interval training-what ratio of rest to work?

[eire]

Hi,
I'm trying to find out more about effective interval training for cardiovascular fitness training. Is there a specific ratio of rest/relief time to work time that works best?
Thanks for your help.
g

also if anybody knows of any links to sites or references for further info that'd be great.

[archi]

hi,
u can refer to the book by Katck and Katch on exercise physiology which will provide you a little insight into inerval training..

regards
archna

[archi]

u can refer to the book on exercise physiology by Katch and Katch which'll give u an insight into work-rest ratio 4 aerobic and anaerobic training..

regards
archna
sports physiotherapist
india

[physiocrazy]

Hi,
Generally the traning is dependent on the inidvidulal capacity. As a general rule of thumb as the work period is oh high intensity the rest perio is given as double the time. for example if the activity lasts for 1 minute of 95% work out the rest period is 2 minutes.

[physiocrazy]

generally the time of activity is shorter than that as the individual may not be able to sustain the activity for long.

[uranfeman]

Eire,
The length of both the work and rest intervals should be determined by your goals/what (if any) activity you are working for. If you have a specific goal (eg to prepare for sport), then one should perform an activity-analysis to determine what would be the dominant energy systems utilised (ie the ATP-PC, Lactic Acid, or Oxidative system).
By knowing what your development of these systems is compared to what is desirable, one can then manipulate the work and rest intervals (and intensity of each) in order to improve the specificity of your adaptations.

If your goals are for health or fat loss, then we can possibly be a little more lax in our prescription of intervals.

If you want to share your goals I would be happy to give some suggestions, however, some general principles:
- the shorter the rest periods, the more 'aerobic' the session becomes
- the higher the intensity, the higher the EPOC is (possibly leading to greater fat loss).
- the length of the work interval and it's intensity will be inversely proportional

A large number of article on interval training can be found at Peak Performance. Brian Mac's pages offer an easy to understand array of exercise physiology articles, like this one on lactate threshold - an important physiological parameter to enhance for athletes that require cardiorespiratory fitness.

If you have specific questions about manipulating the parameters of an interval session I would be happy to try and answer.

Kevin

[alophysio]

Hi.

For cardiovascular fitness, there has been recent research from the University of NSW in Australia that suggests that 12secs work and 8 secs rest (or vice versa!) for 20mins is an effective regimen. I haven't been able to locate the journal or the reference.

[uranfeman]

yep, I believe it was part of a PhD, where they performed an RCT comparing the influence on fat loss between High Intensity Interval Exercise (HIIE) and Steady State (SS) cardio.
The HIIE performed intervals of 8sec work followed by 12 sec rest for a total of 20mins (that calculates to 60 intervals!), and the SS group built up to 40mins. The HIIE group lost considerably more fat.

This is only one study that is showing that HIIE may be more suitable for fat loss than the SS stuff that we have been told for years (ie the 'fat burning zone'). It should be noted that the participants in the above study were sedentary 20-something women, so you don't have to be fit already to benefit from this form of training (although I'd recommend one be healthy, no susceptibility to musculoskeletal injuries, and under the guidance of a competent fitness professional would be ideal).

For those interested, the abstract and full text of the thesis can be found here.

Of course, its not to say that SS won't work (for some it might be a good starting point). And afterall, a 60x8sec work/12sec rest protocol is just plain HARD, and not everyone wants to commit to that level of difficulty.

Happy Training!
Kevin

[alophysio]

Hi - thanks for that!

Physiologically, the more effort you put into exercise, the more fat you will use. Steady state is advocated because compliance is better compared with a harder programme (as you allude to above).

Too many people get caught up on the fact that you burn a higher % of fat at lower heart rate levels - however 50% of 100Cal is still 50Cal but 20% of 1000Cal is 200Cal!!

Simply put, the harder you work and the longer you can do it, the better the results will be. The hard thing is identifying exactly what the client wants and then what lengths they will go to achieve it.

I recently started training with a client who is a woman. I needed a spotter for my weights and she could do with the advice. I am pushing her harder than she has ever gone before in her weights and she is feeling the benefits. I do it safely of course but so many of our patients simply say they don't know how hard to go so they go easily because it is safer.

I have to spend a lot of time re-educating my clients who have been brain-washed by myths floating around out there...

Thanks!

[uranfeman]

Originally Posted by alophysio

Too many people get caught up on the fact that you burn a higher % of fat at lower heart rate levels - however 50% of 100Cal is still 50Cal but 20% of 1000Cal is 200Cal!!

Yes! I too find people get caught up on the '%Cal from fat' concept that they don't see that they are burning a greater net amount of fat at higher intensities. Who cares if the contribution from fat is 80%, 40% or 10% of the total - as you indicated your total of fat burnt may be higher.

Originally Posted by alophysio

I have to spend a lot of time re-educating my clients who have been brain-washed by myths floating around out there...

Sounds like you're doing a great job of it too. At the moment I'm fortunate to be lecturing in the fitness industry - I think my students are tired of me climbing onto my soapbox about this topic.

[alophysio]

Hi uranfeman,

I don't lecture to fitness people yet but do little seminars every now and then...1 hour talks, really basic - even then, in small groups with hands-on checking and proof of concept (gentle core contraction leads to more power and ability during global tasks), they still do stupid things out on the floor...

I do offer my time though - they pay for a consult to see me and they get one-on-one treatment for their own misguided ideas, i correct their problems and retrain faulty movement patterns and they get CPD for it!!

Good luck - if in sydney sometime, drop by!