In a typical, near PR time 5K race, the athlete will spend from 75 to 80% of the race time just below the LT, with the balance at or slightly above this point. Typical training runs to accomplish this are:

• Endurance runs of from 30 to 60 minutes at 10 to 20 BPM (beats per minute) below the LT.
• Moderate tempo runs of from 10 to 25 minutes at just below the LT.
• Lactate tolerance intervals of from 60 to 180 seconds at LT + 5 BPM with 30 to 60 second jog recovery between intervals

10,000 METERS

In a hard 10,000 the athlete may spend as much as 10% of the race at or above the LT, with the balance slightly below. Typical training runs:

• Endurance runs of from 45 to 90 minutes at 10 to 20 BPM below the LT.
• Moderate tempo runs of from 20 to 40 minutes at just below the LT.
• LT intervals of from five to seven minutes, run at the LT with a 2 to 3 minute jog recovery between.

MARATHON/ULTRA DISTANCE

Marathoners/ultra distance runners seldom exceed their LT during a race. Typical training runs:

• Endurance runs of from 1 1/2 to 3 hours at 10 to 20 BPM below the LT.
• Moderate tempo runs of from 30 to 60 minutes at just below the LT.

RECOVERY RUNS

Recovery run days need to be in the training plan. A training session where considerable time is spent close to or above the LT is hard on the body, so it is important that the following day should be either an off day or an easy recovery run day.

• Easy recovery runs of from 30 to 45 minutes at 25 to 35 BPM below the LT.

CARDIOVASCULAR DRIFT

Often, after having run from 45 to 60 minutes, there will be a noticeable increase (5 +/- BPM) in pulse rate with no increase in perceived or actual effort. This is a normal, natural phenomenon called "cardiovascular drift."

TRACKING THE LT WHILE RUNNING

Many experienced runners have found the LT effort level through trial and error. They know the feeling and the pace. However, a number of factors such as weather conditions, terrain and fatigue will have an impact on this "feeling", making this a less than reliable method for tracking the LT in training and racing.

LT AND BREATHING

The rate of breathing is determined by the need for oxygen. When running at an effort level where the breathing rate is three strides per breath, the pulse rate is usually well below the LT. As the effort level increases the strides per breath decreases. For a "moderate tempo" run, the breathing rate will usually be at two strides for both the inhale and exhale. This should put the body just below the LT.

At a one stride per inhale, two strides per exhale, the body should be at or just above the LT. At the one stride per inhale and one per exhale, the body is going well above the LT and approaching maximum effort.

LT AND THE "TALK TEST"

When running at a "recovery" pace that is well below the LT, it is easy to carry on a conversation with a companion runner. As the effort approaches the LT, conversations are not possible, only one or two words can be gotten out. When at or above the LT, the runner will not even want to think about talking.

PULSE MONITORS

The ability to continuously monitor pulse and effort is critical when running hilly courses. When racing, the effort level must be maintained to prevent unnecessary slowdowns or exceeding the LT. A "moderate" uphill will require about 35% more effort when maintaining the same race pace. Conversely, the downhill will require about 25% less effort at the same speed. A pulse monitor will allow the runner to adjust effort according to the terrain.

There are pulse monitors available from different manufacturers and the pricing is fairly competitive. They are worth the investment.

Cardiovascular physiology is the key role player in transporting oxygen and nutrients to the muscle system and in the removal of waste products (lactate, carbon dioxide, etc.) from the body.

Pulse rate coupled with stroke volume (amount of blood pumped per heartbeat) are the critical numbers in blood transport. Through proper training the senior/masters athlete can increase both of these numbers.

The heart is a big muscle so the increased strength of this muscle will cause an increase in the stroke volume. Stroke volume increases as the pulse rate increases until nearing the LT. At a point just below the LT, the stroke volume will become constant. In "cardiovascular drift", there is a slight decrease in stroke volume that causes the increase in pulse rate. Female athletes normally have a lower stroke volume than their male counterparts.

Maximum pulse rate is somewhat variable and declines with age. A sedentary individual will usually have a maximum pulse rate in the range of 220 minus the age of the individual. In a well-conditioned athlete this changes to the rage of 210 minus half of the age of the individual.

As with the other muscle groups used while running, the heart will respond to increased workloads. The SAID principle does apply here as well. These increases should be gradual, controlled and monitored. After four to six weeks of a specific training regimen, the body will have received most of the benefits from that training, so either the volume or the intensity of the workout should be increased.

STROKE VOLUME AND DEHYDRATION

As the blood thickens, it requires more force to pump it, thus decreasing the stroke volume. This is what happens as the body becomes dehydrated. To keep the cardiovascular system performing at an optimum level, it must be kept well hydrated. In any race, copious amounts of water should be consumed before and after the race. When the length gets to more than 30 minutes in length, water should be taken during the competition.