Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Clydesdales/Athenas (200+ lb / 91+ kg) Looking to lose that spare tire? Ideal weight 200+? Frustrated being a large cyclist in a sport geared for the ultra-light? Learn about the bikes and parts that can take the abuse of a heavier cyclist, how to keep your body going while losing the weight, and get support from others who've been successful.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-06-07, 03:57 PM   #1
VTRoadie
Weekend Warrior
Thread Starter
 
Join Date: Jun 2007
Location: Vermont
Bikes: 06 K2 Mach 2.0 (105 Grouppo), 04 Something Rambler Hardtail (Deore/Deore XT), 03 Nirve DSX-1 (Suntour/Deore/Deore LX)
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Kinda Silly - Why can I go longer on flats?

I have been doing 20-25-30 mile jaunts on my roadbike at a decent clip, usually burning 1000-1500 or more calories on my roadbike. At the end I feel awesome, but my legs are exhausted.

I broke my wheel (silly spokes), and haven't been in a fix-it mood lately, so I just took a climb on my mountain bike. I did a ~7 mi loop, half up hill (pretty gnarly, 6mph climb for 15 minutes). My heart rate was ~165 the entire time. Mapmyride/my garmin both say ~530 calories. I am dead exhausted (more so than a long road bike trip on fairly flat).

My question is ... Why can I burn so many more calories on long rides, but right now I dont think I could go another 10 feet after the climb? Is it simply a matter of output power (ie, pretty near to max output climb for 15 minutes, vs a 80% max effort road bike?)

Is there a benefit to the high intensity climb over a longer higher-calorie ride?
VTRoadie is offline   Reply With Quote
Old 08-06-07, 04:24 PM   #2
Tom Stormcrowe
Out fishing with Annie on his lap, a cigar in one hand and a ginger ale in the other, watching the sunset.
 
Tom Stormcrowe's Avatar
 
Join Date: Mar 2006
Location: South Florida
Bikes: Techna Wheelchair and a Sun EZ 3 Recumbent Trike
Posts: 16,118
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You're getting into the aerobic vs anaerobic debate.

Aerobic= lower HR and long period of activity at a lower caloric burn, but a greater % of that burn is from fat stores rather than protein.

Anaerobic= High Intensity, with a greater portion of the energy provided from protein burn.


How Cellular Metabolsism works

These both start occurring after you switch from the carb/sugar burn in the Kreb Cycle to the anaerobic cycle where you get your energy from fat and protein breakdown. The anaerobic cycle does provide 5X the energy that the Kreb cycle does, but it's a slower process to initiate. Both cycles produce a compound called ATP (Adenotriphosphate) and this powers the muscles.

When you are exercising over a longer period, at lower intensity, there is less stress on the muscle tissue, consequently less muscle breakdown. The body will pull a greater amount of it's energy from the fat, but not all of it to produce ATP and Glucose from your bodies reserves.

When you go high intensity and are operating at or near Max HR, your body thinks it's in crisis mode and it doesn't care where it gets it's energy short term, so it goes for protein because it's easier to break down than fat. It thinks it's in survival mode because you are running away from a predator, in effect, or are the predator yourself and need that burst to acquire nutrients. One of the side effects of this is during the repair process, the body concentrates on rebuilding your fast twitch muscle tissue first instead of Slow twitch.
As to which is which? On a chicken, the fast twitch muscle is the white meat and the slow twitch is the dark. Fast twitch is for explosive bursts of activity, and slow twitch is for the all day grind.

I mix it up activity wise to develop and maintain both.
__________________
. “He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you.”- Fredrick Nietzsche

"We can judge the heart of a man by his treatment of animals." - Immanuel Kant
Tom Stormcrowe is offline   Reply With Quote
Old 08-06-07, 05:16 PM   #3
Halthane
Senior Member
 
Join Date: Dec 2006
Location: Manhattan KS
Bikes: 2001 Giant OCR w/105-10spd, Schwinn High-Plains Built for Commute plus 3 Others in Various Stages of Rebuild/Repair
Posts: 431
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
+1 to what tom said
Halthane is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:12 PM.