Bike-run brick workouts

Many of us live and train where cold weather and short days limit our outside cycling for a few months out of the year. To improve fitness we can utilize combined bike/run indoor to outdoor workouts. Here are a few aerobically challenging workouts that add variety. 

Endurance session;  This is a great session for an indoor bike and treadmill. The constant change from bike to run helps our legs adapt to transitioning in multisport events. Keep heart rate at ~71-75% of Max HR. If you only have an hour, this workout could be shortened to 10/10/10/10/10 but keep the disciplines in the same order. This session is as follows; 20 minute bike/20 minute run/20 minute bike/20 minute run/20minute bike.  If you have power on the bike record average watts and distance covered on the run.

Lactate threshold-boosting session; On an indoor stationary bike or trainer, perform 15-20 minute easy warm-up including 3 x 1 minute single leg riding and a few high cadence spinning intervals, spin easy for 2 minutes before performing 10-15 x 1 minute at 105% of FTP (average functional threshold power in watts during a 20 minute bike TT) with 1 minute easy spinning between each speed interval. After the last 1 minute interval, hop off the bike and run a 3.1, 5 or 6.2 mile loop at tempo pace or ~30-45 seconds above race pace for each distance selected.  The length of the run depends on your level of development or goal race distance (sprint, olympic, half, etc).

Perform each of these sessions in a week with the other training days being easier endurance or functional strength training sessions.

Building your aerobic engine.

To continue with the ongoing theme of this blog I encourage the reader to review previous entries and follow along with the steps outlined in each entry over time. Reading these entries consecutively will give a clearer understanding of the big picture for long term-improvement I am aiming to project.

Once you have a handle on priorities, a schedule of upcoming races, a fitness plan, a positive perspective, a mantra to draw strength from, you have incorporated core strength workouts; it is then time to focus on effectively improving aerobic endurance.  If you are competing in running events of 5K to marathon, bike races, triathlons and duathlons etc., the primary emphasis in your training should be on improving aerobic endurance, more often termed your aerobic engine. 

There are numerous sites that go into training zones and how your body utilizes fat and glycogen as fuel sources or the percentages of lactate produced in each zone, VO2 Max%, or % of Max HR, etc, but to keep it simple, I will focus on Max HR%, considering most heart rate monitors use this as a reference.  However, to understand Zone 2, we still need to be aware of the 5 heart rate training zones and they will differ in some literature but these are the zones I utilize to assign heart rate for myself and other athletes I work with.

Zone 1; (50-65% of Max HR) Breathing very easy, a pace one can do for hours.  This zone is great for long, slow endurance base building or short recovery workouts of ~20-40 minutes to flush metabolic waste from a previous workout. If you can work out for a large block, ~3-8 hours/day, you are one of the lucky few to have the opportunity of training in this zone all day long (and take naps after eating a huge meal).

Zone 2 (66-75% of Max HR): This zone is where a person with a busy schedule (able to train 6-12 hours a week) should spend 50-85 percent training during most of the training phases after building an aerobic base with work in zone 1 (more on this later). In zone 2, we are burning mostly fat (~85%) and the rest glycogen (~15%).  Some lactate is produced in this zone but not enough to hinder recovery after ~ 8-24 hours if the workout is kept under 60-90 minutes, for more advanced athletes and even under 45 minutes, for many beginners.  The beauty of training in this zone is it will improve; fat utilization, lactate threshold (gradually), capillary development and it will strengthen the heart to deliver nutrients more efficiently. 

Zone 3: (76-80% of Max HR) Tempo pace, comfortably hard, but less than max effort (or 5K to 10K pace) while your body is burning both fat and glycogen at nearly equal levels.  This is described as a pace that can be typically held for 30-60 minutes in most workouts. Great for building strength and improving lactate threshold for longer races and workouts need to be carefully planned as too much training in this zone can lead to breakdown. This zone has similar improvements as Zone 2 but more taxing with the increased lactate production and increased use of glycogen.

Zone 4: (80-91% of Max HR) 5K or 10K running pace for most, unless a person's lactate threshold is lower compared to the majority.  Use this zone sparingly 1-2 times per week at most.  In triathlon training, this zone can be utilized a bit more frequently compared to an athlete that focuses on one sport.  Still this zone is very taxing, and if done too often can lead to over-training or injury.  This is the next most important training zone for race preparation and I will talk about this zone in more detail in a future blog entry as the race season approaches.

Zone 5 a, b and c: (92-100%)  This zone is rarely used in longer endurance events except during a sprint finish.  We can train in this zone briefly at different stages of training cycles with short quality sessions but should spend very little time compared to other training zones. It can be used in short duration to build fast twitch fibers and does build endurance moderately (compared to the other zones).  *One of my favorite quality sessions includes 30 second intervals in Zone 5a, followed by 4.5 minutes of active rest.

Back to Zone 2; by targeting this zone during most workouts we are using the most effective workout in terms of gaining aerobic fitness with the least amount of risk to our health (getting injured or overtraining).  Mark Allen (a multiple ironman winner) and numerous successful endurance athletes touch on the importance of training in this zone and the effectiveness of building a large aerobic engine before moving onto tempo intervals (Zone 3) and then race-paced interval work (Zones 3-4). 

For simplicity in finding your zone 2 heart rate range, use the Karvonen method (taken from Wikipedia); 

First, take 220-your age to get approximate max HR.  In this example 220-38 = 182

The Karvonen method factors in resting heart rate (HR_rest) to calculate target heart rate (THR), using a range of 50–85% intensity:

THR = ((HR_max − HR_rest) × % intensity) + HR_rest

Example for someone with a HR_max of 182 and a HR_rest of 42:

50% Intensity: ((182 − 42) × 0.50) + 42 =  112 bpm

*75% Intensity: ((182 − 42) × 0.75) + 42 =  147 bpm (beats per minute)*

85% Intensity: ((182 − 42) × 0.85) + 42 =  161 bpm

*Another recommendation is to add 5 beats to this number if you tend to have a higher heart rate max compared to the average calculation of 220-age.

For this individual, workouts spent training in zone 2 would be at or close to 147 bpm on most days. This will allow the athlete to stress the aerobic system enough but with less risk to over-train and improve fat-utilization (large supply) and use less glycogen (limited supply). Ultimately, this will require less time for the athlete to recover and allow them to get back to the next training session more frequently without carrying over significant fatigue.