DAY TYPES OVERVIEW for THE YEAR of the ENGINE
Click on a link for a detailed explanation each day’s stimulus, as well as how to approach it
ENDURANCE DAY: Consistent, low-intensity, Zone-2 training
Endurance Day means work about 7/10 perceived effort, or 70-75% max heart-rate. This may feel slow, but that’s OK. Endurance Day increases oxygen supplied to working muscles by increasing blood pumped per heartbeat (stroke volume) and capillary blood supply to working muscles. The goal is to maintain a constant pace as the training days get longer.
SPEED / THRESHOLD DAY: Consistent, high intensity race-pace training
Speed / Threshold Day is a single, high intensity training block. Work at the highest pace can sustain for the entire segment, but any increase would quickly cause fatigue. It’s about 8 / 10 perceived exertion. Speed Day increases your speed at threshold intensity and helps you gain comfort at or near the redline. Do not sprint at the end of a speed day.
ANAEROBIC DAY: Max effort sprint day
Anaerobic day is a series of intervals with short work and long rest. Anaerobic Day increases your top end speed by enhancing the energy produced in your fast twitch muscle fibers. Anaerobic day relies primarily on a glycolytic system. For each interval, go as fast as you possibly can, even if your scores drop off a little bit.
INTERVAL DAY: Classic interval training at various intensities
Interval intensity depends on the duration of the work and rest interval. The primary objective of interval day is consistency. Get the highest possible score every round, with the smallest drop off between rounds. Intervals can develop both aerobic and anaerobic power.
TIME TRIAL: Important monthly benchmark
Time Trials are monthly 10-minute tests. We also compare your time trials alongside other Day Types to quantify the contribution of different energy systems and adjust as needed.
MAX AEROBIC POWER DAY: Short intervals, short rest
Max Aerobic Power Day features a high interval count and short rest period. With short rest, athletes cannot rely excessively on the glycolytic system, or they will not be able to recover. If you are not sure what pace to use, start slowly and increase gradually until you can no longer increase in speed. As with any interval day, consistency is paramount.
POLARIZED: Advanced endurance days
Polarized Days are endurance days with occasional bursts of speed and power. Complete Polarized days at endurance pace. The 7-second bursts should be max effort. After 7 seconds, end the burst and recover at endurance pace. The purpose of the burst is to deplete your phosphocreatine stores, which increases mitochondrial activity.
ROCKET RACES: Paired intervals develop speed
Rocket Races occur in pairs each week. Rocket Race A is an interval in which rest duration exceeds work, so these will be fast paced. Rocket Races B will feature the same number of work intervals and the same work duration, but with less rest. The challenge of Rocket Races is to match your pace from Rocket Race A in Rocket Race B, despite the shorter rest.
FLUX DAY: Endurance days with zero rest intervals
Flux Day is an endurance day with intervals of higher intensity. The Flux intervals specify a percentage increase, so Flux = Endurance +20% means increase your speed by 20% for the Flux interval. Upon completion of the Flux interval, return to endurance pace and continue until the next Flux interval.
HYBRID DAY: Two sets of intervals for broad muscle fiber impact
Hybrid Days are double intervals. After the first intervals, there is a Set Rest Period and then the second interval block begins. Set Rest is in addition to any rest from the intervals. As with other intervals, consistency is the primary goal. The pace will be very different for both blocks, but be consistent within each blocks. Hybrid’s configuration recruits an enormously broad spectrum of muscle fibers.
FLUX STAGES DAY: Flux intervals with increasing intensity
Flux Stages Days work the same as Flux Days, except that there are multiple Flux blocks at increasing intensities. For example, there might be 3 Stages at 10%, 3 at 20%, and 3 at 30%. This means to work at your endurance pace plus 10%, 20% and 30%, respectively. In between the Flux Stages Intervals continue at Endurance Pace.
ASCENDING DAY: High intensity pacing and top end speed
Ascending Days are intervals which increase in pace each interval. Determine your starting pace from your time trial and then set that pace for your first Ascending interval and increase in accordance with the guidelines until you can no longer complete an interval.
DEVOUR DAY: Improve aerobic capacity of fast twitch fibers
Devour Days are dynamic intervals; there are changes in work, rest, and pace. Pace is calculated based on your time trial. The varying work and rest allows for a broader stimulus of muscle fibers at high, but sub-maximal, intensity. Some Devour are Ascending or Descending, meaning that in addition to increased work times, there is declining rest and increasing pace. All you need to do is hold the specified pace.
INFINITY DAY: Increase aerobic power of fast twitch fibers
Infinity Days are dynamic intervals in which many parameters vary. Your pace is calculated based on your Time Trial results and will vary. Infinity combines all of the features of Devour, but with multiple parameters varied to intensify the stimulus. The final block of Infinity is a “to-failure” block. Simply hold the specified pace for as long as you can.
TOWERS DAY: Improve endurance of fast twitch fibers
Towers Day comprises three blocks with set rest between them. In all cases, pace is specified based on time trial results. The first block, you’ll increase each interval. For the second block, you’ll stay at a high level (above threshold) and then the final block is ascend-to-failure.
AFTERBURNERS DAY: Increase top end speed and improve recovery from intense bursts
Afterburners Day comprises three blocks with set rests between them. The first block is a series of max effort intervals with short rest, to fatigue fast twitch muscle fibers. The second block is work at a high level (above threshold) and the final block is ascend to failure. Afterburners day increases top end speed and recoverability at high intensity.
ATOMIC DAY: Develop ability to buffer / neutralize byproducts of anaerobic energy production
Atomic Day contains two blocks. The first block is a max effort sprint block. The sprints are short duration, so attack them all-out, even if your pace drops. The final block is an interval block in which your pace increases until you are unable to continue.
SYNTHESIS DAY: Increase capacity of all muscle fibers for advanced athletes
Synthesis days are four blocks, each with set rest between them. The blocks are either max effort sprint blocks like those in atomic day, or interval blocks, similar to Interval Days. For the sprint blocks, max effort! For the interval blocks, consistency is paramount.