Metabolic adaptations facilitate lactic acid removal allowing you to perform exercise at a higher level of %VO2max for longer periods of time, and changes in lipid metabolism which will provide extra Calories from fat to supplement those from glycogen and glucose metabolism for any specified level of activity (%VO2max). The result is an increase in maximal performance and the ability to maintain a high level of performance for a longer time interval (endurance).
Training also improves the muscle's tolerance for the stresses of prolonged exertion. These include strengthening of the connective tissue between muscle fibers to minimize the microtrauma (and post exercise discomfort) that occur with with physical exertion. Not every training session (in your program) needs to stress the cardiovascular system. In fact a successful program needs to be balanced with at least two days per week at less than maximal cardiovascular intensity to allow for mental and physical recovery. And it has been demonstrated that your performance in a competitive event is better if you taper your training program in the week prior.
But before we get into the advanced course on training techniques, let's not forget our basics. If it is early in the riding season, or you have just decided to get back into riding again, the secret to preventing injuries and preparing yourself to get the most out of the training tips that follow, is to develop a good, personal mileage base. You may be fortunate enough to live in warmer, dryer climes, or been able to drag yourself to a spin class all winter. If not, the first order of business for the training year is to put some unstressed (no intervals, no sprinting up hills) miles on your bike (and body). It's not that intervals or hills are forbidden - but not too hard or too often. Remember, you're still banking foundation miles for the season. The best strategy is to let the terrain and how you feel (perceived exertion) tell you when to make that effort. If, at the end of the long ride, you feel like you could go out and put in a few more miles - you are probably doing it just right. A good target is a base of 500 miles - and as a rule of thumb, don't increase your weekly mileage by more than 10% as you are getting there.
As proof that there is an upper limit for the benefits of aerobic training, a group of swimmers training 1.5 hours per day was compared to a group training with two equivalent 1.5 hour sessions. There was no difference in the final performance, power, or endurance between the two groups. For aerobic training (continuous, not intervals) at less than 90% maximum heart rate it makes the most sense to look at the duration of the planned event, and train
TRAINING FREQUENCY
It appears that maximum aerobic conditioning (increasing VO2max) occurs with 3 workout
days per week. So unless one is trying to burn Calories to lose weight, or is working
on increasing mileage to get the musculoskeletal system (back, shoulders) in shape for a
long endurance event on the bike, it is better to take off 2 to 3 days per week to allow
for muscle and ligament repair and decrease the risk of cumulative stress resulting in an
increase in training injuries. And interestingly, it appears that these 3 days per week
will maximize aerobic conditioning equally in any combination - i.e. 3 days in a row
with 4 off, alternating days of exercise, etc.
Q. I was reading the other day in Joe Friels Cyclists Training Bible, he briefly mentions that training twice a day is better because you release a second dose of growth hormone during the day. I haven't found any literature behind his comment. Have you got in more info about training twice a day compared to once? - J.
A.I am unaware of any literature that supports twice a day training except as a way to work around a limited schedule (such as work committments). In fact I would suspect that if there is any effect it would be a negative rather than a positive compared to a single longer session.
Aerobic training (more important for cycling and other sporting events lasting more than 60 seconds) on the other hand provides its benefits by improving the cardiovascular and oxygen delivery systems to the muscle cell. These include improvements in both cardiac output (amount of blood pumped by the heart per minute) and at the muscle fiber level where there is an increase in the removal or extraction of oxygen from the blood cells in the capillaries. In addition, there is an improvement in the efficiency of the cellular metabolic pathways which convert glucose into ATP.
As the level of exertion (measured by %VO2max) increases, there is a slow transition towards anaerobic metabolism in the muscle. There are always areas of relatively lesser perfusion within the muscle that are functioning anaerobically. So even at 50 to 60% VO2max some anaerobic conditioning is occuring. But at 85% VO2max (the "anaerobic threshhold" for most individuals) there is an abrupt increase in anaerobic metabolism throughout the entire muscle. So even though some cross training of the anaerobic systems takes place during exercise at 60 to 80% VO2max, a training program for sprint performance needs to include several exercise sessions per week above 85%VO2max. Long slow distance may be good training for aerobic, endurance events, but it will not improve your sprint performance. Both aerobic and anaerobic exercise sessions need to be included in a training program, but it is the balance of the amount of each type of exercise (aerobic vs anaerobic; interval training, continuous training, and fartlek training) in the overall program which determines its suitability for the competitive event for which you are training.
If one is training for sprints of up to 20 seconds in duration (which do not involve significant lactic acid buildup and basically are training the ATP and CP systems), it is recommended that the duration of the training interval should be increased by 1 to 5 seconds over the usual best time for that sprint distance with exercise intensity or maximum effort being unchanged,. For example, if one is training for a 100 yard dash, and has a personal best of 12 seconds, the training interval should be a 13 or 14 seconds sprint at the same pace (ignoring the total distance being covered in the 13 or 14 seconds). And a relief period 3 times longer than the training interval is recommended for recovery - 42 seconds in this example.
Training for longer intervals (up to several minutes) produces significant lactic acid along with stressing the anaerobic metabolic pathways. To train for these longer distances (several minutes of maximum output), it is suggested that the distance being trained for be subdivided, and the training interval effort focused on that shorter distance. For example, if one is training for a personal best mile ride on the bike, and the best time for the entire mile is 3 minutes on the bike with the best 1/4 mile segment being 30 seconds and the best 1/2 mile segment being 80 seconds, the training interval could be set at either 1/4 or 1/2 mile and the time for this training interval set at your personal best minus 3 to 5 seconds. In this example the training interval might be chosen as 1/4 mile with a goal of a 25 second time. And the rest interval should be 2 times the training interval (as lactic acid clearance does not require the same recovery time as recharging the intracellular metabolic machinery).
But training program drop out rates can double when intervals are used, so they should be used judiciously. Don't use them all year round, consider a twice a week program during your peak season, and separate each session by at least 48 hours to allow adequate recovery. If your long ride is on the weekend, Tuesday and Thursday make the most sense. The goal should be 10 to 20 minutes of hard pedaling per training interval session, not counting warm up, recovery, or cool down. A good place to start is with 5 minutes of peak effort.
One approach is to use one day a week for short intervals (i.e. five 60 second and five 90 second intervals) and a second for longer intervals (two 3 minute and two 5 minute intervals). Allow 3 to 5 minutes for recovery between intervals and don't forget a 20 to 30 minute warm up and a 15 minute cool down. It has been shown that as few as a half dozen 5 minute intervals (separated by one minute recoveries) during a 300 km training week will improve both time trial and peak performance.
If you have a heart rate monitor, an alternative is to key intervals to your maximum heart rate. Ride your intervals at 80 to 90% of your maximum heart rate and spin easily until your heart rate drops to 60 to 65% of maximum.
This level of exertion can be maintained for hours at slightly less intensity than used in personal competitive events in the past, and is particularly suited for endurance event training. It is thought to have a preferential beneficial effect on the slow twitch muscle fibers (as opposed to the fast twitch fibers used in sprint interval training). It is suggested that a distance of 2 to 5 times the actual competitive event be chosen for this daily segment of the weekly training program.
PUTTING THIS ALL TOGETHER, a good weekly training program:
Aim for a total time committment per week of 10 hours. It's interesting that two of America's all-time great road riders, Greg LeMond and Connie Carpenter, both recommend the same total weekly training time -- 10 hours -- for fast recreational riders. They say if you devote that much to a mix to distance, speed, climbing and easy rides for recovery, you're likely to come close to your potential. And time on the bike seems to be the key, not the miles ridden. Lemond's Law is occasionally referred to in bike magazines. To paraphrase: when you record your daily workout, make your key entry the time you rode not how far you rode. The reason, says Greg, "twenty miles into a headwind is a lot different than 20 miles with a tailwind". The same holds for a ride in the hills vs. a ride on flat ground.
For most recreational roadies, 7-10 hours of riding per week is plenty for steady improvement if you have an intelligent training program.Wouldn't more be better? If you do try to add in extra hours, you risk bothy overtraining as well as the extra stress produced by more time on the bike. Both physical stress on your body and the pressure it puts on responsibilities to family, friends, and profession.