Episode 45: How to Get Fast With Swim, Bike, and Run Intervals

In this week's episode, we are bringing it back to basics with Intervals 101. We cover what intervals are (and what they are not), why do intervals, when to start doing intervals, how to determine what intervals are appropriate for you, basic considerations and mistakes with intervals, and examples of a basic interval progression in our programming. We also cover lots of fun coaching and training insights related to the off season, using repetition as a way to track progress, overcoming workout anxiety, positive mindset tools, defining race goals, the magic of high-carb fueling, and more. We had so much fun with this episode—check it out!

Intro Banter

Katie is feling recovered! Talk about how great it has been to lean into the off season / recommendations to other athletes to do this (many of my athletes have started to feel the effects of a LONG season) 

  • Physical metrics: HRV, RHR, sleep, overall good energy 

  • Mental metrics: excited to get outside and move! 

  • How I’m approaching next few weeks:

    • Still a recovery phase – no hard workouts 

    • Strength: stability, anti-rotation, etc. and fixing the listing things

    • Endurance: whenever I can, switching things up in terms of movement planes and activities

      • Yoga 

      • Pickleball (lol)

      • Harvard stadiums 

      • Hiking 

      • Some SBR because it is convenient, but all fun and social Zone 1/2 

Coaching and Training Insights

Katie: 

  • A useful way to track progression - repetition 

    • Can be exciting to do lots of different workouts and keeps things interesting, but sometimes the best way to check in on how you are performing day to day is via repetition 

    • Examples:

      • Doing the exact same swim set for a series of weeks – sometimes you will be faster, sometimes you will be slower, but on average you should be trending faster as you build fitness

      • Doing the exact same route multiple times and seeing what your pace/HR is – I especially like this for trail running (example from trail run over the weekend)

    • For me, this feels less stressful than regular “testing” for benchmarks. It’s just part of your regular training, but a nice way to see progress over time

    • On the flip side, big declines can give you a window into challenging conditions: are you getting sick? Tired? Weather is hot/humid? Etc. 

      • Weather is a big pitfall here so be sure to use the JAHI!

  • Jim: High performers thrive on boredom and repetition. If you constantly need a new workout or variation, you are probably more focused on entertainment than process and performance.  High performers keep it simple, low stress. They practice the fundamentals over and over and over. 

    • Great read: The Mundanity of Excellence

      • “Excellence is mundane. There's nothing 'special' about high performers. They just have a set of habits, practices and mindsets that individually aren't particularly groundbreaking, but when added together and compounded over a long period of time, result in the phenomenon of excellence. It's all very mundane.”

    • Jim: Organic fitness testing is way more enjoyable than a formal threshold test.

  • Some athletes reporting anxiety about executing HARD workouts

    • Many of my former IM or 70.3 athletes are closing out their seasons with sprint/OLY training and racing which is hard in a different way 

    • One athlete remarked: a run that had 20’ at OLY race pace off the bike felt more intimidating than a run with 60’ at 70.3 race pace off the bike!

    • This is totally normal – short and intense workouts often hurt a lot more. One day in the spring I told my coach that I would rather race an Ironman tomorrow than race a mile on the track (and as a result she had me do a LOT of hard track and tempo workouts until they weren’t so scary)

    • Anything new/uncertain often causes anxiety. Exposure is one of the best things you can do. Worst case you don’t hit your intervals, and that is OK! Will help us make a race plan going forward. In my experience the anticipation is so much worse than the real thing (true for racing too) and the more you do it the less scary it is.

    • Jim: “We suffer more often in imagination than in reality.” - Seneca

  • Advice for life that is also advice for racing and pre-race mindset: how to not catastrophize 

    • Catastrophizing = assuming the worst case scenario will happen

    • In a race: well I’ll probably get a flat; I’ll probably walk the marathon; I’ll probably have GI issues

    • From a psychological standpoint, the more we do this, the more we create neural pathways that do this in the future. Imagine it like a groove in a piece of wood from a knife

    • One way to work against this is to force yourself to also imagine that the best case scenario happened

      • I PR’ed 

      • I had no GI issues

      • I won the race 

      • Etc.

    • You might not believe it, and that’s fine. Even if you don’t believe it, the PRACTICE of imagining the best case scenario is usually because it creates new neural networks. Eventually, you may always think of both the best and worst case scenarios automatically (or bias towards better scenarios) which can help manage pre-race stress and anxiety 

    • This is a life skill too! Any time you catch yourself assuming the worst, try to imagine the best.

    • Jim: Humans have a natural negative bias because this is a survival instinct. We are alive now because generations before us were cautious and probably weren’t full sending out on the plains or on the farm.  But, luckily, we have a very evolved frontal part of our brain that can distinguish between real danger and imagined danger.  Defining and drawing that line is a mental skill that requires a lot of conscious practice.  

  • A listener (athlete) question that could also be an insight: if you are sick, when should you take extra rest and when should you push through?

    • General rule of thumb: if you have a fever, aches, any symptoms below the neck (chest congestion, cough, etc.) or GI issues, take the day off and focus on resting and hydrating 

    • If you have a cold and are just congested but energy levels are OK, I sometimes find that an easy Z2 ride or run can help flush things out. I would still avoid hard workouts and shut it down if you start to feel worse 

    • Also helpful to track metrics like RHR and HRV - this can tell you something about how deep the sickness is or if it’s more just a nasal congestion situation

    • Remember our rule for injuries / niggles: sometimes 1-2 days off can prevent 1-2 weeks or months off! Going all in on recovery can pay off and get you back on your feet faster than half-assing it for weeks 

Jim: 

  • The difference between strength and coordination. You can be strong but if you are not coordinated, you will not move efficiently or even properly. Your muscles need to fire in the correct order.  This underscores the importance of technique development, particularly with swimming and running. Don’t skip your drills!

  • The importance of defining your race goals especially for some of these late season races. Some athletes are using late season short races to really test their well earned summer race fitness. They are going all out to race it before they take an off season. It’s a high risk / high reward strategy.  Typically these athletes have achieved their goals for the year and are really just letting it all hang out before the off season.

    • Some athletes are using these short races to set themselves up for their last long race of the year. Their approach is a bit more conservative and they aren’t necessarily looking to PR at a Sprint or OLY.

    • Whatever your late season race goals are, take a moment to really define what you want out of your last races as this will most likely be what you remember the most heading into next season. Your brain will often consolidate on your last reps.

  • Fueling: The difference between 60 grams of carbs vs 80 grams can be HUGE. We are seeing so many athletes this year hit new performance levels just by increasing their carb intake by 10 - 20%. That may not sound like much but it’s the difference from feeling sort of like you are fading at the end of a race to finishing really strong.

Main Content: Intervals 101: Get fast with swim, bike and run intervals. 

What are intervals?

Let’s start with a typical one hour workout. 

An easy run of 60’ is not an interval. And often this run is Z3 for uncoached athletes. It’s not easy enough or hard enough to stimulate an adaptation.

An interval happens when we begin to slice up the time pie into smaller chunks to target certain adaptations.  For example, the 60’ run becomes a Z1/Z2 20’ warmup, 2 x 10’ at threshold pace with 2’ easy between and 15’ cool down.  

We commonly think of intervals as the times when we are doing the actual work.  In the above example, we focus on the 10’ work increments, however, the interval and workout structure changes A LOT based on the recovery interval. A 2 x 10’ threshold pace workout with 1’ recovery is very different from a 2 x 10’ threshold pace workout with 5’ recovery. The first interval set is a near continuous interval of 20’ of work. 1’ is not a lot of time to recover and is really just a psychological break as your HR and lactate will remain high going into the 2nd 10’ interval.  

But if you add a 5’ recovery interval between the 2 x 10’ intervals, you get full recovery and it is two distinct 10’ intervals. 

You may use the 1’ recovery intervals as you get closer to race day to mimic race demands and use the 5’ recovery intervals earlier in the year or Base period to challenge but not overload the athlete. 

Important point: While we talk about Zone 2 a lot, there is only one energy system. There are no silos or zones in the body. Training in one “zone” will have an effect on all other “zones”.   An easy run not only helps build out your aerobic foundation, it also helps raise your threshold and VO2 max. When we include intervals within a workout, we challenge the body to work more in multiple physiological “zones” or levels.

Why do intervals? 

Recruit slow and fast twitch muscles

Turn on all motor units; you need muscle engagement to grow a muscle.

Challenge the heart / aerobic system to increase stroke volume. Deliver more blood and oxygen to your muscles.

Mental race preparedness - mimic race demands

As a coach, we are programming around what are we trying to improve with this athlete.  What is their current fitness, skills and capabilities and how do we best use the time we have to move them to the next level specific to their “A” race demands?

When should I start doing intervals?

It is important to have a basic foundation of fitness and aerobic training before you start intervals.  Intervals are powerful medicine and you will do more damage than good if you start them too early in a season and/or in your athletic development.  

When in doubt whether you are ready for interval training, do more Base work. You can never be too robust!

For example, I have a returning triathlete / marathon runner who just started this week on a marathon plan for Philadelphia marathon which is in late November.  Her average weekly miles are ~15.  Given this is fairly low volume heading into a marathon plan, our first priority is frequent, easy runs. Over the next 4 - 6 weeks we will focus on ramping up easy run volume with some 20” pickups/strides before we introduce any type of run interval or speed training. 

How do I determine intervals appropriate for me?

Need to first measure your current thresholds. In other words, what is my current fitness level and set a baseline to measure your improvement.

Swim: 400/200 best effort, take average time to determine your Critical Swim Speed (CSS)

Bike: Functional Threshold Test - 30’ warmup, 5’ all out effort, recovery into a 20’ best effort. Take .95% of Normalized Power from the 20’ test.

Run: 2 x 10’ best effort. Average times and add 30”. 

Lactate / HR / pace / watts testing in a lab.

Garmin Guided Lactate Threshold Test.

Main considerations for intervals: 

There are three levers for intervals: 

Duration - how long is the work and rest interval 

Frequency - how often are we doing intervals in the week/micro/mesocycle

Intensity - the primary adaptation we desire will dictate the level of intensity. 

Important: As coaches, we value them in that order. 

If the intervals are too hard, we lose training time.  We value volume and consistency more as this will serve you best in the short and long run. 

You will probably do 50-150 interval sessions per year. As such they need to be sustainable. If you are destroyed or discouraged every time you do intervals you will stop doing them. 

Think accumulated work duration (AWD) over a period of months as the goal.

For coached athletes, we emphasize commenting on how it felt in TrainingPeaks as it is important for us to learn what is happening during this work. It’s not always about the numbers.  

Beside the numbers, we are looking for: 

  • How it felt

  • Consistency 

  • Where was your mental game when things get tough

When in doubt, keep your intervals simple. You should be able to easily remember your interval workout. A workout that needs extensive notes that you have to refer to during the workout is probably too complicated. Less is more.

Always leave one rep in reserve. End every interval session knowing you could have done at least one more.  Frequency and sustainability are the keys to long term athletic development and performance. 

Is Training Stress Score (TSS) a good measure of interval effectiveness?

No. TSS is not the arbiter of a good interval workout as TSS really favors volume. 

Basic Interval workout progression:

*Activation: This happens before you even begin to swim/bike/run. Particularly with running, we recommend a few minutes of glute activation.

*Warmup:  It is very important to transition your body from resting HR to active HR to very active HR. The longer and gentler the warmup, the better you will perform your intervals. This physically and mentally prepares you for the work. 

*Primers: Wake up the body / muscles / mind. Prime the pump for the hard work. 

Swim - 4 x 25’s FAST with 20” rest.  

Run - 2 x 2’ at tempo / half marathon pace. 

Bike - 6 - 20” hard effort / 40” easy

*Main set:

This is where the fun happens! Intervals combinations are endless. Use the above guidelines to develop your interval training. 

Some common interval workouts we like during the Specific Phase:

Swim:

  • Fast 50’s - 100s.

Run: 

  • 6-10 x 1-2’ at 10K / 5K pace

  • 2 x 10’ at half marathon pace

  • 200/400s on track

Some of our favorite half marathon and marathon intervals in our How to crush your best fall marathon or half marathon podcast.

Bike: 

  • Sweet Spot - 5-7 x 7-10’ at 92% FTP

  • Threshold - 5-10 x 5-20’ at 100% FTP

  • VO2 max - the classic 3-5 x 5’ at 125% FTP with 5’ recovery is a staple. The goal is to accumulate time at ~90% of max HR. Rarely are most athletes going 95-100%.

  • You can download our Zwift workout trainer sampler for Zone 2, Tempo, Sweet Spot, Threshold and VO2 max workouts.

*Cool down: Keep it simple, easy 100-200 in the pool, 3-5’ walk at end of run, 5’ - 10’ easy spin on bike.  A good cool down will set you up for recovery from this workout and set you up for the next workout.

For additional reference, you can check out Our Favorite Ironman and 70.3 Workouts podcast.

Common Interval Mistakes: 

Modifying the intervals such that you don’t get the stimulus / adaptation that you intended. For example, if you have 2’ at 5K run intervals but then modify them to .5 mile at half marathon pace, that is a very different workout. 

Once you have a plan, try to stick to the plan.  (Unless the plan is inappropriate for that day for whatever reason.)

In general, athletes who modify their workouts a lot, are the athletes who most underperform at races. 

Burying yourself on the first interval and then slowing down on subsequent ones. You want to do the opposite of this.

Too much, too soon, too fast.

Challenge of the week:

Katie: End of season best practice – organize and label all of your tri gear that you won’t use until next spring/summer. You will thank yourself later so you don’t have to buy a new race belt for the 19th time. 

Jim: End of the season - check out the sale prices on gear you want for next summer! What better way to celebrate your off season but with a little retail therapy.

Article/movie/podcast rec of the week:

SWAP podcast on David Roche at Leadville 100. Key themes:

  • Adversity during race week and training cycle won’t necessarily kill your race 

  • Major self belief (bolstered by his wife and coach Megan’s belief in him)

  • Quality over quantity training (lower mileage than many peers in the sport) 

  • Fueling drives performance. ~120-140 grams of carbs per hour.

Gear Pick of the week: 

Katie: Fins! Endless entertainment in the pool

Jim: Peacock subscription to watch (and re-watch) Olympics, Tour de France (Men’s and Women’s race) and Vuelta a España and of course, The Office.  Winter inspiration!