Guest guest Posted September 14, 2004 Report Share Posted September 14, 2004 I know nothing of the Weir equation. However, from my exercise phys classes I do remember that the higher intensity the higher the percentage of carbs (glycogen) vs. Fat. So in your case, at a HR of 135bpm you my be using a higher percentage carbs. However, the key word is percentage. The more intense the workout is or the higher your HR is you will be burning more calories. There will be a higher percentage from carbs then fat but you would be burning more fat calories at the higher intensity then if you stayed at the lower intensity. For example This is just made up but is the idea Working at 135 bpm you my using 55% from fat and 45% from carbs and be burning say 600 cals/hr this means 330 cal. from fat and 270 from carbs Now say you worked at 160 bpm you may be using 40% from fat and 60% form carbs. Now if you work this out. With the higher intensity you burn more cal/hr say it 1000 cal/hr this means 400 from fat and 600 form carbs This is misrepresented everywhere except ex phys textbooks. An added bonus to working at a higher intensity is after you stop your body uses your fat to replace the lost glycogen in the muscle and blood stream. Therefore, you end up using more fat. The key is to work at 80%-85% of your HR reserve 220-age-resting heart rate=HR reserve (HRR) HRR x 80%or 85% then add back in your resting HR So, don't worry about that Weir equation and just work hard. In fact, the activity that burns the highest percentage of fat is sleeping. Hope This helps Mike Zawilinski NSCA-CPT Boston MA USA Zowiemonster@... > Dear Group, > > I recently had a VO2 max test done on an exercise cycle; on > completion of the test I was told that my calorie expenditure from > fat dropped off sharply when my heart rate went above 135bpm, the > tester told me that the Weir equation was used to determine this. My > question is this how accurate is the Weir equation in determining > fat calories used during exercise? And yes he is trying to sell > something hence my skepticism. > > > Regards > > Young, > London, U.K Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 23, 2004 Report Share Posted September 23, 2004 Unless the test utilized a gas-calibrated CO2 sensor (i.e. lab-style equipment), the ratio of fat to glucose is not accurate. It does make sense that your fat expenditure went down at 135 bpm since the body burns a higher percentage of glucose as you approach your anaerobic threshold. Your total calories burned will also increase as heart rate increases. As far as the Weir equation, it is frequently used in metabolic measurements, and quoted in many studies. According to the link below, it's accurate within 0.5%. However, since you were being solicited, I'd bet that the seller was twisting your test results to get you to buy some slickly marketed snake oil. http://ajpregu.physiology.org/cgi/content/abstract/258/6/R1347 Regards, Peggy Bowes Mesa, AZ Weir Equation Dear Group, I recently had a VO2 max test done on an exercise cycle; on completion of the test I was told that my calorie expenditure from fat dropped off sharply when my heart rate went above 135bpm, the tester told me that the Weir equation was used to determine this. My question is this how accurate is the Weir equation in determining fat calories used during exercise? And yes he is trying to sell something hence my skepticism. Regards Young, London, U.K Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 26, 2004 Report Share Posted September 26, 2004 Thanks to Mike and Ralph for their responses. I'm afraid that I didn't make myself as clear as I should have. Both of your answers encompass my own feelings toward burning body fat (not that I'm that successful at it!), as in it's not the percentage but the total that matters, obviously another consideration would be increasing lean body mass as a way of facilitating fat loss. Anyway the point that I was trying to make was that during this test where I used a modern day equivalent to a bag I was told that as my heart rate went above 135BPM the kcal's being used from fat dropped off sharply, I don't have the figures to hand but from memory at a HR of 140 I was burning about a third of the amount of fat that I was burning at 130BPM (not percentage wise but total). The chap administering the test showed me this on his flash computer printout and I asked him how, from just oxygen exchange could the amount of fat being used be measured? I thought that blood tests were needed, he said that the Weir equation was used in the programme to determine the amount of fat being burnt -hence my question. As I stated in my first post something is being sold here, this company wants to visit our gym every few months and do this same test on our members to inform them of what their HR should be when doing cardio to optimise fat loss. Now if this Weir equation is accurate then they're probably going to be allowed in. I think that there is enough gimmickry in the fitness industry and I really don't want to encourage any more; so the question remains does anyone know if there's any accuracy ion this test? Many Thanks Young, L ondon, UK wrote: > > > I know nothing of the Weir equation. However, from > my exercise phys > classes I do remember that the higher intensity the > higher the > percentage of carbs (glycogen) vs. Fat. So in your > case, at a HR of > 135bpm you my be using a higher percentage carbs. > However, the key > word is percentage. The more intense the workout is > or the higher > your HR is you will be burning more calories. There > will be a higher > percentage from carbs then fat but you would be > burning more fat > calories at the higher intensity then if you stayed > at the lower > intensity. > > For example > This is just made up but is the idea > > Working at 135 bpm you my using 55% from fat and 45% > from carbs and > be burning say 600 cals/hr this means 330 cal. from > fat and 270 from > carbs > > Now say you worked at 160 bpm you may be using 40% > from fat and 60% > form carbs. Now if you work this out. With the > higher intensity you > burn more cal/hr say it 1000 cal/hr this means 400 > from fat and 600 > form carbs > > This is misrepresented everywhere except ex phys > textbooks. > An added bonus to working at a higher intensity is > after you stop > your body uses your fat to replace the lost glycogen > in the muscle > and blood stream. Therefore, you end up using more > fat. > > The key is to work at 80%-85% of your HR reserve > > 220-age-resting heart rate=HR reserve (HRR) > HRR x 80%or 85% then add back in your resting HR > > So, don't worry about that Weir equation and just > work hard. In > fact, the activity that burns the highest percentage > of fat is > sleeping. > > Hope This helps > > Mike Zawilinski NSCA-CPT > Boston MA USA > Zowiemonster@... > > > > > Dear Group, > > > > I recently had a VO2 max test done on an exercise > cycle; on > > completion of the test I was told that my calorie > expenditure from > > fat dropped off sharply when my heart rate went > above 135bpm, the > > tester told me that the Weir equation was used to > determine this. > My > > question is this how accurate is the Weir equation > in determining > > fat calories used during exercise? And yes he is > trying to sell > > something hence my skepticism. > > > > > > Regards > > > > Young, > > London, U.K Quote Link to comment Share on other sites More sharing options...
Guest guest Posted September 27, 2004 Report Share Posted September 27, 2004 Ralph Giarnella MD writes a great anerobic/aerobic review(see earlier) A friend of mine using my XYZ interval training, maintained heart rate measures for 2 different intensities. Each was performed at 3 PM. The lower intensity(LI)was performed at; 5 sets of max effort for 15 secs with a rest of about 2 minutes between max efforts, then 10 minutes of mid range (140-148 BPM) aero/anerobic?? exercise Five days later the high intensity(HI)was performed at; 5 sets of max effort for 30 secs on, 10 secs. off, 15 secs on, X's 4 sets with a rest of about 3.5-5 minutes between max efforts, then 10 minutes of mid range (140-148 BPM) aero/anerobic?? exercise. He then tracked heart rate the remainder of the day until midnight. He Is 61, quite muscular, and has a rising from sleep heart rate of 40! which is down from 56 after initiating this type of interval training. Max heart rates during the training; HI 171(a personal best an 10 over his age group hi) and LI 154. At 1 hour after exercise HI, 94; LI, 72. At 2 hours after exercise HI, 78; LI, 60. At 4 hours after exercise HI, 66; LI, 60. At 7 hours after exercise HI, 60; LI, 60!?. At 9 hours after exercise HI, 60; LI, 46! He slept well after the LI but was restless after the HI and awoke about 3 times after the high intensity (unfortunately not taking his heart rate) He alleges he sleeps well if he performs the HI training at 10-11AM. The question begging an answer is; how much fat burning takes place after the interval training? Activity intensity is low throughout the remainder of the day. Jerry Telle Lakewood Colorado USA << Quote Link to comment Share on other sites More sharing options...
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