How to Get Into Ketosis Fast
The low-carb, high-fat keto diet has been shown to improve body composition and increase endurance performance. But getting into ketosis is difficu...
Updated November 11, 2019
You’re a new runner and would love to run your first marathon. You’re not alone. In 2016, there were over 507,000 marathon finishers, and participation seems to be increasing.
It takes fitness to complete a marathon. Even getting to the starting line requires using science, grit, and training hacks to help you cross the finish line.
Marathon training is a uniquely hard (compared to a half marathon), worthwhile process, with numerous physical benefits. It strengthens and remodels the heart,
Many marathon plans can be as short as 16 - 20 weeks (although we'd recommend a bit longer) and require running a minimum of 3 - 5 times per week. The barriers to entry are small. Can you run six miles continuously? Do you have a few 5k and 10k races under you belt? If so, you’re ready to train for a marathon.
Preparing for the marathon means knowing what to train for and which energy systems to target that you’ll use during the race. A training program must optimize workouts and induce proper amounts of stress to fit the demands of marathon running.
The marathon is ~97.5% aerobic—most energy you produce to fuel the 26.2 miles will come from aerobic energy systems (glycolysis and oxidative phosphorylation to produce ATP). Training your aerobic capacity should be the main focus of training. High-intensity sprints won’t help you in this race. You need a robust engine capable of taking up oxygen and using it to generate energy.
It is estimated that runners can expend anywhere up to ~2,600 calories during a marathon race
Marathon training will focus on optimizing two systems: aerobic energy production and the efficient use of fuel. The ability to delay fatigue is crucial. Studies on endurance athletes over the past decades have indicated that there are key factors of successful endurance athletes: a high aerobic capacity, an ability to run at a higher percent of aerobic capacity for a long time, fast running speed at their lactate threshold (LT), fatigue resistance (muscular endurance), and the ability to use fat as a fuel during endurance exercise.
Before jumping into tempo workouts, higher-intensity threshold runs, and all-important long runs, you need to build a base.
Base-building should be thought of as preconditioning for your muscular and aerobic system, priming it to take on the stress of further training.
The base building period should last about 4 - 12 weeks and compose the beginning of your training period.
Base or foundation training is a staple in endurance training. This period takes place throughout a major portion of the year before endurance athletes transition into higher level speed training. It also helps that athletes respond better to intense training, perhaps by preventing soreness and fatigue during the transition. Before planting the seeds of fitness, you need to lay the fertile soil.
Training emphasis in the base-building phase should be on prolonged, easy-to-moderate-intensity workouts. Runs lasting anywhere from 45 - 60 minutes or more at a pace around 65% - 80% of HR max are the staple during foundation training. This intensity corresponds to heart rate zone 2 - 3. While training in this zone may not boost aerobic capacity or lactate threshold much, it will boost muscle capillary content, mitochondrial capacity, and build up the fatigue resistance needed for upcoming faster and intense training.
As a general rule, mileage during the base-building phase shouldn’t progress more than 10% per week. For example, if you run 40 miles in the first week of this phase, run no more than 44 - 45 the next week. This helps prevent injury and avoid overtraining.
How fast should you run the marathon? How fast should training runs and workouts be? Marathoners must ask these questions before embarking on any training plan; goal race pace will guide the intensity of many workouts.
Finding a marathon goal pace isn’t randomly picking a number. You can estimate a goal time using a previous race, like a 5k or a 10k. This might be sound, physiologically speaking. Plugging a recent time into a race calculator will spit out a projected marathon race finish time. While inexact, this provides an estimate of what’s physiologically possible for you right now.
Once establishing a goal time, determining training pace is easy using an online race calculator or your average mile pace to prescribe workouts. Many runners enjoy using pace to guide their training because numbers are satisfying.
Another option is using HR zones to guide workouts. This method is more “effort based” than using precise pace data, and it may be easier to prescribe workouts. For instance, a majority of your marathon training should be performed in zones 1 - 3 (mostly 2 - 3), corresponding to low to moderate intensity. Successful endurance athletes train about ~80% of their volume in this area. Higher intensity training, zones 4 and 5, will compose the rest of your training. This includes your weekly intervals, tempo runs, and other faster running.
Why use HR instead of pace? It may be easier and less stressful to monitor HR instead of minute-by-minute pace.
Many watches come equipped with HR monitors and will even tell you what zone in which you’re exercising. Specific zones correspond roughly to the specific energy systems employed, so you can hit the right ones during training.
You won’t need much, but speed work is an important component of a marathon training plan. Race-specific workouts should be introduced following your base-building phase. Initially, add in one workout per week and gradually build to 2 - 3 sessions of speed weekly.
A great marathon performance requires running for a long time at a high percentage of aerobic capacity (somewhere close to lactate threshold). A higher ability to run fast at lactate threshold is associated with a better marathon performance.
Threshold (tempo) runs and “cruise intervals” are workouts designed to target lactate threshold. These are less intense than high-intensity interval training, occurring at ~85% of HR max. Tempo runs are effective, requiring less recovery than high-intensity interval training. Just six weeks of training at lactate steady-state increased the time and distance athletes could run at this intensity, increasing their total running time by ~19 minutes and their total distanced covered over 5 kilometers!
For a variation in threshold training, try cruise intervals. These are tempo-paced running bouts (about a mile in distance) separated by brief recovery periods. Start with a two mile warmup, run 5 x 1 mile “cruise intervals” at your tempo pace, with 60 - 90 seconds of recovery between each. Long intervals such as these are particularly effective for improving running economy, another critical factor to endurance performance. Compared to short interval training (SIT), intervals of four minutes with two minutes of rest significantly improve running economy, VO2 max and decreased aerobic demand while running at a submaximal intensity. In essence, the cost of running was reduced.
Marathon speed work is about teaching muscles to run at marathon pace while fatigued. Simulating race conditions during workouts is necessary to adapt to the stress of race day.
Using threshold runs enhances fatigue resistance in Type I fibers and builds robust mitochondria. Train to become an energetic powerhouse.
To finish a marathon, you need to be good at spending a long time on your feet. This type of staying power comes from running, and running long! This also means you shouldn’t be afraid to run slow. Pace on long runs should be easy, conversational.
How far should you run? Complete at least one or two 18 - 20 milers before lining up for a marathon. This distance is sufficient to simulate marathon stress, but not long enough to create a high risk of injury or demand extra recovery time. Following prolonged exercise like a long run, stress markers like creatine kinase, myoglobin, and catecholamines all rise substantially, indicating significant muscle damage.
“Never run a marathon to train for a marathon.” This suggestion may seem paradoxical, but is based on sound rationale. Running a marathon causes structural damage to muscle tissue, leads to an acute stress response, and even causes mitochondrial degeneration.
The optimal duration for a long run: look to make this workout about ~33% of your total weekly mileage. If you’re running ~45 miles per week, this means a long run of about 15 miles or more. Some runners like to do one long effort each week, however, completing a long run on a nine day cycle is also beneficial and may allow for a little extra recovery time between these long efforts.
Don’t try anything new on race day. This axiom applies to nutrition, gear, or anything that could cause a problem during your marathon.
Schedule 2 - 3 long runs during your training schedule as “dress rehearsals.” Wake up and start running at the same time as the race, eat and drink the same foods the night before and the day of, and wear the same clothes and running shoes you plan to sport on the big day. While you can’t control the weather, it might also be great to practice running in different conditions to prepare for the race-day climate. Familiarity is a friend to endurance athletes.
Along with nutrition and gear, you can mix up marathon long runs by practicing race pace during these sessions. If you decide to integrate race-pace work into your long run, make sure this counts as one of your workouts for the week–don’t risk overtraining by adding too much high-intensity work into your week.
An example of this type of workout is called a “surge” long run. These runs train you to run at aerobic threshold (i.e. marathon pace) while fatigued. Run 8 - 10 miles at an easy, comfortable pace. During mile four or five, increase pace to run at ~10k race pace. This small “surge” portion will fatigue your muscle fibers and require a small shift in fuel utilization from fat to more predominantly carbohydrate oxidation. After the surge, complete the remaining part of your long run at an easy pace.
The energy needed to run a marathon comes from two places: carbohydrate stores in muscle and liver (glycogen) and fat stores in muscle and adipose tissue. These stored energy repositories are liberated during oxidative phosphorylation–the energy producing system used mainly during aerobic endurance runs. Energy can also come from outside, from gels and carbohydrate sports drinks. Or you can use a zero carbs, zero sugar ketone ester supplement with natural energy from ketones. It's a novel solution to the problem of marathon fueling.
To maximize training, you need to know how to fuel properly.
As training progresses, mitochondrial volume increases, meaning you can oxidize more carbohydrate and fat during high-intensity performance.
It’s well known that having adequate carbohydrate availability for prolonged submaximal and higher-intensity exercise allows athletes to train hard and maximize their adaptations to exercise.
High carbohydrate availability throughout daily training provides an adequate fuel supply for the muscle and central nervous system to operate properly and prevent fatigue.
A recent training strategy, termed “train low,” may provide an opportunity to enhance your marathon training if used strategically. “Training low” means commencing some exercise sessions with a low muscle glycogen content–meaning, carbohydrate depleted. Exercise completed with low glycogen results in boosted transcription of genes for energy regulation, particularly those associated with fat metabolism.
Periodize carbohydrate availability for easy days or regular endurance sessions. Achieving this is easy. Strategies include running in the morning after an overnight fast, completing a “two-a-day” workout without adequately refueling after the morning session, and drinking water instead of a sports drink during longer runs. The idea is to force the body to utilize fat and upregulate its ability to do so. Research shows fasted exercise works. Just six weeks of endurance training in a fasted state leads to increased oxidative capacity of muscle, better fat breakdown capacity, and prevents a drop in blood glucose during exercise.
On the flip side of the “train low” paradigm, do your marathon-specific speed sessions, tempos, and long runs with proper fuel availability. When it’s important to train hard, carbohydrate intake in the hours prior to exercise should match fuel needs of training enabling a stronger, harder run.
For a higher-intensity session lasting 90 minutes or less, eat something easily digestible with adequate energy (mainly carbohydrates) about 1 - 2 hours before. Avoid foods high in fat, protein and/or fiber–they might upset your GI tract and cause issues such as runner's diarrhea.
Eating something in the pre-exercise window will “top off” fuel stores. You’ll need it. High-intensity exercise around 90% of V02 max relies primarily on carbohydrate oxidation for energy. If you’re able to train harder by having more fuel on board, you’ll promote more muscular and aerobic adaptations to prepare yourself for a faster marathon.
Fueling while running can be tricky. The good news is, any workout under about 90 minutes probably doesn’t require intake of anything other than water. The long run may be the only time you to take in some supplemental or exogenous nutrition. This is also an exercise in finding out what works in terms of nutrition strategies for racing.
Have an 18 - 20 miler planned? You’ll likely be out on the road for around 2 - 3 hours, and performance will benefit from supplemental carbohydrates like a sports drink or energy gel. Runners should consume 60g - 90g of carbohydrates per hour (along with sufficient fluids) to maintain power output and speed and reduce glycogen depletion.
A 2:1 ratio of glucose:fructose has been shown to be optimal for intestinal absorption
Eating post-exercise is important for two reasons: repairing and rebuilding damaged muscle, and replenishing depleted fuel stores. Do both to boost recovery and adaptive capabilities.
Following a run, consume some form of carbohydrate within one hour–this is the period where the highest rate of muscle glycogen storage / resynthesis occurs.
Enhance recovery by consuming carbohydrates along with other macronutrients. For example, cyclists who consumed protein with a carbohydrate drink after a high-intensity 90-minute cycle enhanced muscle protein synthesis; a stimulus for larger, more powerful muscles, after the ride.
The applications of exogenous ketones for endurance performance have also been investigated in this realm. Ingestion of an exogenous ketone, high in the BHB ketone body, along with post-exercise carbohydrates, has been shown to enhance muscle glycogen synthesis after glycogen-depleting exercise.
Hydration–before, during, after workouts and throughout your entire marathon program is important.
Hypohydration (dehydration) of just 3% - 4% can reduce muscular endurance during high-intensity exercise by as much as 10%, and even strength and power by around 2% - 3%.
Improper hydration, especially in the heat, has detrimental effects on the cardiovascular system, metabolism, acid-buffering, and neuromuscular function. The loss of performance may be largely in your brain; hypohydration impairs the ability of the central nervous system to properly recruit motor units needed to contract muscles and run fast and long.
Maintaining a high training output means staying hydrated.
A simple recommendation to prevent over-hydration (and under-hydration) is to drink in proportion to sweat rate. This will prevent water weight loss is excess of 2%, which have been shown to reduce endurance performance, although this number is controversial.
In fact, drinking to thirst might be your best bet, as drinking in excess of sweating rate and persistent over-drinking can in fact be harmful to not only performance but to health.
Runners get injured. The incidence of lower-extremity injuries in runners has been estimated to be anywhere between 19.4% - 79.3%. Marathon runners may be at an increased risk due to high training volume; a long training distance per week is associated with more injuries among distance runners.
But, injury isn’t inevitable. With proper recovery, nutrition, and smart-training, a healthy marathon training block is achievable.
Recover properly from hard workouts by taking a rest day after a high-intensity session (like a hill run) or your weekly long run. Rest can mean a complete off day, or a day where you replace your run with a cross training session. To further reduce risk (and boost workout performance), sandwich your hard days between to easy runs or cross training workouts (like yoga or strength training).
Sleep is also important for recovery–there are no off days to be had here. Aim for 7 - 9 hours of quality sleep per night. While important for recovery of muscular and metabolic homeostasis, sleep also helps prevent sickness. Endurance training compromises immune function, and lack of sleep is a risk factor for infection. Risk of upper respiratory infection (URTI) during training is the highest in athletes who report large amounts of stress and sleep deprivation.
For injury prevention, completing a proper low-intensity warm up with some dynamic exercises prior to running is more beneficial than stretching; which contrary to popular belief has been shown to have no influence on injury risk in runners.
Following the advice of coaches and the wisdom of science is obviously necessary if you want to train right and adapt. However, working hard is just one piece of the pie. A smart, well structured training plan that considers all aspects of your training and recovery is necessary.
Marathon training is a tight-rope walk, a balance between working hard and recovering right, never tilting too far to the side of either.
Even experienced runners don't plan back-to-back hard days; meaning no long run following a tempo, or vice-versa. This won’t give your system enough time to recover and puts you at risk for injury and illness or worse, the potential for overtraining.
It’s generally recommended marathoners do around two speed sessions per week. An additional third supplemental speed workout might be disguised as a “surge” long run, strides, or a moderately-paced distance run
No athlete wants to waste training, but if you veer off of a prescribed pace during a workout–that’s OK. It’s important to train to your current fitness / physiology, not the physiology you want. Shooting for your goal pace too early or ratcheting down to an unrealistic workout pace will stress your body too much, leaving you burnt out for the next session or even the remainder of the week's scheduled training.
You can get a reading on your fitness by doing an occasional 5k time trial. These can serve as benchmarks throughout training to monitor fitness improvements. Run, extrapolate pace, and adjust if necessary. Don’t be afraid to reframe your goals and training if fitness isn’t rapidly improving (it might not!).
Training is complete, and now is the time to rest up for race day. A proper 2 - 3 week taper, during which you’ll reduce training volume but maintain intensity, will be crucial to leave you feeling rested, sharp, and fit for the marathon.
Don’t be afraid of losing fitness during this time; all the work should now be be done. Fitness won’t likely improve, but performance should. On average, athletes experience a 2% - 3% improvement in performance after tapering.
Training is synonymous with preparation. The months of consistent tempo workouts, long runs, and dedication to nutrition should leave you feeling only minor anxiety. So what if you haven’t actually run a full 26 miles? Marathon training has prepared you to tackle this distance stronger than ever before. Anything that could go wrong during the race, you’ve probably already experienced in training. Race day is the time to shine.
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