What is better, harder or easier?

Question

I am 83 years old. My doctor said that I walk for 40 minutes 3 to 4 times a week. I bought stationary bike. What is better, 40 minutes level one resistance or 20 minutes level 2 resistance?

Answer 1

Plenty of ways to approach fitness, but if your doctor has specified 40 minutes of low intensity work, I'd lean toward that.

In the running world, plenty of elite runners are doing most of their training at low intensity, with just a little bit of higher intensity, so don't get sucked into the idea that working harder is "better". It probably isn't. Ref: https://www.outsideonline.com/health/training-performance/norwegian-method-jakob-ingebrigtsen/ Generally, google "ingebrigtsen training".

Answer 2

It depends on what you're trying to achieve. If you're going for overall health (which I assume you are, as an 83 year old) then more time at a lower intensity is going to be preferable.

If you're going for increased maximum output, then you need to push your limits at least sometimes or your body won't adapt. Note though that even long distance runners to the majority of their training at a low intensity, I think about 80:20 low intensity to high intensity.

A good rule of thumb to find the "sweet spot" is that you should be able to talk freely (without stopping for breath) while exercising, but with some difficulty.

Answer 3

Given your age and the information you've shared, a moderate level of training intensity would likely be the most suitable for you. This would correspond to about 40% to 50% of your maximum capability, so you might want to consider continuing with your 40 minutes of exercise on a level one resistance on your stationary bike, especially if this feels comfortable and sustainable for you.

You can check the intensity level e.g. by observing your breath. There should only be a slight increase in breath frequency and you should fell no urge to breathe faster.

The following explanations include "weight loss", which probably is not your goal, but weight loss and lipid oxidation are symptoms of a healthy training that is capable to improve mitochondrial and metabolic health.

This approach is supported by a body of research that has emerged in the last two decades, showing beneficial effects of moderate, low-intensity, low-volume exercise training. The STRRIDE studies (Studies of a Targeted Risk Reduction Intervention through Defined Exercise) have shown that this approach can have even more positive effects on fat deposits and insulin sensitivity than higher intensity exercise. This is largely due to the release of certain muscle metabolites such as succinate, which improves insulin sensitivity and is thought to counteract obesity and metabolic deterioration.

The benefits of this low-intensity exercise go beyond simple calorie burning. Exercise modifies the epigenetic state, inducing transcriptional changes via transient modifications in the bioavailability of metabolites, substrates, and cofactors. Lipid breakdown can generate short-chain molecules such as butyrate, which can regulate histone deacetylase [24]. Exercising muscle can also release bioactive substances known as myokines and myometabokines, which can have beneficial effects at the whole-body level.

Interestingly, a bout of low-intensity exercise, when performed at the beginning of the day, has been shown to increase lipid oxidation over the following 24 hours. This approach also appears to regulate eating behavior and reduce sedentarity-induced overeating.

So, based on this information, you might find that sticking to a 40-minute routine on a level one resistance on your stationary bike could provide you with the benefits you're looking for, without overstraining your body. As always, remember to consult with your doctor before making any significant changes to your exercise routine.