top of page

No Spin? No Swim? No Problem.

Updated: Apr 3, 2020

Don't worry, if your swimming pool or spin class is closed in light of the current pandemic there are always alternatives to maintain those gains you have worked hard to achieve.

In this blog entry we look at the body's energy systems, how these relate to exercise duration and intensity and, armed with this knowledge, how you can easily swap out one form of exercise for another to achieve the same aims; or perhaps identify a change is needed to your current program.

The Science Bit (I'll keep it short)

Energy. We need it but where does it come from? For this our body turns to the magic of ATP (adenosine triphosphate), the molecule that provides the energy to our muscles to keep us moving.

The key question is, how does our body create ATP?

Personally, the answer to this question was a game changer in how I viewed different forms of exercise and how, depending on your intended exercise aims, you should train for superior performance.

"the answer to this question was a game changer [for me]"

So, the [highly simplified] Answer:

The body converts fuel sources (carbs, proteins and fats) using three different energy systems:

System 1: Immediate (Anaerobic Creatine Phosphate)

Doesn't need oxygen and can act immediately when there is a sudden need for energy however is exhausted very quickly, lasting up to circa 10 seconds. Think explosive, sudden or immediate movements.

System 2: Short-Term (Anaerobic Alactic)

Again this system doesn't require oxygen instead using glucose. Similarly to the immediate system, it is not overly efficient and exhausts quickly, within 60-120 seconds. To visualise this system in operation think about continuous muscular contractions as you perform several repetitions in the gym.

System 3: Long Term (Aerobic)

This is the system most of us have heard of and is dominant at intensities lasting longer than 2 to 3 minutes and is incredibly efficient in producing ATP. It's dominant at low to moderate intensity exercise and at higher intensities lasting longer than 2 minutes, however at higher intensities it works in tandem with the short-term system to match energy requirements to production. Think long distance running at talking pace or a 15 minute cycle sprint.

Practical Application - Aerobic Exercise

So, the burning question, if I can't swim or spin, what can I do?

Bringing everything together we can set some general parameters relating to:

  • Type

  • Duration

  • Intensity


This one is is easy and there seems a near endless list of exercise alternatives, running, cycling, skipping, rowing, stair climbing etc.

Duration and Intensity

These two parameters are very much interlinked so I have grouped them together.

Long Duration/Low Intensity:

The real sweet spot for focused aerobic training. In terms of duration we are looking at longer than 15 minutes of continuous exercise at a low intensity where you can still comfortably have a conversation but you are slightly out of breath.

"The real sweet spot for focused aerobic training"

Examples may be a 30 minute jog around the park or a moderately paced cycle ride in one single interval i.e. no stopping and starting. If this is the type of exercise you aim to improve then training 3 to 5 times per week, with 6 to 36 hours recovery between training sessions is a good general rule for your programming.

Shorter Duration/Higher Intensity (The Timesaver):

It's understandable that not all of us have the time to go on long runs or cycle rides for hours on end. As an alternative there is the option of short, interval based training at moderate to high levels of intensity. The level of intensity does mean that both the aerobic and alactic systems work together to ensure energy production meets demand, so it is not as focused, but is still an effective way to train both systems.

"Still an effective way to train both [aerobic and alactic] systems"

  • Option 1 Moderate to Higher Intensity: Here we opt for just 1 continuous interval between 10 to 30 minutes. Think a 10 minute sprint, or a 30 minute faced pace run.

  • Option 2 High Intensity Interval Training: Here we opt for 2 to 10 repetitions lasting 2 to 10 minutes each (i.e. a workout that could, theoretically, last between 4 minutes up to 100 minutes). It's important to rest between intervals, a general rule here is 50%, 100% or 150% of the interval time. For example you could perform a 2 minute interval and choose to program a rest of 1 minute, 2 minutes or 2.5 minutes depending on how efficient you are in recovery.

If this is the type of exercise you aim to improve then training 1 to 2 times per week, with 24 to 48 hours recovery between training sessions is a good general rule for your programming.

Measuring Intensity

So intensity has been mentioned a lot already and it's clearly important but how do we measure it? In-line with keeping things simple I include two commonly used, albeit limited, methods:

Maximal Heart Rate: If you are lucky enough to own a real-time heart rate monitor then using your maximal heart rate is a great way to compare your current heart rate to determine the intensity of your current activity.

Firstly, to calculate your maximal heart rate, a simple but effective equation is to subtract your age from 220. For example, if you are 30 years old your maximal heart rate would be 190bpm.

Now that you know your maximal heart rate we can allocate percentage brackets to determine intensity. The YMCASD has provided an easy to read graphic to make sense of this, see below.

Source: YMCASD

Rate of Perceived Exertion: The second option is to listen to your body and use some general cues to determine how much effort you are exerting. Personally I tend to use the Borg scale, see below, rating exertion from 6 to 20. I find it simple to understand and, similary to maximal heart rate, if you multiply the ratings by 10, you can also use it as a general heart rate guide e.g. somewhat hard exercise would see your heart rate hover around 130bpm.


In summary, there are several ways we can train to maintain or seek gains in aerobic efficiency. What's important is to choose a type of exercise that you like and program correctly to ensure you are challenging them in the right way to maintain or promote adaptations.

If you would like further guidance on training and programming feel free to reach out to me, Bruce Maidment, directly using my contact details found on our home page.

Happy Exercising

Please note: Before undertaking any exercise you should always consult a qualified health professional. The information provided in this blog entry is purely informative.

53 views0 comments

Recent Posts

See All


bottom of page