I Ran Everyday For 30 Days, It Changed My Life
In a Nutshell
The creator ran daily for 30 days using zone 2 training and Norwegian intervals, raising his VO2 max from 58.3 to 61.3 while preserving all muscle mass and dropping 1% body fat. Proper sequencing of cardio after weights, higher carb intake, and strategic pacing enabled him to finish third in a Hyrox competition against elite international teams. The key lesson is that structured endurance work can be added to strength training without sacrificing muscle if recovery, nutrition, and training order are managed correctly.
These notes were generated by AI and may contain inaccuracies.
Running is often viewed negatively due to its difficulty and the belief that excessive cardio will reduce muscle gains. The experiment involves running daily for 30 days while using MRI scans to measure muscle changes, alongside multiple tests tracking body composition and heart health. The challenge culminates in competing in London against top athletes and influencers.
A VO2 max test was conducted to establish baseline cardio fitness. The average gym-goer scores in the mid-30s to 40s, while elite athletes reach much higher values, with Cristiano Ronaldo rumored to have scored as high as 75. The test revealed a day-one score of 58.3, placing the participant in the top 2% for his age despite minimal prior cardio training.
Two critical problems were identified from the test data. The respiratory exchange ratio showed the body had become inefficient at burning fats for energy and instead preferred burning limited carb stores. Post-test blood work revealed lactate levels of 10.5, which is very high. Lactate accumulation during intense activity causes hydrogen ions to build up, creating painful burning sensations in muscles. In extreme cases, this can lead to vomiting, nausea, and even death.
Zone two training was introduced to address lactate clearance and fat-burning efficiency. This involves maintaining heart rate at 60-70% of maximum, which for the participant equals 120-140 beats per minute. A key indicator of proper zone two intensity is the ability to hold a conversation without excessive heavy breathing. Sessions require 45-60 minutes minimum to achieve full benefits.
After the first run, sharp pain developed on the outside of the foot, specifically at the base of the fifth metatarsal. The upcoming race is Hyrox, which consists of running 1 km followed by a weights or cardio station, repeated eight times, ending with 100 wall balls. Physiotherapist Rajan diagnosed improper joint or tendon mechanics across the bottom of the foot. Worst-case scenario involved amputation (jokingly), while best-case recovery was estimated at a couple of weeks with rest.
A 2021 meta-analysis combining 27 studies examined whether cardio paired with strength training negatively impacts muscle growth. Results showed those combining cardio with weights experienced essentially the same muscle growth as weight training alone for beginners, but a slightly negative effect was found for trained individuals. Three rules were identified to prevent muscle loss:
- Perform cardio after weights or later in the day, never before
- Increase carbohydrate intake to match elevated energy expenditure, focusing on quick carbs before workouts and complex carbs immediately after
- Protect leg days by scheduling long runs to avoid interfering with weight training recovery
Physiotherapist Rajan, who has competed in Hyrox, began teaching proper technique for the competition stations. The transition from bodybuilding-focused training to hybrid endurance training was identified as particularly challenging. Training continued at reduced intensity initially to protect the healing foot.
The training plan incorporated two long, easier zone two cardio sessions weekly alongside three intense sessions using the Norwegian training method. This protocol involves pushing maximum effort for four minutes, followed by three minutes of easy recovery, repeated four times for a total of 30 minutes. This approach mirrors how the participant previously conducted cardio, potentially explaining the high initial VO2 max despite limited training frequency.
The full competitor list revealed participants including winners from the show Physical 100 representing Team Korea. The competition includes the fittest individuals from 16 countries. The foot injury had resolved, allowing return to running and training pain-free.
Cardio training at moderate to high intensity releases anandamide, known as the bliss molecule, which attaches to the same brain receptors that respond to THC. The runner's high typically occurs after 20-40 minutes of sustained cardio effort. This differs from weight training, which involves short intense bursts followed by rest periods that prevent sufficient sustained effort for the effect.
A practice session covered 80% of a full Hyrox course with competitor Jeff. The duo completed the circuit in 55 minutes and 21 seconds despite making station modifications. The practice revealed the importance of strategic station allocation based on individual strengths, with Will Tennyson (originally planned partner) expected to handle more sled work while the participant would focus on burpees, ski erg, and rower.
Weight dropped 3 pounds despite consuming 2,600 calories daily. The Built With Science Plus app detected excessive weight loss rate and adjusted the calorie target to 2,800 calories per day. The app functions similarly to a real coach by adjusting plans based on body composition changes and provides weekly workout modifications.
A volume PR was achieved during week three despite increased cardio volume. The improvement was attributed to enhanced lactate clearance from cardio training, which also benefits strength training by reducing hydrogen ion accumulation during higher-rep sets. This allows muscles to work harder and recover faster between sets.
Pro Canadian Hyrox competitor Cole Learn advised maintaining lower heart rate off the start rather than pushing maximum effort immediately. The rower station was identified as a recovery opportunity rather than a time-gaining station, since excessive effort there risks skyrocketing heart rate and depleting energy reserves.
The venue in London featured competitors from 16 countries including Team Korea and Team France with a Hyrox champion. American competitors appeared stronger than initially anticipated. Pre-competition VO2 max retesting showed improvement from 58.3 to 61.32 ml/kg/min, placing the participant in the 99th percentile.
MRI scans showed no muscle loss in upper body or legs after 30 days of combined cardio and weights training. DEXA scan revealed 1% body fat reduction despite consuming the highest calorie intake ever while losing weight. The participant aimed for a top-three finish despite acknowledging not being the most muscular competitor present.
The race began with many competitors sprinting ahead, creating pressure to chase. The strategy of controlled pacing was maintained. South Korea secured first place and France took second, leaving one podium position contested. Team Canada crossed the finish line after maintaining position through strategic pacing and mental resilience during the final stations.
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