referred to as the 3 Plus 2 program. The 3 specific runs are Intervals, Tempo and the long run. I plan to do a post on each of these 3 runs in that order.

The first training run of the 16 weeks program was a 3 x 1600 m interval run with 400 m rest between intervals which I did at Kanteerva stadium. The last time I had done intervals was in March 2014 - It had  been such a long time that I  forgot the usage of the auto lap feature of  my Garmin 310XT  for tracking the time of the interval. Apart from the fact that it felt great to run on the tracks of the stadium after such a long gap , I was pleasantly surprised to find, when I uploaded my Garmin reading, that I ended up running  6:35,6:43,6:48 versus a target of 7:07(probably due to slow walking between intervals resulting in a fairly high rest interval)!!  Of course, the program recommends not to go all out in the early intervals and to try and maintain a uniform time across all the intervals.

Of the three runs prescribed by the FIRST program the interval training is my least preferred. About 5 years ago when I first started doing them I used to hate and dread them. After a couple of years of consistent training I got over that and felt comfortable but never fell in love with it. And now at the beginning of another such cycle I am thinking is it really important to do intervals? Will the additional effort (and self flagellation) result in much better timing? These thoughts led me to re-read about the benefits of interval training and document them.

Interval training is also variously referred to as speed training and track repeats. This consists of running relatively short distances of between 400 m and 1600 m at a pace typically faster than 5 Km pace on a repeated basis interspersed with brief recovery periods of walking or slow jogging. This helps improve VO2 Max, running economy and speed. As an example run at an intense pace for 1 Km followed by a recovery walk/slow jog for say 2 minutes and then run a hard 1 Km again.  This could be repeated 5 or 6 times. The recovery phase is a really important part of interval training.  The stop-and-start pattern trains the body to recover quickly between bursts of faster running, which, over time, will gradually increase the ability to run faster for longer. This provides a mix of both anaerobic and aerobic training. During the high-intensity phase, the body burns mainly carbs for energy, but during the recovery, it burns mainly fat to produce the energy needed to help it recover from the intense effort.  It is important to establish a good running base before attempting interval training as it would otherwise increase the chances of injury. It is also essential to warm up before and cool down after intervals training for about 10 minutes .

Runners use these terms repetitions and intervals interchangeably, but there is a difference between the two. In both cases you run over a specified distance and the runs are broken up by a recovery jog or walk. The distinction between intervals and repetitions relates to the jog or walkbetween each run and to some extent the length of the run.In an Interval session the time spent jogging / standing rest is kept constant ranging from 2 to 3 minutes — usually too short to allow complete recovery. Therefore a session could be expressed as: 5 x 1000m with 2 minutes recovery (walk or jog)

With a session like this you would have your recovery near the start of the next run so that runners can do their own recovery in preparation for the next run. As the fitness level improves  one would look to reduce the recovery down and maintain the pace until you got the recovery down to 60secs as a minimum.

 The goal for interval training is to “accumulate” time spent running at a very high level and increase the body’s ability to adapt and eventually run at a sustained, higher anaerobic pace for longer periods.

For interval workouts, a general guideline for the amount of recovery time between runs should be equal to or less than the time spent running. For example, if we’re running  800m intervals in  4 minutes, then the recovery time would be 3 minutes. The lower the recovery time the greater the benefit if the interval training if the time goal is met in all the interval repeats.

In the case of track repeats the recovery time is higher so that there is sufficient time for recovery and the interval distance time goal can be hit for each repeat.

This article and its follow up articles give details of the physiology and science behind interval training.

Fartlek which means 'speed play' in Swedish is an unstructured form of interval training. Unlike  interval work, fartlek is unstructured and alternates moderate-to-hard efforts with easy throughout. After a warmup, you play with speed by running at faster efforts for short periods of time (to that tree, to the sign or for a few minutes) followed by easy-effort running to recover.  The goal is to keep it free-flowing so you’re untethered to the watch or a plan, and to run at harder efforts but not a specific pace.

Evolving training plan for AoG

My first run after the Delhi marathon   was  a 10Km on Friday, 8th March - after almost 2 weeks break  from all excercise except walking and...