How do you measure intensity? So many coaches use so many different methods, power, Heart Rate (HR), three zones, five zones, seven zones?? I’ve been planning a series of weekly articles for over a year now, looking at what different coaches prescribe (or used to prescribe) and why. This is the third article in the series, using Jack Daniels’ Running Formula as the primary reference.
The previous article can be read here.
Dr Jack Daniels is an exercise physiologist and running coach who has coached numerous Olympic athletes and has been named the Worlds Best Coach by Runner’s World magazine. As well as being a two time Olympic medalist in his own right in both 1956 in Melbourne and 1960 in Rome.
Jack Daniel uses five pace or Heart Rate (HR) zones being the equivalent of each other:
| % VO2max Pace | % max HR | Description | |
| E (easy) / L (long) | 59 – 74% | 65 – 79% | Builds resistance to injury, strengthens the heart muscle, improves delivery of blood, promotes some useful characteristics of the muscle fibres. |
| M (marathon pace) | 75 – 84% | 80 – 90% | Adjust to a specific marathon pace, physiological benefits not too dissimilar to L. |
| T (threshold pace) | 83 – 88% | 88 – 92% | Comfortably hard. Allows the body to improve its ability to clear blood lactate. |
| I (interval pace) | 95 – 100% | 98 – 100% | Maximising VO2max. |
| R (repetition pace) | > 100% | n/a | To improve anaerobic power, speed and economy of running. |
Easy Running (E) / Long Running (L)
There are several benefits to running at this lower intensity. One of the key advantages is that you build up a certain degree of resistance to injury. At this intensity you build a base of fitness.
At this easy effort heart muscle gets developed because this is when it needs to beat with most force. As your effort goes up there is less time between beats for the heart chamber to fill with blood, because there is less blood to pump the contraction doesn’t need to be so forceful compared to lower intensities where there is more blood in the heart chambers to pump.
Another benefit at this intensity is that there is an increase in vascularisation – an increase in the amount of capillaries. Capillaries are the smallest blood vessels through which oxygen diffuses directly into the working muscles. Running at this lower intensity generates the changes in the muscle fibres that allows the muscles to accept more oxygen and convert more fuel into energy in a given period of time.
Jack Daniels’ prescribes Easy (E) and Long (L) runs at the same intensity, the difference being the duration or distance of a Long (L) run. What is a Long (L) run for one athlete might be an Easy (E) run for a more accomplished runner.
Unless training for an ultra-marathon event Jack Daniels does not recommend Running longer than 2:30hrs due to the amount of recovery time required after a run of longer duration.
Marathon- Pace (M) Running
As the name implies, Marathon-Pace (M) running is training at your projected marathon race pace.
The purpose of training at this pace is is to develop the mental confidence at race pace. You are encouraged to practice drinking, simulating a race.
Physiologically there is not much difference to training stimuli occurring within the body compared to Easy (E) or Long (L) paced running. These sessions burn through a bit more fuel in the form of carbohydrate than an Easy (E) run of the same duration. This will help to teach the body to conserve stored muscle glycogen and rely a little more on fat metabolism.
For athletes not running a marathon, this pace can develop the confidence that they can handle a fairly prolonged run at something a little faster than Easy (E) paced runs.
Att his pace Jack Daniels does not recommend running at this pace longer than 1:50hr in a given session (assuming there is no running at Threshold (T) pace within the workout), and that the total time of running at Marathon-Pace (M) each week is is less than 20% of weekly mileage.
Threshold (T) Training
A run at Threshold (T) pace is comfortably hard. However the pace is still manageable for a fairly long time (certainly 20 to 30 minutes). When peaked and rested, you will be able to maintain this pace for about an hour. This is the pace for elite runners running a half marathon, or more recreational runners running a 10km.
The paced runs allow your body to improve it’s ability to remove blood lactate, keeping it below a manageable level.
Threshold (T) runs teach your body to deal with a slightly more demanding pace (compared to Easy (E) or Marathon (M) paced runs) for a prolonged period of time. They improve the speed you can keep up for a relatively long period of time.
Jack Daniels recommends two different variations of Threshold (T) runs. he refers to them as Tempo* or Cruise Intervals.
- Tempo Runs: are steady run at Threshold (T) pace lasting about 20 minutes in duration. These are better a building confidence that you can maintain a higher pace for a longer period of time.
- Cruise Intervals: are a series of repetitions run at Threshold (T) pace with a short rest break between the reps. These allow you to get a longer duration of time accumulated at Threshold (T) pace.
Jack Daniels recommends that a workout does not include more than 10% of the weekly mileage at Threshold (T) pace. However for any runner who can handle 20-minutes at Threshold (T) pace, then a minimum of 30-minutes at Threshold (T) pace can be done as cruise intervals.
* Be aware that the term Tempo can mean different things to different athletes or coaches. This is how Jack Daniels uses the term.
Interval (I) Training
Jack Daniels’ describes Interval (I) training with a focus on intensity (and avoiding the obvious fact that the run is broken into various intervals). The purpose of Interval (I) paced running is to maximise aerobic power (V02 max) and maximum Heart Rate (HR). The best way to improve any bodily function is to stress it. For his definition of Interval (I) pace running the intensity needs to be at or very close to V02 max and the work to rest ratio needs to optimise that purpose.
Studies have shown that people can tolerate about 11-minutes at V02 max. Clearly it won’t be a fun workout to go run at V02 max for 11 minutes!!! Also, from complete recovery it also takes between 90 to 120 seconds to build up to a pace that elicits V02 max. For these reasons Jack Daniels’ recommends intervals are between three and five minutes in duration.
By not allowing too long of a recovery between runs V02 will not have recovered completely and the next bout of hard running will reach max in a shorter period of time. This i an important consideration when using intervals shorter than 2 or 3 minutes.
Jack Daniels recommends that a workout does not include more than 8% of the weekly mileage at Interval (I) pace.
Repetition (R) Training
Interval (I) training was to improve aerobic power, the purpose of Repetition (R) training is to improve anaerobic power, speed and economy.
It isn’t rocket science, but if you want to improve your speed, you have to practice running fairly fast. In order to run fairly fast you have to be recovered well enough to actually run fast and with good technique. To ensure this happens, the Rest Interval (RI) should be two to three times the duration (not distance) of the repetition. Alternatively you can jog the same distance as the repetition.
No more than 5% of your weekly mileage should be done at Repetition (R) pace during any given workout. The duration of any Repetition (R) paced bout of running should not exceed 2 minutes.
Here is how I manage Intensity for running:
Train for your next race with the man who has been called “the world’s best running coach.” With more than 55 years of experience, Jack Daniels is a legendary figure in the running community. Named the National Coach of the Year by the NCAA and honored as the Division III Women’s Cross Country Coach of the Century, Daniels has mentored some of the greatest names in running, including Jim Ryun, Ken Martin, Jerry Lawson, Alicia Shay, Peter Gilmore, Magdalena Lewy-Boulet, and Janet Cherobon-Bawcom. In Daniels’ Running Formula, he has shared training advice with hundreds of thousands of runners. Now in this updated—and definitive—fourth edition, he again refines his methods and strategies to help you run faster and stronger.
Building upon his revolutionary VDOT system, Daniels incorporates new insights gained from studying participants in his unique Run SMART Project. You’ll be guided through the components that make the training formula work and then learn different types of training—including treadmill training, fitness training, and training at altitude or in other challenging environments—along with age-related modifications for runners from ages 6 to 80.
Everything comes together with expert advice on event-specific training ranging—for runs ranging from 800 meters to ultradistance events and triathlons. You will find advice on setting up your own seasonal plan, or you can follow one of Daniels’ 31 proven training plans and workouts. You’ll even find four fitness running plans, from novice level to elite level, to get in shape or regain conditioning after injury.
Join the thousands of runners who have relied on Jack Daniels to help them reach their peak running performance. Using the programs outlined in Daniels’ Running Formula, you too can achieve the results you seek every time you train and race.