Strength training is one of the most important things you can do to offset the effects of the aging process. But, at any given heart rate you achieve during strength training, you'll be taking in and using a lot less oxygen than if you achieved that same heart rate while doing cardio activity, some research suggests the difference could be as much as 70%.
As lung capacity is something that declines as part of the aging process, it's important that you train to offset this as much as possible if you want to stay as energetic as possible at all life stages.
Low intensity cardio vs high intensity cardio:
Despite what much fitness marketing would have you believe you can train to improve your lung capacity using high OR low intensity training, but it's important to understand the differences between how you should conduct them.
If you are using a low intensity activity such as walking to improve your fitness, you'll need to do more of it or for longer durations than if you were using a higher intensity form of exercise. This requires a higher time commitment, but is often more comfortable and you're less likely to suffer from burnout as long as you build your duration slowly. If you've previously been inactive, have a health check prior to starting and build up slowly and gradually.
If you're using high intensity cardio methods, you should only do so if you've built yourself up over time to be able to tolerate the muscular, cardiovascular and joint demands. Don't jump straight into high intensity cardio. The time demands in terms of frequency and duration are lower with high intensity methods, but they tend to be a lot more uncomfortable if they are going to be effective. Higher intensity training works for those who are fit and healthy enough to tolerate it, it can be fun and can give you a sense of achievement. However, it’s very easy to burn out or suffer overtraining if you do too much of this type of training-that intensity comes at a physical cost which must be respected-take your recovery time seriously.
My cardio routine:
What do I do? I mix it up. I do a longer, slower paced session, and a shorter, higher intensity session each week in addition to my strength training. I keep active between workouts with walking too and will mix in a basketball session here and there! The type of workout you do should be modified to your energy levels and what’s going on in your life at the time. Burning the candle at both ends won't make you fitter, it’ll break you down. I help my clients learn to understand what type of activity is best for the life situations they may find themselves in (for example high stress or low stress days/weeks).
I have a long history of fitness and sporting activities so can afford to transition between low intensity and high intensity workouts, as my body is used to them. If you're starting out, always start easy and take your time with it, and when in doubt, seek professional advice.
Steve Shreeve (Updated October 2021).