Fast Forward Triathlon’s Eric Bean on Training, Testing, and Coaching with Power
In this article I will describe how I perform cycling lactate threshold (LT) testing for the Fast Forward Triathlon (FFT) ProDevelopment Team, and how I specify training zones based on LT power (LTP) and LT heart rate (LTHR). I will also briefly describe how to periodize a season and provide example workouts.
It’s no secret that strong cycling is important for triathlon: cycling comprises slightly more than one half of triathlon duration for all race distances from sprint to Ironman, and more capable cyclists are less fatigued for the run. However, the multisport community faces several challenges in training effectively in cycling. The first is a general knowledge deficit: while many multisport athletes have high school or collegiate experience as a tack/cross-country runner or swimmer, far fewer received that same level of coaching and competition experience in cycling. The second challenge is one of logistics: riding from home to a workout destination and back can take longer than the workout itself and expose the rider to the dangers of the road, especially during evening rush-hour traffic. Furthermore, it’s harder to gauge intensity on the bike. Whereas in the controlled environment of the pool or track velocity accurately corresponds to intensity, speed on a bike is subject to the variances of hills, wind, and traffic. For these reasons, I prefer to do certain hard workouts on a stationary trainer, and use power as the benchmark for intensity. Of course, this necessitates performance testing.
LT is the best predictor of endurance performance in events lasting 30 minutes or longer.
Lactate Threshold (LT) is the intensity beyond which an athlete fatigues rapidly, and below which an athlete can continue for hours. A well-conditioned athlete can maintain LT intensity for an hour in a race situation when tapered. LT is also the best predictor of athletic performance in endurance events longer than 30 minutes, even better than VO2max. Since nearly all triathlons are longer than 30 minutes, a triathlete’s most important training goal is to raise LT velocity (on the bike we use LTP as a surrogate).
Scientifically, LT can be defined in many ways, but I prefer to define it as the inflection point in the blood-lactate accumulation curve also known as the “onset of blood lactate accumulation” (OBLA) (Figure 1). Beyond OBLA the body cannot clear lactate from the blood as quickly as it is produced and an athlete fatigues rapidly. Let me be clear, lactate does NOT cause fatigue or the burning sensation in muscles, but rather other metabolic processes cause fatigue and lactate is an easily measurable surrogate marker of fatigue.
Figure 1:Pro female (Kristin Lemos) LT test performed on a Lab CompuTrainer in egometer mode
Performing an LT test is simple in concept and provides a valuable outline of. Since LT can be maintained for an hour in a race situation, a valid field-test for those without an ergometer is a 40km (~1 hour) time trial on a flat course in good conditions. Another option is to do a 20km or 30 minute TT in training (on a flat course or stationary trainer). LTHR and LTP are your average HR and power for the 40km TT, or the average HR and power of the final 20 minutes of the 30 minutes/20km TT. Keep in mind that the shorter test may slightly overestimate LTP.
At FFT we perform LT tests in ergometer mode on the CompuTrainer, who has been a partner and sponsor of FFT since 2010. This gives us the greatest control over, and accuracy of, the test. Each athlete performs a power ramp test and I take blood samples during each work interval to plot the OBLA curve and thus find LT at the inflection point between the slow and fast accumulation of lactate (280W in Kristin’s test in Figure 1). Women start at 140W and men stat at 150W, and perform an easy “lactate clearance” interval of 4 minutes to establish a baseline—In elite endurance athletes lactate concentration ([La+]) paradoxically decreases during the early potion of an LT test (first 4 data points in Figure 1) because minimal lactate is produced at low intensity but clearance mechanisms increase. Lactate, HR, and perceived exertion are recorded at the end of each interval. After the first interval the load increases 40 and 50W for women and men, respectively. Subsequent intervals are 3 minutes with a 20W (female) or 25W (male) ramp. The coach should note when the athlete’s breathing changes from smooth and rhythmic to labored. This is known as the ventilatory threshold (VT) and indicates that the athlete is buffering lactic acid by breathing off non-metabolic CO2, and it should correlate with OBLA when you plot [La+] as a function of power. VT is highly accurate, and for the trained coach who does not have a lactate analyzer, it is a reasonable method to use in place of lactate blood samples. VT and LT should also correlate to a perceived effort of 15-17 on the Borg Scale. In my experience athletes tend to feel that their test LT is harder than the effort level they believe they can maintain for an hour. The LT test is completed when the athlete is clearly beyond OBLA. Note that this is a sub max test, and is not taken to exhaustion. This is the same test protocol that USA Cycling uses with their elite athletes.
Using the LT test to define training zones:
Table 1: Cycling training zones defined by %LTHR
Table 1 describes the cycling training zones we use for FFT athletes. You’ll notice that there is an intensity gap between Recovery and Aerobic Development and again between Tempo and LT. The first gap is to emphasize the concept that Recovery rides are easy and should not flirt with a workout aimed at increasing one’s aerobic base. Also note that there is no minimum level of intensity for Recovery rides, the goal is simply to pump blood through the muscles and enjoy being on the bike. The gap between Tempo and LT is a reminder that intensities close to LT, but not at or above LT are low-yield in terms of raising LT. Ideally, LT intervals are done at or slightly over LT, but we use the 98% LTHR value as the bottom of the LT zone to accommodate cardiac drift early in the workout (at a steady intensity, it takes HR some time to catch up). When fit and rested, it can take half the duration of LT intervals for an athlete’s HR to reach LT.
Correlating the training zones to power is simple. For LT intervals use 100% of LTP. For example, if your LTP is 300W, use 300W for you LT intervals, until 300W is too easy, and then increase (usually ~1-2%/week). For recovery rides, power isn’t important. For Aerobic development and tempo workouts, use a steady state power such that you HR achieves the HR goal by the first third of the interval. Tempo is typically 90% LTP, and VO2 is 105-110% LTP, but each athlete will vary based on their critical power curve.
Table 2: Example workouts by periodization phase
|Rides of desired duration in Aerobic Development and Recovery zones.
|Form sprints, single leg drills, high cadence drills. (continue this session weekly for the entire season)
|Weekly big-ring hill climbs for strength with equal time recovery.
|Weekly tempo interval: Build from 30 minutes to 60+ minutes during the Economy phase.
|Weekly VO2 intervals of 3-5 minutes at high cadence with equal time recovery. Total interval duration of 15-20 minutes.
|Continue Tempo intervals, or start light LT intervals.
|Weekly LT intervals of 6-20 minutes at race cadence with ¼-½ time recovery. Total interval duration of 30-60 minutes.
|Race simulation rides. Example workout for70.3 and Ironman: warm-up then 80% of race duration at goal race pace (power).
Of course, athletes need a recovery week every 3rd to 5th week. The end of the recovery week, or start of the following week, is a good time to test for fitness gains with a 20-30’ Tempo interval noting power, HR, and distance. I prefer the sub-max test as a routine training test as it is not intimidating and we have races to test our maximal fitness. At FFT we do not do “test workouts” per se because by doing our key workouts on the CompuTrainer in ergometer mode, each workout provides objective data on fitness improvement. The constant feedback of power data allows the athlete and me to fine tune workouts and adjust the timing of recovery weeks.
Train hard, recover well, and have fun!
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Eric Bean is a former professional triathlete and the coach of the Fast Forward Triathlon Pro Development Team presented by Inside-Out Sports. Prior to founding FFT, Bean was the head coach of the Stanford University Triathlon Team, and the USAT Collegiate National Champion. Bean’s breadth-upon-depth understanding of triathlon training is guided by his athletic background as an NCAA swimmer and runner, and time trial master’s national champion cyclist. Eric holds a BS in Aerospace Engineering, an MS in Biomechanical Engineering, and is currently completing residency in Anesthesiology & Pain Medicine at the University of Washington in Seattle. You can reach him at [email protected].
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