this is a good peice of reading
How to do cardio if you MUST!
View all articles by MariAnne Anderson
Written by : MariAnne Anderson print article email article
As we enter into this, the month of the New Year’s resolution, a common question that hits the boards is “how much cardio should I do to lose this gut/ass” (depending on your particular assignment of X and Y chromosomes).
To anyone who knows me, the thought that my lazy, cardio-hating ass would actually sit down and WRITE about this most … unpleasant of activities, bear with me – this profound distaste has fuelled my attempt to find a way to optimize physique goals while doing as little cardio as humanly possible.
In spite of my deeplfy-rooted loathing for this type of activity, I am gradually learning to respect some of the benefits targeted amounts of it can do – not only for fat burning, but also for muscle growth (gasp!). (1) (2)
Although all exercise has a resistance and a cardiovascular component, for this purpose, we shall consider “cardio” to be endurance-types of activities rather than those performed primarily for hypertrophy or strength.
As in all things, there are pros and cons to the different types of cardio. A non-exhaustive list of benefits variously include:
• Increased mitochondrial density and size
• Increased capillary density
• Increased vo2 max
• Increased heart stroke
• Increased endurance
• Faster recovery/reduced DOMS (delayed onset muscle soreness)
• Improved insulin sensitivity
• Improved lipid levels
However, there are downsides:
• Repetitive strain injuries
• Potential for conversion of fast twitch fibres to slow twitch analogues
• Overtraining, particularly of leg muscles
• Unfavourable endocrine changes (reduction in testosterone, increase in cortisol)
• Increased efficiency
• The “Kobe legs” phenomenon of marbled leg fat, particularly problematic in females
• Appetite stimulation that exceeds activity-related expenditure
• And of course, boredom <yawn>
We don’t do the same lifting workouts all the time – why should cardio be any different? And I’m not alone in my thinking: for example, Berardi suggests incorporating volume, intensity and load progressions into your cardio work. (3)
In the text below, I will discuss the pros and cons of three different intensities of cardiovascular training – high intensity interval training, hill-repeats, and steady state (SS) cardio, and a strategy for integrating them into your fitness plan, which, as always, you will find summarized at the end so you don’t have to fall asleep trying to read my article. <blink blink>
HIIT – High Intensity Interval Training
HIIT is a protocol of alternating high and low intensity exercise, for example sprint/walk intervals.
Research has shown a number of physique-enhancing benefits to HIIT:
• “High intensity training may prove beneficial if used properly. For example, its potent stimulation of whole body lipolysis during exercise leads to a rapid influx of plasma free fatty acids after intensity is lowered. In this context, it is postulated that performing a notably short, high intensity session, followed by a long duration, low to moderate intensity workout, may optimize lipid oxidation.” (4)
By following HIIT with a little steady state cardio, you’ll oxidize mobilized FFAs so they don’t re-esterify into triglyceride and hang around. Cool eh?
• In fact, HIIT may actually curtail the propensity for fat storage:
”...it is highly probable that sprinting-evoked, systemic AMPk activation simultaneously curtails an individual's natural genetic propensity for fat-storage as well. This is because, in response to the rapid ATP-depletion prompted by those repeated, maximal-intensity bouts of anaerobic expenditure, AMPk also works to curtail Acyl-coenzyme A: diacylglycerol acyltransferase (DGAT1) activity and glucose uptake into adipocytes.
This saves ATP for energy repletion rather than having it "misallocated" to synthesize new triacylglycerol (TAG) in your adipocytes. (5)
• HIIT has a higher EPOC (excess post-exercise oxygen consumption) than steady state cardio.
• It leads to rapid improvements in VO2max and endurance performance (6) – this means you’ll perform better lifting workouts, too.
• It doesn’t promote the conversion of type IIb (the so-called "pure" fast-twitch muscles) to type IIa slow-twitch analogues (7) (see below, steady-state cardio discussion).
• And it can help increase carbohydrate metabolism, which can improve nutrient partitioning. (8)
HIIT doesn’t “work” by burning off fat – it works by stimulating catecholamines (9), and catecholamines strongly stimulate lipolysis in mammals. Plasma fatty acid concentrations increase dramatically immediately after intense exercise, where fatty-acid oxidation decreases. That’s why you do some steady state cardio at the end.
How often: If you’re going to do any cardio, do HIIT at least once and at most three times a week. Ideally, do it either on its own day, or on a leg day at least 6-8 hours away from your workout.
If you must do it in the same session as your workout, do it right after, on a leg day. Although this may seem counterintuitive, HIIT is quite the leg workout. Doing HIIT on upper body days may compromise recovery since your legs will have less time to rest.
What to eat: Because of the strong anaerobic component, feed HIIT the same as you would a lifting workout – target some carbohydrate and protein to provide an available pool of amino acids and to stimulate the cortisol-blunting insulin response.
For those of us whose diets are lower in carbs, you’ll want a little carb in you pre-workout or you WON’T be able to give these sprints your all, much like a lifting workout. If your carb consumption is ample, just focus on post-HIIT carbs. At least one study showed that post-workout carbs/protein didn't impact FFA burning post-exercise: “in the post-exercise recovery period, muscle glycogen resynthesis has high metabolic priority, resulting in post-exercise lipid combustion despite a high carbohydrate intake”. (10) So your post-workout Nitrean shake with dextrose is fine here.
Sample 20-something minute HIIT workout
I do these on side-by-side treadmills. And yes, it looks ridiculous to see me hopping from one treadmill to the other. (11)
• Three to five minute fast incline walk to warm up (3.5 mph, 3-5% grade works for me)
• Flat-out (but safe!) sprint for 20 seconds (I do these at 10 MPH, flat)
• Return to a fast incline walk for 40-60 seconds.
• Repeat 6-9 times. Try to increase the number of sprints you can do each week.
• Finish with 10-20 minutes of fast incline walking to burn off the free fatty acids mobilized by the intervals.
HIIT Variations
If you’re going to do more than one HIIT workout a week, you could do one with as many as 12 sprints with a 20:40 work:rest ratio, and the other with as many as 8 sprints with a 30:60 work:rest split.
For those new to exercise:
Of course, if you are new to exercise, do NOT jump into HIIT! Ease into it slowly – start with steady state a few times a week, then gradually introduce short periods of modestly increased intensity as you feel able.
For example, instead of sprinting, you could do something as simple as alternating periods of faster and slower walking. While not HIIT, it IS interval training, and will get you used to varying the intensity while you build up your fitness level – particularly if you’re still significantly over fat. As you drop to lower and lower levels of body fat and your conditioning improves, you can increase your “sprint” speed accordingly.
Another option: Tabata
For those of you who find a 20:40 work:recovery interval too leisurely, may I suggest Tabata...
• 20 seconds high intensity work (you should reach failure/exhaustion)
• 10 seconds rest
• 8 sets = 4 (really, really brutal) minutes in total
• You can do it with sprinting on a track (probably the best), sprinting on a bike (also very good), or even with weights (squats, thrusters, chin-ups, push-ups, etc).
Check out
www.cbass.com/FATBURN.HTM for more detailed info.
Stubborn Fat Loss protocol
Toward the end of a cut, when you’ve hit your body fat target (or close) but are left with small, stubborn pockets of subcutaneous fat that will NOT budge, there is a variant of HIIT that may be helpful – the so-called Stubborn Fat Loss protocol (12). I’ll discuss this in an upcoming article (don’t worry, it’s already written) but don’t worry about it for now – after Christmas eats, we’re all FAR too fluffy to benefit from this one JUST yet... <burp!>
Hill Repeats
“Hill training is excellent for improving maximal oxygen uptake because both high heart rate and high systolic pressure (the multiplication of these factors is known as the "rate-pressure product"
are achieved, and these components stimulate left ventricular hypertrophy and vascular development.”
“When doing full-fledged in-season work at VO2max, your aim should be to create a session which can blend in favourably with other sessions and races and which allows you to accumulate enough time to provide a viable stimulus for improvement without overdoing it.
Avoiding overkill basically means minimizing the negative effects of acidosis, so that your movements remain efficient, muscle groups are recruited in harmonious concert, and aerobic energy production dominates your efforts as long as possible. This is best achieved if you orchestrate the rest intervals between bouts so as to allow adequate recovery while also keeping the circulatory system active, thus reducing the possibility of "venous pooling" and allowing for some lactate to be reconverted to other metabolites by the heart and skeletal muscles.” (13)
“Those who run on hills have also been shown to be less likely to lose fitness when they take time off from training. And many scientists believe that hill training can improve the elasticity of muscles, tendons and ligaments, allowing these tissues to carry out more work with less effort and fatigue…Other research, carried out by Dr. Bengt Saltin, discovered that runners who trained on hills have much higher concentrations of aerobic enzymes - the chemicals which allow your muscles to function at high intensity for long periods without fatigue - in their quadriceps muscles than those who did all their running on flat terrain." (14) So, well-conditioned ligamefnts and tendons in leg muscles that are resistant to fatigue – all good things for those of us who do a lot of heavy squats!
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“One of the objectives for longer interval training is to improve the body’s ability to function in the presence of lactate. The higher level of effort raises the body’s energy demand beyond what can be generated through primarily aerobic metabolism, and the anaerobic systems become more important. The body’s aerobic energy systems are much more efficient than the anaerobic systems, but have a limited rate of energy release. Training for endurance sports, such as marathons or triathlons, focus on developing the body’s cardiovascular system to increase its aerobic capacity, and also on increasing the lactate threshold, which allows sustained physical effort at a higher, partially anaerobic level.
During incline or pace intervals, you’re moving the body’s energy production in and out of mostly aerobic and mostly anaerobic modes” (15)
Hill “repeats” performed in this manner burn a lot of calories, because they force the larger muscles of your body (i.e. glutes) to do more work. They improve exercise economy as much as exhaustive distance training (16) but may help you avoid the disadvantageous fibre-conversion problems associated with extended steady state cardio.
"Economy is measured during the aerobic endurance test on the treadmill and is expressed simply as the volume of oxygen (VO2), relative to your body weight (ml/kg/min), that your body requires in order to run at a sub maximal speed. It is therefore a measure of the “cost of the body’s movement” during each stage of the test." (17) Now, as a lazy person, the word economy makes me nervous – makes me feel like I’m becoming an economy car. But wait: "As well as running for sufficient distances, running economy may also be improved by hill running or strength training. In particular, explosive strength training which includes sprinting, jumping and weight training using high to maximal movement speeds and low loads (up to 40% of 1 repetition maximum) can improve running economy." So, since weight training can improve running economy anyway, it's probably not worth worrying about for hill repeats performed once a week during a cut, okay?
Summarizing – we get to burn a lot of calories without needing to be fed extra calories or carbohydrate for the task. We improve the heart stroke, so resting heart rate goes down like it does with extended, boring steady state cardio, possibly with less risk of fibre-type conversion.
Increased heart stroke volume means increased VO2 and hence more oxygen circulating through your body. Lactic acid is a result of anaerobic metabolism (i.e. lifting), so with faster lactic acid clearance from the improved VO2 max, you’ll experience less fatigue you’ll lower the rate of lactic acid build-up.
This all means you’ll improve your endurance and conditioning, so you can lift longer and harder.
How often: Hill training is intense. Do this type of cardio at most once a week (18), on its own day – i.e., not on a training day – if for no other reason than they’re really hard!
What to eat: Because the interval portions of hill repeats are still in the aerobic end of the exercise world – i.e. fat is the predominant fuel substrate - feed days with hills the same as you’d feed a rest or SS cardio day: hill repeats don't need fuelling like HIIT does.
Sample 40-minute hill-repeat workout
(3 – 5 minute warm-up at 2% grade)
4 minutes at 4% grade
1 minute at 2% grade
4 minutes at 5% grade
1 minute at 2% grade
4 minutes at 6% grade
1 minute at 2% grade
4 minutes at 7% grade
1 minute at 2% grade 4 minutes at 8% grade
1 minute at 2% grade
4 minutes at 9% grade
1 minute at 2% grade
4 minutes at 10% grade
1 minute at 2% grade
4 minutes at 11% grade
1 minute at 2% grade
(2 – 10 minute cool-down at 2% grade)
For hills, the individual determines the difficultly level. You can run, walk, or do any combination of the two (note that you may not be running very fast at a 9-12% grade!). You start with the incline and go hard for four minutes at whatever level “hard” is for you. Then slow it down with less incline for a minute. Increase to the next incline level for the next hill interval, and then slow it to the same level as the first rest for a minute. The speed may vary week by week, according to your energy levels.
Feel free to fiddle with the grades and the speeds – your fitness level will dictate how fast and how steep you can go. While you’re new to this, you may choose to use a flat grade for recovery and start at a 1% grade for the first “hill”. You’ll be able to build this up as your stamina improves.
(Low Intensity) Steady State Cardio
The good
Steady State (SS) cardio is often over-stressed and may be over-rated as a principal exercise modality, but it isn’t entirely useless. Research has shown that capillary density increases with low intensity cardio (19), and that means better blood supply to the muscles. It also translates to improved lipid profiles, possibly because of the improved glucose uptake due to this improvement in blood supply. And it can be helpful as a form of active recovery from more intense forms of activity. (20)
When trained subjects were tested at 25%, 65%, and 85% of maximal oxygen consumption (VO2max), plasma glucose tissue uptake and muscle glycogen oxidation increased in relation to exercise intensity, while peripheral lipolysis was stimulated maximally at the lowest exercise intensity. (21)
Furthermore, low-intensity steady-state cardio isn’t particularly taxing to the body’s resources, an important consideration for athletes looking at avoiding overtraining, particularly in a caloric deficit.
The bad
That being said, while SS cardio is not particularly catabolic, it doesn’t create much of a caloric deficit. There is also an increased risk of repetitive strain injury (talk to any marathon runner). And there is evidence that extended endurance training promotes a transition from type II to type I muscle fibre types. (22) This is one REALLY important reason why it is so important to incorporate other types of cardiovascular training into your programme.
Endurance training has another ugly side – although fat oxidation increases in trained athletes, with conditioning, more and more of this fat comes from muscle triglyceride (23) – meaning less and less comes from adipose tissue. It seems the body learns to store muscle triglyceride where it’s being used (24), so it’s available for energy more quickly that it would be from adipose tissue – a phenomenon Charles Poliquin so eloquently describes as “Kobe beef thighs and butt, all plump and marbled with fat inside”.
Conclusion: endurance training is less and less likely to lean you out as you get used to it.
And the ugly
Steady State cardio sessions of up to 60 minutes a day can be used as an option to drop calories further as your cut progresses. To alleviate boredom and introduce still more complexity, these can be split up into separate sessions on the same day or divided amongst different modalities – for example, 20 minutes of incline treadmill, 20 minutes of stair climbing, 20 minutes of cycling.
How often: Ohhh, this is a tough one. For physique goals, my gut says 3 hours a week at the most. If you’re doing more than this to lose weight, look first to your diet, then to different forms of cardio, such as HIIT and hill-repeats. If it’s because you enjoy it, well, I’m sorry, but I’m far too lazy to understand you. Maybe try to watch more TV…?
What to eat: Because SS cardio uses fat as the primary fuel substrate, it doesn’t require any particular feeding paradigms. On days with SS cardio, eat as you would have otherwise.
Post workout SS cardio
For the same reason as was found by Romijn et al (25) in the HIIT summary above, SS cardio following a lifting workout may burn off FFAs mobilized by the intense lifting.
It can also act as active recovery and a means of burning off accumulated lactic acid as a fuel (26), protecting the muscles from ensuing hardness, which, while temporarily attractive, may leave the athlete more prone to injury. As a final note, Cressey suggests the improved nutrient delivery and clearance of metabolic wastes (27) afforded by increased capillary density due to steady-state cardiovascular conditioning may serve to reduce DOMS (28) (delayed onset muscle soreness) – so all you exercise-masochists will have to find something else to enjoy about your killer workouts!
Selecting cardio modalities
Vary your cardio. As in all things, it prevents adaptation. “Lactate threshold is highly specific to the exercise task”. (29) Adaptation equals efficiency, and since the biggest reason – at least from a physique standpoint – to do cardio is to burn calories, it’s inefficiency that we want here.
EPOC increases with the intensity (and duration) of the exercise, but HIIT can lead to overtraining, and hill-repeats are extremely taxing.
SS cardio doesn’t burn much and can lead to the fast-twitch conversion problem discussed above, but it does create SOME caloric deficit and can be helpful for active recovery.
To get the most advantage from these various modalities, you may find the following strategy helpful: choose to perform at most one hill session, at most two (maybe three) HIIT sessions and at most three (? I’m lazy) (pure) SS cardio sessions a week, for a total of say, at most five weekly cardio sessions. Make sure at least one of your cardio sessions is something other than SS.
And start small – leave yourself room to ramp up cardio as you find you cannot bear to drop calories any further.
So, for example, in a given week:
• Two HIIT
• One HILLS
• One SS
OR
• One HIIT
• One SS
OR
• One HIIT
• One HILLS
• Two SS
OR
• One HILLS
• Two SS
Lyle McDonald suggests the following training sequence, assuming a four-day split with two upper and two lower body workouts: (30)
• Mon AM: intervals PM: lower body weights
• Tue: AM: aerobics PM: upper body weights
• Wed: Off (brisk walking would be allowed for active recovery)
• Thu: AM: intervals PM: lower body weights
• Fri: AM: aerobic PM: upper body weights
• Sat: Off (brisk walking would be allowed for active recovery)
• Sun: Completely off (everyone should take at least one day off per week).
As an alternative to the “AM intervals – PM weights” setup (not all of us can hit the gym twice a day), HIIT may be performed after leg workouts, although you MAY be a tad unstable doing sprints after a heavy squat workout …(maybe use the bicycle for that one!).
How to do cardio if you MUST, first month
For someone dieting at a modest deficit (15-20% reduction from maintenance calories and optionally carb-cycling with high/low or high/medium/low carb days) and using Baby Got Back (31) as a lifting split, here’s sample cardio protocol you could use. If you were planning to try a thermo, Nitor or Thermocin would be excellent choices – stack either with Creatine and Nitrean. And as you ease into HIIT, you might appreciate what ETS can do for you.
Day 1 – Horizontal Push Pull – high (or medium) carb day
Week 1. 20 minutes of SS cardio in the AM or 20 minutes right after lifting.
Week 2. 20 minutes of SS cardio in the AM and 20 minutes right after lifting
Week 3. 25 minutes of SS cardio in the AM and 20 minutes right after lifting.
Week 4. 30 minutes of SS cardio in the AM and 20 minutes right after lifting.
Max 60 minutes SS cardio for the day as your cut progresses
Day 2 – Quad Dominant – high carb day
Week 1. 20 minutes of SS cardio in the AM or 20 minutes right after lifting.
Week 2. 20 minutes of SS cardio in the AM and 20 minutes right after lifting.
Week 3. HIIT in the AM OR right after lifting; 5 – 20:40 work:recovery intervals;
– start and finish with SS for a total of 20 minutes.
Week 4. HIIT in the AM OR right after lifting; 6 – 20:40 work:recovery intervals;
– start and finish with SS for a total of 20 minutes.
Add one extra sprint per week – Max of twelve 20:40 sprints as your cut progresses
Day 3 – Rest – low carb day
Day 4 – Vertical Push Pull – high (or medium) carb day
Week 1. 20 minutes of SS cardio in the AM or 20 minutes right after lifting.
Week 2. 20 minutes of SS cardio in the AM and 20 minutes right after lifting
Week 3. 25 minutes of SS cardio in the AM and 20 minutes right after lifting.
Week 4. 30 minutes of SS cardio in the AM and 20 minutes right after lifting.
60 minutes max for the day as your cut progresses
Day 5 – Ham Dominant – high-carb day
Week 1. 20 minutes of SS cardio in the AM or 20 minutes right after lifting.
Week 2. 20 minutes of SS cardio in the AM and 20 minutes right after lifting.
Week 3. 20 minutes of SS cardio in the AM and 20 minutes right after lifting.
Week 4. HIIT in the AM OR right after lifting; 4 – 30:60 work:recovery intervals;
– start and finish with SS for a total of 20 minutes.
Add one extra sprint per week – Max of eight 20:40 sprints as your cut progresses
Day 6 – No lifting – low carb day
Week 1. Half hour moderate intensity SS cardio
Week 2. 20 minutes of hill-repeats
Week 3. 25 minutes of hill-repeats
Week 4. 30 minutes of hill-repeats
Max for hill repeats is 40 minutes. You’ll know why when you do ‘em. <smirk>
Day 7 – Rest – low carb day
**Always give yourself at least one full day without training**
Written by MariAnne Anderson, BSc, MSc (B) - Copyright 2007
If you have a question or would like to make a comment about this article, you can do so on a dedicated thread in our bodybuilding, weight lifting and fitness forums
About MariAnne Anderson, BSc, MSc (B)
MariAnne is an iron geek who holds degrees in Statistics and Operations Research. Her formal education in research drives her to seek out the most efficient paths to physique enhancement: how to gain the most muscle with the least fat, and how to lose the most fat with the least muscle. To a mathematician, it's constrained optimization - to a bodybuilder, it's how to get the job done.
References
1. Direct Comparisons of Fuel use during Low, Moderate, and High Intensity Exercises ; Researched and Composed by Jacob Wilson and Gabriel "Venom" Wilson
http://www.abcbodybuilding.com/Nutrientpartitioningpart4.php
2. Yes, I actually put the words hating, unpleasant, distaste, and loathing in the same paragraph. I eschewed repugnant and abhorrent because I felt they were too elegant for something so vile (ooooh, another adjective!)
3. Cardio Progressions; Are you getting the most out of your cardio training? by Dr. John M. Berardi
http://www.t-nation.com/readTopic.do?id=1096984
4.
http://www.abcbodybuilding.com/Nutrientpartitioningpart4.php , which references
Relationship between fatty acid delivery and fatty acid oxidation during strenuous exercise. Romijn JA, Coyle EF, Sidossis LS, Zhang XJ, Wolfe RR. J Appl Physiol. 1995 Dec;79(6):1939-45.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
5.
http://www.bodybuilding.com/fun/par46.htm
6.
http://www.ultrunr.com/hiintense.html Effects of High-Intensity Intermittent Training on Endurance Performance
7. Acute and chronic responses of skeletal muscle to endurance and sprint exercise. A review. Abernethy PJ, Thayer R, Taylor AW.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
8.
http://www.bodybuilding.com/fun/par46.htm
9. Bloom SR, Johnson RH, Park DM, Rennie MJ, Sulaiman WR.Differences in the metabolic and hormonal response to exercisebetween racing cyclists and untrained individuals. J Physiol1976;258:1–18.11
10. Am J Physiol. 1998 Aug;275(2 Pt 1):E332-7.Utilization of skeletal muscle triacylglycerol during postexercise recovery in humans.Kiens B, Richter EA.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
11. If you do this with a friend, it looks like a really fast versio of the treadmill dance:
http://www.youtube.com/watch?v=aeeR4Vnvs8U
12. Lyle McDonald, cited
http://www.bodyrecomposition.com/forums/showthread.php?t=5828
13.
http://www.letsrun.com/2004/jkoxygen.php
14.
http://www.runnersworld.co.uk/news/article.asp?UAN=159
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http://www.hojohnlee.com/running/2006/02/
16. Med Sci Sports Exerc. 1998 Aug;30(8):1250-6. Improved running economy following intensified training correlates with reduced ventilatory demands.Franch J, Madsen K, Djurhuus MS, Pedersen PK. (
http://www.ncbi.nlm.nih.gov/entrez/...10865&query_hl=13&itool=pubmed_DocSum
17.
http://www.eis2win.co.uk/gen/news_runningeconomy.aspx
18.
http://www.runnersworld.co.uk/news/article.asp?UAN=159
19. 1: J Atheroscler Thromb. 2002;9(1):78-85. Effects of low intensity aerobic training on skeletal muscle capillary and blood lipoprotein profiles.Shono N, Urata H, Saltin B, Mizuno M, Harada T, Shindo M, Tanaka H. Department of Community Health Science, Saga Medical School, Japan.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
20. Cardio Confusion - Implications for Strength and Power Athletes, Eric Cressey
http://www.t-nation.com/readTopic.do?id=548070 which references Tesch, P. A., and J. E. Wright. Recovery from short term intense exercise: its relation to capillary supply and blood lactate concentration. Eur. J. Appl. Physiol. Occup. Physiol. 1983; 52: 98-103.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
21. Am J Physiol. 1993 Sep;265(3 Pt 1):E380-91. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration.Romijn JA, Coyle EF, Sidossis LS, Gastaldelli A, Horowitz JF, Endert E, Wolfe RR.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
22. J Sports Med Phys Fitness. 2000 Dec;40(4):284-9. Related Articles, A decade of aerobic endurance training: histological evidence for fibre type transformation.Thayer R, Collins J, Noble EG, Taylor AW.
http://www.ncbi.nlm.nih.gov/entrez....bstract
23. Med Sci Sports Exerc. 1997 May;29(5):635-9. Effect of endurance training on fatty acid metabolism during whole body exercise.Martin WH 3rd.
http://www.ncbi.nlm.nih.gov/entrez....9140900
24. Pflugers Arch. 2006 Feb;451(5):606-16. Epub 2005 Sep 10. Increased intramuscular lipid storage in the insulin-resistant and endurance-trained state.van Loon LJ, Goodpaster BH.
http://www.ncbi.nlm.nih.gov/entrez....6155759
25. Relationship between fatty acid delivery and fatty acid oxidation during strenuous exercise.Romijn JA, Coyle EF, Sidossis LS, Zhang XJ, Wolfe RR. J Appl Physiol. 1995 Dec;79(6):1939-45.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
26. J Appl Physiol. 1999 Nov;87(5):1684-96. Active muscle and whole body lactate kinetics after endurance training in men.Bergman BC, Wolfel EE, Butterfield GE, Lopaschuk GD, Casazza GA, Horning MA, Brooks GA.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
27. Tesch, P. A., and J. E. Wright. Recovery from short term intense exercise: its relation to capillary supply and blood lactate concentration. Eur. J. Appl. Physiol. Occup. Physiol. 1983; 52: 98-103.
http://www.ncbi.nlm.nih.gov/entrez...._docsum
28. Cardio Confusion - Implications for Strength and Power Athletes, Eric Cressey
http://www.t-nation.com/readTopic.do?id=548070 which references Tesch, P. A., and J. E. Wright. (1983)
29.
http://home.hia.no/~stephens/lacthres.htm
30. Bodyrecomposition Newsletter: May 17, 2006
