The answer to this question is ‘yes’ if you are exercising properly!
To maintain / improve fitness you should be aiming to challenge yourself from time to time. This means that you are ‘stressing’ your muscles. When you do this your body needs to repair the ‘damage’ caused and adjust to better cope with the challenge again.
If you undertake a ‘gentle’ exercise on a regular basis, doing the same and possibly with regular stretches / walking, then you may have no need for additional rest. However the danger then is your body adapts to the gentle movement and will no longer be able to undertake more vigorous exercise. So as a result you will actually become less fit. Arguably this is what some people consider as ‘getting older’ but it is often the result of moving less!
Extensive Research has shown that at any age it is possible to improve your strength and whilst this should involve some intense exercise, these only need to be undertaken twice a week. So if you push yourself a little – you also get the benefit of additional rest!
Furthermore, there is an issue of experiencing ‘chronic’ fatigue which is often experienced in people who undertake rigorous exercise most days without ensuring time for recovery. The effects of this can be extremely damaging and more importantly whilst someone may think they are doing more – they may suffer reduced strength and movement ability.
Recovery from intense exercise is likely to vary due to a range of other factors including sleep quality, nutrition, stress and hormones. So it is important to assess how you feel.
There is further evidence that even with built in rest, it is beneficial to also have one week every two months where you significantly reduce the intensity of your regular exercise – its called a ‘download week’. Many people experience improved ability after such a period!
So the main message is that rest and exercise go hand in hand to produce the greatest benefit!