Lots Of Volume Needed

A nice place to log some serious mileage

Previously I wrote that high mileage alone may not enough for you to run fast. Just because Sebastian Sawe clocked over 240 km a week leading to his sub-2 hour marathon does not mean you too have to clock huge distances to run fast. 

So this post is for serious runners. For runners who want and can log long distances. Runners who want to run fast and are prepared to spend lots of time running. The recommendations will not help weekend warriors who just want to complete a race or fitness influencers to quote this to their followers.

Here is what a comprehensive analysis of the training intensity distribution (TID) across runners from different performance levels looks like. Researchers looked at different training sessions from 16 weeks before 151,813 marathons (yes you read correctly), done by 119,452 runners.

TID was measured using a 3 zone approach (Z1, Z2 and Z3) where critical speed is defined the boundary between Z2 and Z3. Note that this IS different from the Zone 1-5 runners talk about. The Zone 2 most runners talk about is Z1 here and Z3 here is Zone 5 on that scale.

The transition between Z1 and Z2 was assumed to occur at 82.3 percent of critical speed. Critical speed is the maximum running speed you can maintain for 30 to 60 minutes without fatiguing rapidly. It is strongly correlated to your lactate threshold.The training characteristics and TID were reported based on the runners' marathon finish time.

Results show that training mileage was 45.1 ± 26.4 km each week. The fastest runners in the study group (marathon finishing time between 120-150 mins) ran greater than 3 times more volume than slower runners.They did not run fast often.

The amount of time spent training in Z2 and Z3 remained relatively stable across all performance levels, but the proportion of training time spent in  was progressively higher in faster runners.

More than 80 percent of the runners with faster marathon times had a pyramidal approach where the volume of training (mileage) decreases as intensity increases. Visually it forms a pyramid pictured below. A big base of easy Z1 running, a smaller middle section of moderate effort and a tiny peak of high intensity work. 

With regards to total mileage that the faster runners covered, the more time they spent in Z1 (really easy pace), the faster their marathon finish time (p < 0.01 - highly siginificant statistical finding, less than 1 percent chance this happened by coincidence). Moreover, R² ≥ 0.9, meaning over 90 percent of the variance in marathon finish times can be explained by looking at how much total volume the runner did and how much of it was in Z1.

The study also found that the more time a runner spent training at Z2 or Z3 intensities, the slower their marathon finish time. p < 0.01 and R² ≥ 0.85, at least 85 percent of the variance in slower finish times can be predicted by an over reliance on Z2 and Z3 training.

Focusing too much on hard and moderate efforts usually backfires. Why? Running too 'fast' on easy days and not hard enough on hard days means you are in the "grey zone". Not easy enough to get the aerobic adaptations needed and not hard enough to get the benefits of the high quality intervals.

Spending too much time in Z2 (moderately hard) causes higher fatigue levels without the beneficial effects of Z1 nor the high end fitness gains of Z3. 

The fastest runners in this study achieved their better times by increasing training volume mainly in Z1. They also ran less when they incorporated high intensity runs to allow for recovery. 

Is that true for all distances? What about a 5km or 10 km race? Will you still need to run lots of easy Z1 miles. If you want to simply finish the race, no. But if you consider that even a mile race of 5 km race is predominantly aerobic (pictured above) then you will understand why a large volume is needed to build a large base. 

Slower means more sustainable over time, you will not get injured so easily and hence more adaptation over time. That's how you will get stronger. 

Find more ways to increase your training volume with long easy runs. True aerobic developmnent is only possible from accumulating volume.  It allows you to recover and handle the key sessions. You cannot HIIT your way to the top. If you cannot get your hours in then it would be a lot more difficult to run faster.

Reference

Muniz-Pumares D, Hunter B, Meyler S et al (2025). The Training Insity Distribution Of Marathon Runners Across Performance Levels. Sports Med 55: 1023-1035. DOI: 10.1007/s40279-024-02137-7

Sub 2 Hour Marathon

Back in 2017, renowned sports scientist Dr Ross Tucker wrote that a sub 2 hour marathon was unlikely to occur for generations. Then Nike introduced the Breaking 2 project which resulted in Eliud Kipchoge running under 2 hours albeit in a paced setting, not in an official race. 

The 2 hour barrier was finally broken last week at the London marathon when winner Sabastian Sawe and runners-up Yomif Kejelcha achieved the breakthrough, the latter running only his first marathon.

The podium

Sawe beat the previous world record by 65 seconds, finishing in 1:59:30 hrs. He ran an amazing negative split, 60:29 for the first half and the next half in 59:01 min. Kejelcha finished 2nd in 1:59:41 hours. The race was so fast that third place finisher Jacob Kiplimo also broke the previous world record (set in 2023) by 7 seconds. He clocked 2:00:28 hrs.

What lead to the breakthrough? Perhaps due to a "perfect storm" or convergence of many of the following factors. 

Sawe's team said he was running in excess of 200 km a week in the 6 weeks leading up to London, with a maximum of 241 km (150 miles). The volume of his training runs is likely an important factor for him to break 2 hours. Not many elite runners can tolerate that sort of volume, especially when most of it is done at low intensity (or Zone 1). High training volume done at relatively low intensity (Zone 1) is associated in faster marathon performances (Muniz-Pumarez et al, 2024).

Sawe's 5 km splits from 30 km onwards were superb. 30-35 km : 13:54 min, 35-40 km : 13:42 min. His final 2.2 km was 5:51 min. His 24th mile was 4:12 min - the fastest single mile ever run in a marathon. As the finishing line beckoned, he was still accelerating. No way he could have done this if he was not fueling well.

Sawe's nutrition was exceptional. I'm not plugging names here, in fact I've not even tried their products, but Sawe is a Maurten athlete. Elite athletes train their gut take up to 120 grams of carbs while competing without GI distress. The previous recommendation was 60 grams per hour previously. Sawe's reported intake was 115 grams an hour. Maurten's research team was with Sawe in Kenya for 32 days across 6 trips between last year and this April to train his gut to absorb that amount. 

Please note that 120 grams of carbs are NOT recommended for the recreational athlete. That is probably why cycling races and marathons are getting faster since there is no depletion in carbohydrate levels.

Sawe also used sodium bicarbonate (also from Maurten) to buffer his lactic acid build up during the race. He took the sodium bicarbonate early since it peaks in the bloodstream  roughly 60-90 minutes after ingestion so the timing of 2 + hours before the race would put peak buffering capacity at the start.

What about his shoes? Adidas says those were the fastest and lightest super shoes ever made. Actually, Adidas had a great day as 4 of the top 5 men were wearing the same Adizero Adios Pro Evo 3. It weighs 97 grams (for men's size 9), 30 percent lighter than its predecessor with a stack height of 39 mm (below the 40 mm limit by World Athletics). 

The Lightstrike Pro foam used is 50 percent lighter than the previous version, along with the carbon plate. Research suggests that the foam and carbon plate can affect the "spring like" bounce of the body as the foot strikes and leaves the ground. The shoes help to store and release energy and acts like the runner is pushing off a springboard so less energy is needed for the run.

London is considered a relatively fast course (though not as fast as Berlin) and the weather conditions was between 13-17 degrees Celsius, close to ideal.

There you have it, exceptional athlete physiology, high mileage training without injury, efficient biomechanics, super shoes , optimized fueling and favorable conditions. The recipe for success for running marathons.

Reference

Muniz-Pumares D, Hunter B, Meyler S et al (2025). The Training Intensity Distribution Of Marathon Runnersd Across Performance Levels. Sports Med. 55: 1023-1035. DOI: 10.1007/s40279-024-02137-7

What Is The Right Way To Train?

ST 040226

Controversial topic this week everyone. Earlier in the week (4/2/26), there was an article in the Life section of the Straits Times on page C3 with the headline "You can get away with minimum exercise". It was originally published in the New York Times on 150126.

And you often see such headlines in Tik Tok, X or Facebook. When such a study, article, post or reel does well, the exercise scientists, coaches, influencers comment to critique, nitpick or praise the wording, arguing that the study, article, post or reel is being "oversold" or interpreted wrongly.

Are these exercise scientists, coaches, fitness influencers and keyboard warriors just argumentative or is it something else? The above mentioned groups will never see eye to eye. And that is fine since we all learn or at least get entertained by them (pictured above and below).

I think they are disagreeing about different things. "Training" is thought to be the same for everyone. It actually isn't.

When a coach or exercise scientist (or physiologist) talks about training, they are referring to training for sporting performance, or a race. A 40 km cycling time trial, a marathon, a 10 km race or a Hyrox competition. There is an objective measure, or the outcome has a clear definition of who is first or second.

When a fitness or health influencer talks about training, they are not talking about training for a race or competition, they are referring to wellness, losing weight, longevity, reducing falls and perhaps looking or feeling good. It does not require one to revolve their whole life around exercise, training and competing.

Is exercise just exercise? Both their perspectives overlap. Health focused training can improve performance. Training for performance improves health, until you overtrain, which then can be harmful.

However, the time constraints and success metrics are totally different. If one does not say which you are referring to (health or performance), then that's when you will have both sides disagreeing passionately when they are in fact talking about 2 different things.

The exercise physiologists and coaches will treat the study as giving instructions for how to train like an athlete. The fitness influencers will translate it into something the average person can understand and apply. 

Same data, different interpretation.

Remember my article about Zone 2 training? The endurance coaches and exercise physiologists will get their athletes to train easy mostly in Zone 1 or 2. Build the aerobic base. Then 10-15 percent of high intensity work. Are they correct? Definitely. If their athletes are training in excess of 20 plus hours a week, they cannot go hard all the time. They will get burned out and most likely injured.

The fitness influencers are advising humans and mere mortals who are maybe exercising just once or twice a week, definitely under 5 hours total. They are not deciding whether to train at altitude or to periodize their training. They are probably trying to find time and convince themselves to exercise after a long day at work. 

So when they read or watch online reels about exercising mostly at Zone 2, they will think they need to devote a LOT of time exercising at low intensity.

For the athlete, that's super sensible. For the mere mortal and weekend warrior with limited time and motivation, it is impractical or even impossible.  Not because Zone 2 is bad. For Zone 2 to work, you have to accumulate hours. To have super powers, you have to put in the hours.

This is why Zone 2 versus HIIT (high intensity interval training) arguments get so heated. The 2 sides are debating 2 completely different cases but using the SAME lingo and assume that studies on athletes apply to studies on the average population and vice versa.

Studies on interval training, HIIT etc to improve VO2 max are designed to be time efficient. All the research says that if someone has limited time, what is the smallest dose of exercise that gives meaningful results? Or like the picture I posted on top "You can get away with minimum exercise".

If you do not have enough time, you need higher intensity training to provide a stimulus that is large enough to make a difference. This is why the coaches give their 2 cents worth and say that HIIT alone will not prepare you for a marathon.

The coaches are correct, but the fitness influencers were also not getting their readers to race marathons. A study that shows HIIT improves VO2 max does not automatically become a training plan for a marathon even though it is about aerobic fitness. 

Here is what confuses everyone, myself included sometimes. When we take research designed for the elite athletes and try to apply it to the general population and vice versa. Then we act surprised when different groups object for different reasons.

A 6 hour easy ride for a Tour De France rider is simply not normal, realistic, nor repeatable and effective for a weekend cyclist given the time and motivation they have. Remember my 160 km ride to Kukup, it took me almost half a day to recover.

The problem is we cannot communicate on the same wavelength when it comes to exercise. There are disagreements because we keep failing to clarify the context.

So if you are just exercising for general health and do not have plenty of time and motivation, high intensity training will be time efficient for improving your aerobic fitness, metabolic health and help you live longer. Not because easy training is useless, but you are trying to get meaningful adaptation out of limited time.

For athletes and those who have time to accumulate volume, Zone 2 exercise is sustainable, easier to recover from and foundational. It becomes really powerful as Zone 2's super power is accumulation. It improves durability, helps support overall training volume and makes you better at endurance and also to handle the high intensity training when you need to.

Coaches can tell you how their athletes build great endurance while not being helpful for the average Joe or Jane whose main goal is getting started. 

Fitness or health influencers can be correct about time efficient fitness strategies while being totally inadequate with regards to an athlete's performance in a specific sport.

An exercise physiologist and sports scientist can be super accurate about what a study shows but missing how the lay person will interpret it in the real world.

I hope this explains things better so we know that there is no one 'best' way to achieve fitness, health or performance goals.

Race Pace Versus Heart Rate Variability Guided Training

Picture taken from Flowly

A patient came in this week after he raced the Tokyo marathon last weekend. He was not happy as he started cramping in his hamstrings after 'only' 5 km.

I asked about how his training went. He told me he did 4 runs a week, all on a treadmill, mostly easy runs. His longest run was by time, 2:55 hrs (which he thought was equivalent to about 20 km).

He did all his runs with a heart rate monitor, training at "Zone 2" mostly and followed recovery metrics like heart rate variability *(HRV). Zone 2 training is low intensity exercise that involves training at 60-70 percent of maximum heart rate. He did not do any interval training nor any race pace training.

I discussed with him how he can do better since he will be running the Chicago marathon on October 12th this year. He really wants a improvement after his self described disastrous Tokyo race. I shared with him a study that tested 3 different approaches of training (Ranieri et al, 2025).The researchers split the runners into 3 different groups for 6 weeks. 

First, a heart rate based training group where training is prescribed by heart rate zones. Next a race pace training group in which training is prescribed running at percentages of race pace. Lastly a HRV guided training group. The HRV training group did training prescribed by heart rate zones but this was adjusted daily based on HRV readings. Hence their intensity was based on how well they recovered. 

All the runners did lab tests before and after the study. V02 max, running economy, ventilatory thresholds and other key endurance metrics. Participants were assessed by a 7 km time trial after the training period.

Results? Race pace training was the most reliable for improving race performance. Every single runner in that group went faster in the 7 km time trial with an average improvement of 3.8 percent. The runners also had gains in fat loss and maximal aerobic speed. The heart rate training group improved their ventilatory threshold readings but this did not lead to V02 max or time trial improvement. It did not deliver clear performance advantages over race pace training.

The HRV training group led to bigger physiological improvements. They had significant increases in ventilatory thresholds and V02 max, but this did not translate as well to race performance. Some participants also put on weight (fat mass) perhaps due to more frequent easy training days.

The authors concluded that race pace training had the least variablilty in response, meaning it worked reliably across runners. HRV based training showed individual differences, some saw gains, others did not. This is not surprising since HRV itself is highly variable.

I suggested to my patient that he needed to do some race pace training if he wanted to achieve his target timing. He can take his target finishing time and calculate how fast he needs to do his 1 km, 5 km or even 400m repeats. This teaches his body to gauge the pace he needs to run and not go too fast especially at the start. It will also prepare his body for the demands of race day.

I also suggested running more outdoors rather than solely indoors on a treadmill since the treadmill is softer and will not mimic the road conditions that he races on. Specificity is key. The gym environment is temperature controlled unlike outdoors. So if the race location is hotter and more humid then he will be less able to handle it.

Takeaway message? The best approach is not to train solely on a single approach. It is best to know when to use each approach. For example, you cannot train exclusively by race pace. The body will not be able to handle the load, one would likely get injured. 

Heart rate based training can definitely be used but should not be relied on exclusively too. It will improve physiological markers and your lab based testing (V02 max, lactate threshold), but may not result in faster race timings. 

HRV is a useful tool for monitoring stress and how well your body is recovering. Many professional athletes use it. However this study raises an important question of whether better physiological markers lead to better performance.

If you're looking for a fool proof way to inprove your race times, this study suggest that training at your race pace sould be a part of your training routine.

Reference

Ranieri LE, Casada A, Martin D et al (2025). Performance And Physiological Effects Of Race Paced-Based Versus Heart Rate Variability-Guided Training Prescription In Runners. Med Sci Sp Ex. DOI: 10.1249/MSS.0000000000003671

*Heart rate variability (HRV) is a measure of how much time passes between each heart beat. It is better to have a higher than lower number. It is physiological measurement that is used to understand how your body is coping with life and environmental changes. A low HRV may suggest that your body is not rested, less resilient  and may not handle changing situations. You can measure HRV with a smart watch, fitness tracker etc.