Heat Exhaustion and Heat Stroke Overview

Heat exhaustion: This condition often occurs when people exercise (work or play) in a hot, humid place and body fluids are lost through sweating, causing the body to overheat. The person's temperature may be elevated, but not above 104°F.

Heat stroke: This medical condition is life-threatening. The person's cooling system, which is controlled by the brain, stops working and the internal body temperature rises to the point where brain damage or damage to other internal organs may result (temperature may reach 105+°F).

NOTE: Good technique equals confidence that will increase your downhill speed. High speed without good technique could lead to disaster.

Some people like climbing, some people just love to climb, and there are those who see climbing as a means to an end. I am of the latter group. I climb hills for two reasons, first the hill is in my way of where I want to get and second is my love for the reward of descending. To quote John Swanda "a good descent is where I can reach 50 mph or more." As I grow older my need to streak down a hill at 50 mph has lost some of its appeal but I still love the thrill of a fast technical descent. So, let me delve into what it takes to descend with utter confidence and skill.

Where to Look: The first thing, and perhaps one of the more important techniques, is where to look while descending. Many new riders have a propensity to look about 5 feet in front of them which is just about the worse place you should look. The reason is, at just about any speed, if you see any hazard just 5 feet ahead you will almost certainly hit it. We know "You Steer Where You Look," therefore, it would be best to focus your gaze at least 20 feet ahead and further when possible. Doing this gives you time to react to any hazard you see and avoid it with time to spare. Once I see a hazard and have chosen a path around it I no longer look at it but keep my focus forward and allow my peripheral vision to keep me safe from the hazard. One phrase comes to mind and that is "Keep Your Chin Level with the Ground." In other words always look way ahead.

From RoadBikeRider.com

As cyclists we're responsible for knowing the state of our equipment. Periodic bike inspection is an absolute must. A crash demands an immediate exam -- especially when there's been an impact involving the front end.

The fork is probably the strongest single element of a bike. It takes a lot to damage one, but you must be absolutely sure all is well. After all, not much in life is scarier than a fork failure, and you don't want that on your mind -- like at descending speed. Let's look at two main ways forks get broken:

Front Wheel Impacts

This includes riding into a curb, into a nasty pothole, or into any other immovable object. You don't need to be going fast or even crash to ruin a fork. If you suspect it was damaged by a hard hit, get on the cell phone and call for a ride. Yours is over.

With a carbon fork, the damage may be internal and unseen. The fork must be pulled from the frame to check for injury to the steerer tube, the fork legs or the crown. A simple look while it's still in the frame is not enough. Take it out and put it under a bright light.

You're looking for cracks, dents, dings and bent or loose dropouts. Gouges, discoloration, peeling, delamination -- all spell impending disaster. So do buzzing sounds from inside the legs during riding. And then there's the tell-tale sensation that the bike doesn't steer or behave like it used to. If you lack the experience to do this kind of inspection, take your bike to the most experienced mechanic at your Local Bike Shop. He/she might just save your life.

Here's an excellent, albeit long, explanation of how best to mount a tire and tube by Lennard Zinn that appeared in Velo News.

Dear Lennard, Last season I experienced two sudden front wheel flats on long, two-mile, twisty and steep descents on hot summer days. Neither of these flats were puncture-related but instead were caused by the inner tube/tire blowing off the rim because of heat.
-Terry

Dear Terry,
I am willing to bet you that both of those flats were caused by the inner tube being caught under the rim bead. And catching the tube under the bead is far more likely to happen with a tight tire that you have to mount with levers. There is no way to get a long rip in a tube like that without blowing the tire off of the rim, and there is no way to get a tight tire to blow off of the rim without getting some inner tube underneath it to lift it off. Yes, the heat of braking precipitated the occurrence, but it was the trapped inner tube edge that, once the pressure came up enough due to the heat, blew the tire off.

When mounting any tire, but especially a tight tire, you need to make sure to finish at the valve stem, and not start at the valve like so many people do. This will significantly reduce the chance of that happening. Not only is tire installation best by finishing at the valve stem, but removal of the tire is also most easily accomplished by starting near the valve stem. That way, the beads of the deflated tire can fall into the dropped center (?valley?) of the rim on the opposite side of the wheel, making it effectively a smaller-circumference rim onto (or off of) which you are pushing the tire bead. If you instead push the tire bead onto (or off of) the rim on the side opposite the valve stem as a high percentage of people do, the circumference on which the bead is resting is larger, because the valve stem is forcing the beads to stay up on their seating ledges opposite where you are working.

Knee and hip pain are the most common cycling injuries. The most common cause of knee (and hip pain) in cyclists is iliotibial band (IT band) syndrome. The IT band is a thick fibrous band of tissue, which runs on the outside of the leg from the hip to the knee. Pain is caused when the band becomes tight and rubs over the bony prominences of the hip (greater trochanter) and/or the knee (lateral epicondyle). Tight inflexible lower extremity muscles may worsen the condition.

As injury is generally a problem of overuse, it is often seen in the cyclist just beginning a training program or early in the training season when the temptation is to do too much too fast. In order to minimize knee and hip pain in the early season, take it easy for the first few weeks - pedal with low resistance and keep that cadence up to at least 80-90 rpm allowing your body to adjust again to road riding. (Likewise with any change that leads to a slightly new bike position.) Minimize hard riding or hill work for the first few weeks. Add in a stretching program for your lower extremities, especially for the gluteus and IT band to help transition you into your riding season.

The most common causes are:

• Faulty saddle height or position
• Crank too long - especially if you have chondromalacia
• Pushing excessively high gears (slow cadence in cold weather)
• Too much leg work in the gym
• Cleat alignment
• Individual cyclist anatomy
• And finally don't forget about the low back as playing a role in leg pain - especially the back of the leg and hamstrings. All leg pain is not from problems "where it hurts".

Article from bikesplit.com

To get the most out of your cycling, you need to analyze your pedal stroke and identify the weak spots. There's more involved with efficient pedaling than just pushing downward with a lot of force. I've identified three points of your pedal stroke where you can gain energy output: Pushing forward over the top, pulling back at the bottom, and lifting the weight of your leg as it moves back up to the top during the 'backstroke.' Cycling isn't a natural motion that we've repeated every day since childhood, like walking is for running. Try to develop this pedaling power flow as I've described; it will be worth the effort. Without any extra work to increase aerobic capacity you can gain speed by perfecting your pedaling technique.

Figure 1. The difference in the leverage potential of the right crank arm with pedaling force applied from two different directions (clockwise crank rotation).

These examples are leading up to a thorough analysis of how to push in powerful circles with your legs. Figure 1 examines the critical range of motion over the top of the pedal stroke. This particular point of the pedal stroke can be either a powerless 'dead spot,' or an extra bonus bit of energy with a little technique work. The challenge is to push your foot forward over the very top of the stroke, and then continue the forward pressure as you begin your down stroke. Figure 1 illustrates the optimal direction of force (A) and the more typical, yet less effective direction of force (B). Figure 1 also shows the amount of leverage available with the average Pedal stroke (B), and the more efficient technique A). The diagonal line (A) which runs parallel to the crank arm represents the effective length of the lever when the pressure is applied perpendicular to the crank. The two lower lines (A) and (B) compare the difference of the effective lever length when the power is applied from direction (A) or (B). Notice that pushing from angle (B) directs about one third of the energy to pushing the crank arm toward the bottom bracket. This is similar to pushing the crank straight downward when it's at the 12 o'clock position. Direct downward force at the fulcrum (bottom bracket axle) contributes nothing to the turning or torque movement necessary to pull on the chain at the chain-rings, which in turn pulls on the sprockets at the back wheel. Therefore, with an equal amount of muscular power available, pushing only downward (B) can generate only two-thirds the force that is possible by pushing both forward and down simultaneously (A). In the weight room, the leg extension machine, (not the leg press) which focuses on pushing your lower leg forward from the knee, works well to develop this particular muscle action by developing your vastus-medialus (inner quad just above the knee).