Aerobic Endurance Training

There are several different types of aerobic endurance training - each with a different, specific outcome and suitable for different events and sports.

The duration, frequency and intensity of sessions varies with each form of training leading to different physiological adaptations within the body. The table below summarizes the main types of aerobic endurance training and suggested parameters:

Long Slow Distance Training

As you would expect this type of training is typical of a long distance runner. Intensity is usually less than 70% VO2max, or equivalent to about 80% maximum heart rate. Duration should be near to race distance or at least 30 minutes to 2 hours long (1). Intensity for long, slow distance endurance training is often gauged using the "talk" test whereby the athlete can hold a conversation without being too winded.

Adaptations to this form of aerobic endurance training include improved cardiovascular and thermoregulatory function, improved mitochondrial energy production, increased oxidative capacity of skeletal muscle and increased utilization as fat for fuel (which spares muscle glycogen) (2,3,4,5,6,7). Anaerobic or lactate threshold is also likely to improve with a body better able to remove lactate.

Because long distance training is low intensity (lower than competition) too great a reliance on this form of endurance running in the athlete's training program can be disadvantageous. Here is a sample training program for a marathon runner:

Sample Half Marathon Training Plan
Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Rest	Fartlek Run (45 min)	Long Slow Distance Run (60 min)	Interval Training (45 min)	Pace/Tempo Run (60 min)	Repetition Run (45 min)	Long Slow Distance Run (120 min)

Notice how the two long distance runs are split up with plenty of rest between? Only one run per week that approaches half marathon distance. The other types of training are covered below.

Pace/Tempo Training      

Also referred to as lactate threshold training, pace/tempo training is designed to improve energy production from both aerobic and anaerobic energy pathways. Intensity is slightly higher than race pace and corresponds to thelactate threshold. Duration is usually 20-30 minutes at a steady pace. lactate threshold

Tempo/pace training can also be performed intermittently or in intervals (1). Intensity is the same as steady state tempo/pace training except the session consists of a series of shorter bouts with brief recovery periods. It is important to keep intensity at or slightly higher than competition pace for either type of pace/tempo training. Progression should be in the form of increased duration rather than a faster running/cycling/swimming ect. 

Interval Training

Interval training allows the athlete to work close to their aerobic limit (VO2max) for a longer duration compared to a continuous type session. Short bouts of 3-5 minutes at an intensity close to VO2max are interspersed by periods of active recovery. Work to rest ratio should be 1:1 so a 3 minute run should be followed by 3 minutes of rest (8).

Because this type of aerobic endurance training is very demanding, sessions should be limited both in duration and in frequency each week. Duration is usually 30-45 minutes and frequency is one or two sessions per week, with ample rest days between. Below is a sample program for a 10k runner:

Sample 10K Training Plan
Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Rest	10 x 0.5km	10km run (easy)	Long Slow Distance Run (45 min)	5 x 1km	Long Slow Distance Run (45 min)	Fartlek Run (45 min)

Taking the time for each 0.5km interval, allocate the same amount of time for the rest periods between. Rest should be in the form of active recovery such as brisk walking or very light jogging. 

Repetition Training

This is the most intense form of aerobic endurance training. Performed at a pace greater than VO2max it places a high demand on the anaerobic energy systems. Work intervals are usually only 60-90 seconds separated by rest intervals of 5 minutes or more. Typically work to rest ratio is 1:5 (8). Repetition training helps to improve running speed, running economy and builds a greater tolerance to lactic acid. Endurance athletes often use repetition training to help in the final kick of a race. Due to the high intensity nature, only one session per week is required.

Fartlek Training

Fartlek training combines some or all of the above aerobic endurance training techniques. A long slow run/cycle (at about 70% VO2max) form the foundation of the session and is combined with short bursts of higher intensity work. There is no set format for a Fartlek session although there are some standard sessions that have been developed by coaches over the years. Fartlek endurance training will improve VO2max, exercise economy and lactate threshold. It also adds a nice change of pace to the more monotonous steady-state training. The table below outlines a sample program for an amateur Cross Country Runner:

Sample Cross Country Training Plan
Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Rest	Long slow distance run (60 min)	Fartlek run (45 min)	Pace/Tempo Run (25 min)	Long Slow Distance Run (45 min)	25 min Long Slow Distance Run	Race Day

There are literally dozens of fartlek sessions that can be adopted into an aerobic endurance training program. 

References

1) Daniels J. Training Distance Runners - a Primer. Gatorade Sports Sci. Exch. 1:1-5. 1989
2) Costill DL, Fink WJ, Pollock ML. Muscle fibre composition and enzyme activities of elite distance runners. Med Sci Sports. 1979,8:96-102
3) Costill DL, Thomas R, Robergs RA, Pascoe D, Lambert C, Barr S, Fink WJ. Adaptations to swimming training: influence of training volume. Med Sci Sports Exerc. 1991 Mar;23(3):371-7
4) Dudley GA, Abraham WM, Terjung RL. Influence of exercise intensity and duration on biochemical adaptations in skeletal muscle. J Appl Physiol. 1982 Oct;53(4):844-50
5) Foster C, Hector LL, Welsh R, Schrager M, Green MA, Snyder AC. Effects of specific versus cross-training on running performance. Eur J Appl Physiol Occup Physiol. 1995;70(4):367-72
6) Holloszy JO, Coyle EF. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J Appl Physiol. 1984 Apr;56(4):831-8
7) Hawley JA. Adaptations of skeletal muscle to prolonged, intense endurance training. Clin Exp Pharmacol Physiol. 2002 Mar;29(3):218-22
8) Baechle TR and Earle RW. (2000) Essentials of Strength Training and Conditioning: 2nd Edition. Champaign, IL: Human Kinetics