I did the Sandia Crest Road Race over the weekend (us measly Cat 4s did 27 miles with ~5,000 ft of vertical.) Something I noticed, and I have also noticed it in the past when I am cooked towards the end of a race, is that I was completely cooked, was working to turn my legs over (even with a 27t cog), and wanted to stop (but didn’t), and my heartrate dropped. If I surged my heartrate would come up just a little bit but I would quickly feel like passing out. By the end I felt like I was working about as hard as I could, but my HR had dropped into the top of Zone 2!!
When this happens is it because I am suffering from a major bonk, or is it a case of my muscular endurance running out so my legs can no longer work hard enough to elevate my heartrate (or make me go fast)? I was cooking along just fine early in the race with my heartrate up in Z4, and it shouldn’t be an overtraining issue because I am just coming off a short break.
Does anybody else experience this? Your body feels like it is at the limit buy your HR is low enough that your monitor is looking for extra work on the side?
Been happening to me a lot of late. I am ok to ride at 85% but once we get into 90s (or any major climbs) its a whole different story. I think I am in worse form now than in winter or early spring. Recovery is the problem for me, feels like I have no gas when the race really starts, but i have been racing just about every weekend since end of April. Been experimenting with the right mix of protein/carbs/fat, getting more sleep and generally really trying to get off my feet when ever possible. If you find an answer that works for you please share and like wise.
You didn’t specify how long this took. If this happened after about 60-120 minutes, you probably bonked. What do you mean by muscular endurance running out? Are you properly eating and hydrating leading up to and during events? HR could be an indicator of many things but I tend to not look at those things during a race - the only thing important in a mass start race is keeping up or dropping people.
I have the same question. For me, I don’t think it is a bonk. I know a bonk. Personally, I think it is Muscular Endurance. It has also been suggested that it may be dehydration, but I don’t by that one. I think the muscles are just tired of working, and since they are not working, they don’t need a lot of oxygen, and therefore no demand on your heart to pump blood. That’s my theory.
If it is a muscular endurance issue you should feel a loss of power in your legs with little effect elsewhere. Your legs would feel trashed but you would generally feel OK. With a bonk, you would feel really bad overall. I felt this way by mile 20 of the Ironman. I had nothing left. All of my energy was zapped. Probably a bonk. Just my opinion.
It would be interesting if someone could explain the dynamics of muscle endurance. Giving a muscle all the oxygen and fuel (what’s that? glycogen?) and considerable flushing of waste products, what causes a muscle to give up? Especially when it’s a constant, low to moderate effort level, but repeated for a long time.
I’d say no on the dehydration as well. Symptoms of dehydration are slower pace and skyrocketing HR. Blood volume is lower so the heart has to beat faster to deliver the same amount of fluids at the same pressure etc.
A very interesting qustion and one I’m far from qualified to answer…none the less a few interesting things I’ve heard.
One of the most interesting “possibilities” is that it’s not the muscles giving up but the neural pathways burning out or fatiguing. It made some sense to me when it was explained in the sense of weight lifting. Apparently, and don’t quote ne here, alot of the initial gains made in weight lifiting are not from increased musle mass but simply training the neural pathways to “recruit” more muscles cells at the same time.
Taking this to the endurance scenario it seems to me that the possibility exists that pathways become “accustomed” to the constant use and burn out later and later. Thus increasing your endurance.
Interesingly looking up the subject in Noakes Lore of Running there appears to be scant little info…that I could locate, it’s probably in there just not that I coudl find right off.
A few things.
Limits on event lasting from 10 to 60 minutes appears to be from the athletes abilties to consume oxygen or VO2max. For events from 10 to 100 miles (Running) one study states that " exahstion of the material of the muscle or incidental disturbances which might make a man stop before his muscular system has reached it’s limit" (A.V. Hill 1925(a very old study should be something newer I suspect)) IOW we probably quite becaue the body says “You’re tired”. MAybe there is something to be said about this distance stuff being in ones mind.
I’ve read a couple of other articles that have stated similar but just as “vague” descriptions of why we stop. I’ve not seen to many things that come right out and give a reason for long distance fatigue, outside of a true “Bonk”.
Again no expert here I’m sure someone else has better info.
you probably couldn’t maintain a certain power output because you ran out of glycogen fuels and as a result you were unable to maintain blood sugar levels. The combination of relying on lipid oxydation and trying to race is a bitch. Aka bonking… focus on your nutrition. good luck
This is easy. If it were a bonk, you’d have a rather rapid decrease in ability… BAM, the tank goes dry. Fire down some sugar and you’d feel better. An end to your muscular endurance (or really, plain old endurance) would be a much more gradual thing.
you’re leaving out some important information, e.g., how far into the race (time) this happened, and what your nutrition was like until then.
But as I’m guessing, I’ll assume that about 22 or so miles w/ about 4000’ climbing would take a Cat 4 about b/w 75 and 90 min, which makes me think you were bonking. But you were probably dehydrated as well (Albuquerque combined w/ being a Cat 4 - little or no support).
Muscular endurance is a little bit of a fishy term in Exercise physiology, but is sometimes used to describe intermediate-duration efforts. Either way, unlikely to be the reason of your problems if you did ok on longer climbs before things started to go sour.
Race was about 27 miles, and my HRM said just under 5000 ft of climbing.
First half of race (13.5 miles) was relatively gradual climbing (or rolling with net elevation gain), then the second half of the race was up the Crest road.
My total time was 2:23, but this includes a relatively moderate pace for the first several miles. The main decrease in heart rate started to kick in at around 1:45.
I had two full bottles of Gatorade, but did not have any gels or solid foods. I spread out my drinking so that I finished both of them but did not do so long before the end.
Did a moderately paced ride the day before of 40 miles, 2000 ft of climbing, on the cross bike with some surges at the end.
w/ 2 bottles of G-rade, you’re definitely running into a big electrolyte deficit, for starters. Combine that w/ dry weather (sweating w/out feeling it), and you’re in trouble pretty quickly. For starters, read up on fueling before and also during a race (60 g/hr is a good number to start with), and electrolyte replacement. G-rade is actually marketed as a low-sodium food, I think. You can lose up to 1 g of sodium per hour through sweat. Also, potassium levels are important during physical activity.
Good place to start: McArdle, Katch, Katch: Exercise Physiology. Should be 5th or 6th ed. by now. Great, great text for those interested in exercise phys., and also has a big nutrition section.
300 calories for a 27 mile race with climbing 5000 ft? Did you preload before the race really well? Have you done this course before and had better results? If not it sounds like a bonk to me.
Another possibility is that you are overtrained and your heart needs rest.