Although I see nothing wrong with swim, bike, run for x-minutes (as I rarely go by miles with my training or my athletes training), I find the best way to train for quality is to have a purpose for each workout. You warm-up and cool down as needed and the focal point is the main set....the intervals.
When athletes or fitness enthusiasts think intervals they generally think hard, leg burning, sweaty and intense. But intervals can range from steady and long to short and intense...and everything in between.
Here are a few of my favorite, recent Ironman-focused swim, bike, run workouts:
Key IM bike workout
IM focused long brick
Breakthrough IM swim
But in addition to using intervals for cardio workouts, intervals work great for strength training. I am a firm believer that strength training should be included in the weekly fitness routine - regardless of what type of athlete or fitness enthusiast you are. I have been strength training since I was 11 (when I started swimming competitively) and I feel it has given me strong bones (along with dietary focus) and muscles which have kept me from experiencing any stress fractures or broken bones in my life thus far. I also feel that strength training is valuable to improving power, speed, endurance and form as an athlete or fitness enthusiast and helps minimize time spent training for cardio (ex. junk miles) as the body needs little time at home or in the weight room to gain strength whereas for cardio, physiological adaptations can often come rather slowly after the initial first 3-4 weeks of training.
Although full body strength training and plyometrics are ideal for the off-season and base phase for athletes, I believe that hip and core work should be continued year round. Certainly, as athletes, any type of "strength work" should enhance cardio and not sabotage us for upcoming workouts so there must be a nice balance as to when the strength training falls and what type of exercises are performed.
Here are a few of my favorite hip and core focused exercises which you can include as intervals into your weekly workout routine. Rather than focusing on reps, go by time. Seeing that for most people one side of the body is often weaker/stronger than the other, time-based intervals are ideal for hip and core work so that you can finish an interval with good form rather than just trying to get to a certain number of reps while the body is fatiguing with poor form.
Here are some of my favorite hip/core exercises:
Perform 3-4 days a week, 10-20 minutes.
Up to 30 - 90 seconds - on each side (if appropriate) or for each exercise.
-lying on side, top leg lifts (straight and bent leg)
-plank, belly down
-plank w/ one leg lifted (belly down)
-side plank (optional w/ top hip thrust)
-reverse crunch (if equipment bench is available) or reverse crunch on stability ball
-mason twists (optional w/ weight)
-lying on back, leg drops
So, to help you out with your interval "strength" work at home (or any type of intervals, especially for personal trainers or aerobic instructors), I have the perfect tool for you!
Gymboss contacted me and asked if I would review their interval timer stopwatch. I said absolutely as I am always interested in new technology that can make for better, smarter and more quality-focused workout. As much as I love to exercise, I think like an athlete and therefore, I want to adapt with the least amount of training stress. I do not want to waste my time exercising and not making performance gains. Just like you, I want to put in the work to receive the benefits and be able to do it all again (but better) the next day.
To learn more about the Gymboss you can check out the Operating tips video which gives a great explanation of all the wonderful features of this product. You do not have to use all the functions as it works just fine as a stop watch but for those who want to do the work and think very little, this will really help you out. All you have to do is set up the timer for your workout and it will automatically alert you as to when you should be performing an exercise and what you should stop and rest. It's like having a trainer with you but without the fun chatting in between intervals. :)
Enjoy! Any additional questions, send me an email and I'd be happy to help you out.