I am writing this in response to the many conversations I have been having with the 50 and older guys, and some of the not so old women, in my riding groups with regard to doing interval training on the bicycle; apparently many of us just don’t do them. We do long rides to build endurance and we climb hills, and we do intervals on our group rides when someone else is setting a fast pace, but we typically don’t go out and do our own interval work. A lot of it comes down to time, having to try and fit in yet another ride into our week, but also a lot comes down to people really don’t know what kind of intervals to do, their duration, the intensity level, and the frequency. Hopefully this primer will provide enough answers so that you can add intervals to your workouts.

Truthfully the start of this conversation dates back a couple years ago when Joe Friel, the author of many of the “training bibles” for triathletes and cyclists, turned 69 years old and spent the year researching and writing about aging for older athletes to try and understand the physiological changes he (and his older clients), were going through and how they could reshape their training to get the most bang for the buck. In the end he approached his publishing company and together they put out a new book, Fast after 50, which I highly recommend to anyone over that age. Actually, if you’re in your 40’s the information is very relevant and a precursor for what to expect when you age up.

I’ll spare you the details but share these three facts that he says are the performance related changes that every aging athlete encounters:

• A decrease in aerobic capacity, i.e., your ability to go really really fast and bring in enough oxygen to support it, as your VO2 max drops
• An increase in body fat (sorry, that’s just how our bodies are wired!)
• A decrease in muscle mass, another sad effect of our bodies increasing inability to rebuild our muscles and bones to the same level as when we were younger

So in the end these are what everyone has to look forward to, our three big limiters. Given that, what kind of exercises should we be doing? Well, the typical path is that we start training slower as it hurts more to go long and hard, so we focus on more aerobic training efforts, which according to Friel is fine, if you don’t mind getting slower.

But what if you want to continue to race as fast as your body will allow? How about you start with a change to your mindset, where maybe long and fast isn’t in the picture anymore, but what about short and fast, can we do that? His answer is a definite YES, and his solution is for older athletes to refocus on shorter and harder efforts, wary of the side effects of doing too much with our older bodies, but with enough direction and monitoring, it is definitely something we can do.

As far as the proper direction and monitoring, Friel includes three tables in his book that define:

1. Suggested training details for low, moderate, and high “dose” workouts, specific to the different workout types (Aerobic-capacity intervals, Lactate-threshold intervals, Aerobic threshold, and weight lifting)
2. A definition of the strength training phases for senior endurance athletes (which honestly can be applied to anyone over the age of 35!)
3. Priorities of workout types according to the race duration of your key races and the seasonal periods for senior athletes

These three tables define the what, why, and when information everyone needs to build a seasonal, periodized training program. If you’re not familiar with Friel’s writings you may need to dig deeper, but I was able to apply this information to write training plans this year for two of my friends and training partners, Joe and Cindy. Both have long years of training experience and really just needed tweaking to get in the hard workouts they needed in each training block to help them reach their goals for the year. I used Friel’s ideas to create more detailed daily training workouts to benefit each of them.

But for this blog I only wanted to focus on the first item from above; suggested interval training sets that anyone can add to a bike workout on a weekly basis. The focus will be on the “dose”, meaning volume (time), frequency (repetitions), and intensity (Power Level based on your Functional Threshold Power, FTP, HR training zone, or Perceived Exertion level, PE.)

The dose will be broken into two groups, Low to Moderate and Moderate to High, to make it simple. If you have never done intervals on the bike, are currently out of shape, or haven’t done them in a while then I would suggest starting with the Low to Moderate dosage sets, repeating them 2-3 times each to find your sweet spot in your Power/HR/PE level, before moving on to the longer intervals. Once you’ve done that, and this will take some time, and you feel like your strength and adaptation have gone well, only then should you move on to the Moderate to High dosage sets. Of course if you’re training is good and you’re familiar with interval work on the bike, start with the harder sets and move on at your own discretion.

Ideally you want to work up to around 20-25 minutes total time of hard intervals during each workout, starting with a 15-20 minute warm up, including some high cadence work to elevate your HR and get your legs ready to go, then the intervals, with almost always an equal amount of rest, and then the final cool down. These should be done on a relatively flat surface, so not on big hills as they skew your power up too high. Interval work is about working hard in the flats against the wind, not against gravity on a hill.

As far as how hard you should go, your intensity level, follow these guidelines:

• If you’re using a power meter, on intervals from 1.5-3 min. long, start out around your FTP+20% to see if you can hold that power for the whole time, for all the repetitions, and then adjust accordingly on subsequent weeks. For intervals longer than that start out around your FTP+10% and adjust up or down as needed. The 10 min. intervals will be around FTP+5%, plus or minus. And note, I have my 3 second Power and average power on my bike computer’s display, focusing on the average power once I’m rolling to avoid going to hard or slowing down.
  • If you don’t know your FTP then use your HR or PE as follows to try and establish what it is, or better yet, before you add intervals to your training plan, go out and establish your FTP first.
• If HR is your thing, then you already know that when doing intervals HR lags relative to your effort, therefore you need to start out strong but not over the top strong, getting your HR up to your Anaerobic Threshold (AT) pretty soon on the shorter intervals and not quite as fast on the longer ones else you’ll blow up and have to slow down. Average HR here is almost useless for short intervals, although on intervals > 5 min. it can start to be used as a guide to your level of effort.
• And finally, if PE is what you rely on, these should start out hard and move towards feeling very hard, say 7.5-8 on a 10 point scale, finishing at 8-9.

Aerobic Capacity Intervals
Low to Moderate Dose	Moderate to High Dose
10 x 1.5 min (1.5 min recoveries)	10 x 2 min (2 min recoveries)
8 x 2 min (2 min recoveries)	8 x 3 min (3 min recoveries)
6 x 3 min (3 min recoveries)	6 x 4 min (4 min recoveries)
4 x 5 min (4 min recoveries)	5 x 5 min (4 min recoveries)
2 x 8 min (6 min recoveries)	2 x 10 min (8 min recoveries)

I think the sets are self-explanatory, but if not please do not hesitate to contact me with any questions. I think everyone should start with the shorter intervals, really work on establishing the correct pacing from the start, and then commit to holding your pace and intensity level throughout. Within a very short period of time you’ll be feeling the results, and as one of the riders told me this morning after doing the 8 x 2 min. intervals on the trainer this past week (and the trainer is an excellent place to do these kind of sets!), “I hate you Fred!”, so I guess the set had the desired results, OUCH! Of course I know next time she’ll be better prepared, will try to go harder, and then will probably tell me the same thing!

Once you’ve done the first 3-4 variations in the set feel free to pick the one or two that you prefer to suit your style or maybe the one that fits better within your training and racing season. The 8 and 10 minute intervals are really good to do before upcoming races as you have to suffer longer to complete them which builds your mental confidence come race day, knowing that you can hold the power on longer than you thought.

And just so you know that I feel your pain when I suggest these things, I also started following Friel’s advice starting last year to reinvigorate my own training plans, having slipped into the longer and slower workouts without any high aerobic or anaerobic workouts at all. Having lost muscle tone and weight (fat is lighter than muscles), I started with shorter and harder hill work on the run, moving on to a season of track workouts, which I was coaching for our local tri club, so I basically had them run the sets I needed to get faster, and in turn so did they.

I modified my strength training based on the book to include more low rep, high weight sets, after the appropriate amount of adaptation time, which in turn helped me put on a few more pounds, hopefully all muscle. I have just recently added power-based interval work on the bike and I am already seeing that my old FTP is out of date as my power numbers are climbing. Of course I realize that I am a science experiment with only one participant, so as always your results may vary, but I think if you give these sets the chance to do their work, then you too will reap the benefits.

Intervals can be done by yourself or even in a group, but it’s best if doing them in a group to let others know your plan so they can work with you. Truthfully group rides are best for longer intervals “as a group”, and these short and hard intervals are best done solo, just you against the clock. Enjoy!