Sunday 12 January 2014

What is LISS Cardio? C| ShreddedRevolution.comShreddedRevolution.com

HIIT & LISS Cardio for Fat Loss | ShreddedRevolution.comShreddedRevolution.com

What is LISS Cardio?


Low intensity, steady-state cardio means exactly that; working for prolonged periods of time at 60-75% of your MHR rate. This is known as the aerobic training threshold; where sufficient oxygen is available for a muscle to function without using glucose as an energy source.
 
In the aerobic threshold, fat is oxidised and used as a primary energy source. This makes fasted LISS cardio favourable with many athletes, as adipose (fat) stores in the body are used for energy. 
 Many athletes also choose to use shorter periods of LISS as a form of active recovery; pumping nutrient-rich blood to muscle tissue.

LISS Calorie Expenditure

Calorie expenditure during LISS is significantly lower than during HIIT on a per-minute basis; however, whereas HIIT requires resting periods at a lower heart rate, LISS can be performed at a consistent level with a calorie expenditure of roughly 10kcal per minute depending on the person. 

Two major issues with LISS are:

A) It can become incredibly tedious, especially with low energy levels whilst dieting.

B) It actually takes a significant amount of discipline for athletes to remain within the low intensity training threshold. Increasing intensity and crossing over training thresholds can begin to cause catabolism, especially if muscle and liver stores are depleted of glycogen.

LISS & Carbs

As we’ve discussed, LISS cardio results in fat being used as a primary energy source, making it an incredibly effective tool whilst implementing low-carb diets such as the Atkins diet and other ketosis-based diets.

Article by Andy Robinson

Bibliography
(1, 2) Layne E. Norton
(3, 4) Wilson, et al. Concurrent Training: A Meta Analysis Examining Interference of Aerobic and Resistance Exercise. University of Tampa, FL. J Strength Conditioning.
(5) Naito, et al. Satellite cell pool enhancement in rat plantaris muscle by endurance training depends on intensity rather than duration. Juntendo University, Japan. Acta Physiologica. 2011 Oct.

Prof. Dr. Andro « Paleo Diet – Paleolithic Diet Research, Primal Nutrition, Low-carb eating, Eat like a caveman

Prof. Dr. Andro « Paleo Diet – Paleolithic Diet Research, Primal Nutrition, Low-carb eating, Eat like a caveman

As the data in figure 2 tells you, there is no difference in the following hours and – what’s even more important – the total energy expenditure was identical – 2594kcal/day vs. 2589kcal/day in the before and after breakfast trial, respectively. In addition to that, a detailed analysis of the unpublished study by Shimada et al. the above data was taken from, does also show that
  • working out before breakfast reduces the energy expenditure in the time before lunch –  over the whole period the subjects burned about 500 kcal less, when exercise was performed before breakfast
  • working out before breakfast burns more glycogen and increases non-oxidative carbohydrate storage during / after breakfast — with the carbohydrate content of the breakfast being used for glycogen repletion, this does in fact lead to another increase in fatty acid oxidation, simply because the alternative fuel, namely the carbs are not oxidized, but stored
So, 2x thumbs up for cardio before breakfast – at least in the short run and when your goal is to maximize fatty acid oxidation, but …

Is maximal fatty acid oxidation even what you should be aiming for during a workout?
I guess you will already have read between the previous lines that my answer to this question is a definitive “no”. Moreover, most of you are so clever and have been following the SuppVersity posts for so long that they could come up with their own arguments against an overemphasis of intra-, post and total 24h fatty acid oxidation, when getting lean and healthy is your goal. And probably, some of them are even identical to mine:
  • Firstly, and most importantly, burning fatty acids for fuel does not equate fat loss. If you follow a real ketogenic diet (not one with tons of protein in it), you’ll burn (almost) exclusively fat, but even under these “extreme” conditions most of the fat will come from the fat you eat, while the small amount that’s actually taken from your hips, buttocks and whatever, will be restored unless you are in a caloric deficit, when your fatty acid oxidation will increase anyways.
  • The “Fat Loss Support Routine” from the Step By Step to Your own Workout Routine guide would be one example of how you can structure your weekly workout regimen to cut body fat.
    Secondly, many of the metabolic benefits of exercise are closely related to the act of glycogen depletion. This is particularly true for the increase in GLUT-4 expression and consequent improvements in muscular glucose uptake, burning only fat for fuel during a workout is thus a questionable ideal.
  • Thirdly, working out “in the zone” may burn the most fat but won’t have the conditioning effects high(er) intensity workouts have. While obese individuals and people who have been sitting around their whole lives will see improvements in their VO2max (and in the long run their heart-health), anyone who is not totally unconditioned misses out on the structural changes in the musculature, and as you’ve learned on day one of the SuppVersity Exercise Science Week adipose tissue, as well.
In short, the importance of burning fat for fuel is so overrated that exercise prescriptions that are based on the paradigm of maximal fatty acid oxidation are at least suboptimal for health, fitness and physique purposes.

Some people, I guess, would probably even go so far to say that they do more harm than good. I for my part leave it up do you to decide whether you join sides with my carefully worded or the more extreme version of this conclusion, or – and this would be your good right – to wholeheartedly disagree with both of them.
References:
  • Ballor DL, RE Keesey. A meta-analysis of the factors affecting exercise-induced changes in body mass, fat mass and fat-free mass in males and females. Int J Obes. 191; 15: 717-726.
  • Bielinski R, Schutz Y, Jéquier E. Energy metabolism during the postexercise recovery in man. Am J Clin Nutr. 1985;42: 69-82.
  • Dionne I, Van Vugt S, Tremblay A. Postexercise macro-nutrient oxidation : a factor dependent on postexercise mac-ronutrient intake. Am J Clin Nutr69: 927-930.
  • Donnelly JE, Smith BK. Is exercise effective for weight loss with ad libitum diet? Energy balance, compensation and gender differences. Exerc Sport Sci Rev. 2005; 33: 169-174.
  • Henderson GC, Fattor JA, Horninig MA, Faghihnia N, Johnson ML, Mau TL, Luke-Zeitoun M, Brooks GA. Lipolysis and fatty acid metabolism in men and women during the postexercise recovery period. J Physiol. 2007; 584: 963-981
  • Hill JO. 1992. Physical activity and energy expenditure pro-ceedings: national task force on prevention and treatment of obesity. Physical activity and obesity conference – NIDDK, pp.60-65.
  • Iwayama K, Tokuyama K. Exercise in a metabolic chamber – Effects of exercise on 24 h fat oxidation. J Phys Fitness Sports Med. 2012; 1(2): 307-316.
  • Melanson EL, Sharp TE, Seagle HM, Horton TJ, Do-nahoo WT, Grunwald GK, Hamilton JT, Hill JP. Effect of exercise intensity on 24-h energy expenditure and nutrient oxidation. J Appl Physiol. 2002; 92: 1045-1052 
  • Shimada K, Yamamoto Y, Iwayama K, Nakamura K, Ya-maguchi S, Hibi M, Nabekura Y, Tokuyama T (unpublished observation).
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Optimizing the "Fat Burning Zone" : Chronic Endurance Training Boosts Fatty Oxidation - Does More Help More? - SuppVersity: Nutrition and Exercise Science for Everyone

Chronic Endurance Training Boosts Fatty Oxidation - Does More Help More? - SuppVersity:Optimizing the "Fat Burning Zone" :

So, if it's not the volume, what determines the increase in fatty acid oxidation?

Rosenkilde have probably asked themselves something similar to the above, when they realized that there were no meaningful differences between the subjects in the medium vs. high dose cardio groups. The statistical analyses the researcher conducted did yet reveal, that

  • VO2peak, generally regarded as a marker of cardio-respiratory fitness,
  • fat free mass, the weight of everything (incl. bones, organs, etc.) that's not fat, 
  • cycling efficiency, the power output at a given VO2 peak, and the
  • mitochondrial complexes II–V, enzymes that facilitate the oxidation of fatty acids,
were all associated with higher increases in fatty acid oxidation, while the observed changes in fasting plasma insulin, glucose, FFA, or glycerol had no prognostic value with respect to the increase in fatty acid oxidation.
Don't forget that HIIT is an even more effective "long-term investment" in VO2 peak an mitochondrial power - just don't do it everyday | learn more
Bottom line: I guess you will start yawning, when I tell you that doing regular cardio training is not useful for its acute effects on energy expenditure (you know that, right?).

If you look around the gym, you will yet notice that "burning energy" is still what 90% of the cardio warriors have on their mind. What they fail to realize is that performing a sane amount of low-medium intensity cardio will be rewarded in the long run only and is (some of you may remember that from the SuppVersity Facebook News) associated with increased muscle strength throughout the life span (Crane. 2013), delays the age of decline in leg strength and muscle morphology (Tarpenning. 2004), improves muscle function in the elderly (Harber. 2009) and can have have minimal hypertrophy effects even in the elderly (Ozaki. 2013).