Daniels for IM

“Ignorant people see life as either existence or non-existence, but wise men see it beyond both existence and non-existence to something that transcends them both; this is an observation of the Middle Way.”

-Seneca

From the times of Zatopek and Lydiard, there have remained 2 basic schools to endurance training – the ‘far before fast’ school (Lydiard, Viren, Seiko etc) and the ‘fast before far’ school (Zatopek, Peters, Pirie etc).

Advocates of the latter school have often claimed that the athlete who is most successful at the shorter distances will ultimately prove most successful at the longer distances. With the recent marathon success of athletes such as Haile Gebresellassie (an athlete with a sub 3:50mile best), it is hard to argue with this perspective.

One modern day exponent of this approach is the man pictured above, the ‘Godfather’ of modern day distance running, Mr. Jack Daniels. In fact, Daniels has gone so far as to draw up mathematical predictive tables that estimate what an athlete will run for the longer distances based on what they are able to do over the short. In the triathlon world, a similar approach has been used by Hunter Kemper’s coach, Mr George Dallam.

A number of somewhat less astute Ironman coaches have proposed a similar relationship for Ironman racing e.g. ‘give me an athletes 40K time & I’ll tell you what their IM split will be’. The reason that this approach is far less accurate/predictive for Ironman is that it crosses physiological systems. Let me elaborate by presenting a table from Australian physiologist John Hawley, that shows the ergogenesis (source of energy contribution) of different events.



You can clearly see that for the performance durations that Daniels tables are looking to predict, i.e. 4min to 2hr, there is a very high contribution given by one energy system – the aerobic glycolytic system, with 81-92% of energy demands of a mile (a 4 minute event) to a half marathon (a 1 hour event) made up from this energy system.

However, given the fact that success in Ironman events (and for most folks, Half Ironman events) is more dependent on aerobic lipolytic power (i.e. ‘fat burning’ than it is on aerobic glycolytic power, using durations that represent close to 100% glycolytic contribution as predictors is subject to a good deal of error.

Rather than relying on performance in aerobic glycolytic events exclusively, a better prediction can be gained by looking at this number along with a representative measure of the athletes aerobic lipolytic power, i.e. training performance over long sessions and over the course of the training week. In this way, the Daniels tables can be modified to better represent equivalent performance standards for IM.

In studying data from a number of ultra runners and ultra-distance triathletes, I have found that the relationship between short distance performance and Ironman performance is not a natural logarithmic function as postulated by the Daniels model, but rather a curvilinear function with a modified ‘tail’ due to the increased contribution from alternative energy production mechanisms, i.e. aerobic lipolysis, or ‘fat burning’.

In the Ironman world, knowing one point on the curve, as Daniels suggests is not sufficient to predict performance. Even knowing 2 points on the curve, as Dallam suggests is insufficient. While the power of the athletes aerobic glycolytic energy system certainly plays a part, to create an accurate model of Ironman performance, it is important to know how the athlete performs not just in the glycolytic energy systems, but also the lipolytic.

This difference in the nature of the curve for a large data sample of Ultra distance athletes vs. Long distance athletes is shown below.



The gap between the red line and the blue line is indicative of the extra fat burning capacity required by athletes who participate in ultra-distance events.

In a practical sense, this information can be used to modify Daniels’ original running formula to ensure that appropriate attention is being given to both the aerobic glycolytic and aerobic lipolytic energy systems and that the Ironman athletes development is progressing in a ‘balanced’ way.

In terms of periodization and actual programming, this table can be used as a ‘checklist’ where the athlete achieves each of the performance standards in each fitness row before moving on to the next fitness level. To ensure that the athlete has an appropriate level of ‘far’ and ‘fast’ at any point in his/her training development.

So, without further ado….

Here is a scaled down version of Daniels original table:

Daniels Original Tables









And a modified version in accordance with ultra-distance athletes relative strength over the longer durations of the curve.

Daniels for IM









The ‘tipping point’ between the two tables occurs in between the Threshold and Marathon Pace categories, i.e. the point where fat oxidation begins to make a significant contribution to the energy demands of the event.

In addition to the practical applicability of these tables, some sports scientists have suggested that the ergogenesis table listed above can be used as a good starting point to determining % weekly breakdown during the specific preparation period (Bompa, 1998). In other words, for an event that is 50% lipolytic and 50% glycolytic, half of the weekly sessions should be at or slower than Half IM effort, while the remaining 50% should be in the glycolytic range (5K pace to Threshold efforts). This approach makes logical sense and has a good deal of ‘real world’ support from athletes like Seb Coe, whose 800m (~2min duration) specific training was broken down into 60% aerobic/40% anaerobic sessions (Coe, 1991)

In a previous blog (Big A’s Dojo), I had presented some general recommendations as to appropriate levels of performance for the various physiological systems that indicate a generally balanced development. For the Ultra-distance athlete, these can be (slightly) modified as follows in accordance with the above tables.

Yellow Belt (VDOT 45-50):

- A 30mi (flat) run week in less than 4:36

- The ability to execute a functional strength routine with good form and optimal range of motion
- The ability to do 6x200m strides (pain free) in <50s/200

(Total Glycolytic=0% of weekly total)

Blue Belt (VDOT 50-55):

- A 40mi (flat) run week in less than 5:24 including:

- A 14mi long run in less than 2hrs

- 6x200m strides in less than 46s/200

- 6x1mi intervals in less than 7:00/mi w/1min rest

(Total Glycolytic = ~15% of weekly total)

Black Belt (VDOT 55-60):

- A 50mi (flat) run week in less than 6:30 including:

- A 20mi long run w/7mi @ MP in less than 2:40

- 6x200m strides in less than 42s/200

- 6x1mi intervals in less than 6:20 w/1min rest

- 4x1200’s @ 9:00 w/a 800 jog in less than 4:30/1200

(Total Glycolytic = ~30% of weekly total)

You will see that the above provides practical recommendations in accordance with appropriate strengths and weaknesses and the ergogenesis of the event(s). For athletes whose race duration is in and around 12hrs, the contribution of energy via glycolysis is negligible and therefore almost ALL training for athletes with a base training pace of >9:00/mile should be focused on improving the athletes lipolytic capacity (slower than marathon pace training).

As athletes get progressively faster and the glycolytic component increases, the need for marathon pace and faster than marathon pace training increases. However, even for speedy athletes or short course specialists, the amount of glycolytic training that the athlete can tolerate is directly affected by their ability to spare glycogen via fat-burning. For that reason, achieving the long duration benchmarks during the early season is always the first priority.

As Peter Coe points out in his landmark book “Better Training for Distance Runners”, these relative performance tables can not only point out relative weaknesses that should be given attention during the specific preparatory phase of training, but they can also provide useful information as to what event the athlete is best suited to. If, after a prolonged period of attention, the athlete still has a hard time hitting the relative performance levels of a balanced Ironman athlete, they may find greater success in events that better fit their natural energetic balance (e.g. short course racing or ultradistance/adventure racing). That is one of the great things about the diversity of sport. If you look hard enough, we all have a particular sport or event that was created for someone (and probably by someone) just like you. The trick is getting to know yourself as an athlete well enough to find it.

Train smart.

AC