Wednesday, November 4, 2009

Stolen from Alwyn...The Death of Intervals

Monday, November 02, 2009

The Death of Intervals?

Here's an interview I just did with Mike Roussell:

Mike: Thanks for taking the time to do this interview. First so we all have some perspective, how long have you been a trainer?

Alwyn Cosgrove: I started training people in 1989. Actually 1987 if you count teaching martial arts classes.

In 1995 (after college) I went full time. Since day one I've been very particular (i.e. ANAL ) about what I do. I track and tweak everything. When we opened Results Fitness in 2000, we really started to gather a lot of data. We currently have 250 members and we track all their workouts and body comp changes week in and week out.

Mike: So it is like you run your own fat loss studies at your gym?

Alwyn: Exactly. We had read all the studies showing interval training to be superior for fat loss than steady state training. This confirmed what we were seeing with our clients. But I am a big believer in that there is no physiological limit to the amount of weight a person can lose in a week, month, or year so I kept tweaking and tracking the results.

Mike: What has been one of your biggest breakthroughs lately?

Alwyn: One day it hit me -- cardiovascular programming is an ass-backwards concept.

I don't know when I first thought this - but it was confirmed to me when viewing Lance Armstrong's performance in the New York Marathon.

I'd been taught through my college education and countless training certifications and seminars that cardiovascular exercise was necessary to improve the cardiovascular system and subsequently aerobic performance.

But there seemed an inherent flaw in that argument….

Why didn't Lance Armstrong - with perhaps one of the highest recorded VO2 max levels in history - win the New York Marathon? Or beat people with lesser aerobic levels than himself?

The greatest endurance cyclist (and possibly endurance athlete) of all time - the seven time Tour De France winner - finished 868th and described the event as the “hardest physical thing” he had ever done.

Runner's World Magazine actually examined Lance's physiology (and VO2 max which was tested at 83) and compared them to the numbers of Paul Tergat (the World Record holder and defending NYC Marathon Champion at the time).

They concluded:

"This figure wouldn't mean much if it weren't for the pioneering research of famed running coach Jack Daniels, Ph.D., who first published his Oxygen Power tables in 1979-- According to Daniels, who's rarely off by more than a smidgen or two, a max VO2 of 83 is roughly equivalent to a 2:06 marathon"

Based on his other physical qualities the magazine suggested that Lance was capable of running 2:01:11.

The world record at the time was 2:04:55

Lance ran 2:59:36 (and don't misinterpret me - that's still a great time). But it's clear that the physiology didn't transfer the way the running community expected.

The flaw in this thinking was looking solely at aerobic capacity -- VO2 max - the "engine" as it were. And it's fair to say that Lance had a "Formula One" engine.

But he didn't have the structural development for running. Lance was a cyclist - his body had adapted to the demands of cycling. But NOT to the specific demands of running (in fact Lance had only ran 16 miles at once EVER prior to running the marathon). Lance had developed strength, postural endurance and flexibility in the correct "cycling muscles” - but it didn't transfer to running the way his VO2 max did.

From this example we know that cardio training doesn't transfer well from one activity to another - and it only 'kicks' in because of muscular demand - so why don't we program muscular activity first - in order to create a cardiovascular response. Makes total sense.

So how does this relate to fat loss? We have found that our most successful fat loss programs center around stimulating the muscles to burn more calories - not ramping up and down the cardiovascular system. What matters is total caloric burn and how much you can increase the person's metabolism. It is a total shift in thinking.

Mike: Wow. So it is this the death of intervals and cardio? How to you put this into action with clients?

Alwyn: What we have found is so great about this approach is that you burn more calories, lose more weight, while putting a lot less stress on your joints.

Here's how I like to think about it. Let's look at traditional interval training which uses running.

Depending on stride length - walking a mile takes about 2000 repetitions and running takes 1000-1500 and will burn on average 100 calories or so.

So if we use an interval training model of running and walking - we're looking at around 1500 reps to burn 100 calories.

If we take traditional models of caloric burn - this means we'd need to do 35 miles to lose one pound of fat from our interval training efforts (discounting the metabolic afterburn for now).

So we have a problem. It's a very poor "rate of return" on our "rep investment".

Additionally - running applies a vertical force of 2x bodyweight on the joints of the lower body.

So now we have a dilemma.

Let's choose a 180lb deconditioned overweight client.
1500 reps x 360lbs = 540,000lbs of force to burn 100 calories. (The 360lbs is 2x 180lbs)

That's a LOT of stress on the joints. Literally - TONS!
Now no one was getting injured, but it seemed like there had to be a better way. A better "return"...

So -- we started to think of how we could use different interval training methods other than running to get the same metabolic effect without stressing the joints so much.

We used the airdyne bike, other bikes in order to create a training effect with less load. But whenever you take the bodyweight out of the equation in cardio - you have to work harder to burn the same calories. So this usually needs more reps. So that didn't seem like a much better idea.

At this point we started using metabolic training with weight training implements/kettlebells and bodyweight exercises in the same interval format.

So a circuit of five exercises, performed three times round (15 total sets) would actually burn more calories than the same time spent doing traditional cardio. That was a plus.

But we could also do sets of just 10-15 reps. So we're looking at 225 total reps (with a force LESS than your bodyweight) as opposed to 1500+ reps at double bodyweight.

We gave it a try. Clients loved it (which was a huge plus), and actually started to get better results than we were getting with intervals.

So we get more fat loss, less stress on the body, and happier clients. It is a win-win-win. Currently we don't program traditional interval training our regular fat loss clients anymore.

So, is the death of traditional intervals.

You can get a sample workout using this kind of training program at:

Mike: This is great stuff. Thanks for taking the time. I definitely recommend that everyone go to:

and pick up the workout to try.

posted by Alwyn Cosgrove at 12:04 PM

I'm pretty sure that this is exactly what we do at the studio in our classes :)

What do you think?


  1. Intervals are not dead. This is all well and good if you want to burn fat, but to stress your cardiovascular system intervals are a great way to do that. And for any endurance athlete, intervals are key for sprinting ability during a long hard race. And of course Lance would not have won the NYC marathon he is a cyclist. Being king of one sport doesn't carry over to another.

  2. What Alwyn is trying to say is that this method works best for his FAT LOSS CLIENTS. That is primarily what he and myself deal with on a daily basis. Training athletes such as Marathon runners and Triathletes is a completely different story.


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