By X. Derek. University of Massachusetts Medical School. 2017.
The %VO2max quality renagel 400mg, linked to the level of muscle-produced lactate in the blood, is a good indicator of the balance between aerobic and anaerobic meta- bolic needs of the exercising skeletal muscle (Christensen, 1931; Robinson, 1938; Astrand and Rhyming, 1954; Astrand, et al. It is such a balance that forms the basis of the intensity targets that are so widely recommended in the recognised guidelines mentioned earlier and to be discussed later in this chapter. The signiﬁcance of this contribution between aerobic and anaero- bic processes (Krogh and Lindhard, 1920) underpins the physiological effectiveness of the exercise session, both in determining the correct intensity and in achieving the required duration of the aerobic exercise session. The key aspect was the use of the differ- ence in heart rate between rest and maximal exertion, known as the heart rate reserve. Over a period of training, resting heart rate decreases, whereas maximal heart rate remains much the same; thus, the gap between rest and maximal heart rate increases. This formula accounts for the widening heart rate reserve over the weeks and months of exercise training. The result of this approach is that a given percentage of maximal heart rate reserve (%HRRmax) theoretically represents the same %VO2max, although a given %HRmax does not represent the same %VO2max, except near maximal aerobic exercise intensities, as illustrated in Figure 3. More recent recommendations by the ACSM (1998) have referred to a VO2 reserve method, where there is a matching of heart rate reserve and VO2 reserve (the difference between resting VO2 and VO2max). This method has further increased the accuracy of the link between heart rate and oxygen uptake in representing the work intensity of the exercising skeletal muscle (Swain and Leutholz, 1997). With any of the formulas, accuracy is dependent on the validity of the measured or estimated values. In this case both maximal heart rate and resting heart rate validity need to be considered. Measuring a true resting heart rate requires the patients to monitor themselves at home when they wake ﬁrst thing in the morning. Exercise Physiology and Monitoring of Exercise 51 100 90 80 70 60 50 %HRRmax %HRmax 40 30 20 10 0 100 %VO2max %VO2max <20 20–39 40–59 60–84 >85 100 %HRRmax <20 20–39 40–59 60–84 >85 100 %HRmax <35 35–54 55–69 70–89 >90 100 RPE <10 10–11 12–13 14–16 17–19 19–20 Figure 3. Summary of the relationship between the percentages of maximal aerobic power (%VO2max), maximal heart rate reserve (%HRRmax), maximal heart rate (%HRmax) and Borg’s rating of perceived exertion (RPE).
Negotiating between wheelchair and chair When your leg muscles are weak cheap 400mg renagel mastercard, and the neurological control of them is very damaged, moving from a seated to an upright position is often very difﬁcult. You may well need some professional advice and demonstration as to how best to accomplish this – possibly with aids, or someone who can help. As a general rule be sure you have any walking aid that you regularly use nearby, wear shoes, and always stand on a non-slip surface. The usual procedure to get up is to put your feet slightly apart and ﬂat on the ﬂoor, and then to pull them back a little towards the chair. Place both hands on the chair arms, and then ease yourself forward so that your bottom is near the front of the chair. You should then push down on your hands and heels, and straighten your hips and knees. When you move from a standing to a sitting position, the procedure is rather simpler, and involves turning round, so that you can feel the chair with the back of your legs. Of course, if you are getting in and out of a wheelchair, ensure that the chair is stable and that the wheelchair brakes are on! There are inﬂatable and portable cushions to help you rise from a chair, and there are also a number of mechanical aids, usually incorporated into the chairs themselves, that hydraulically assist the actions of sitting and standing – although these can be expensive. Bathroom aids Baths and showers Ensure that getting in and out of the bath is as safe and easy as possible and that, when you are in the bath, you can relax without worrying. Working out how to clean yourself properly is often a relatively minor problem compared to getting in and out of the bath! The siting of these is very important – consult your occupational therapist or other skilled person, to make sure that they can really help you. With a hand-held, temperature-controlled shower attachment, you should have a reasonably enjoyable experience, even if it isn’t quite the same for some people as a bath! Toilet aids Toiletting aids are important for, traditionally in our society, going to the toilet yourself is an indication of independence. Continuing to go to the toilet completely by yourself for as long as possible is an issue that many people feel strongly about, even between partners who have known each other for many years. Although having other people to assist you is a problem for both sexes, many men in particular are not so used to helping others with such issues on an everyday basis, such as young children or older parents, or indeed their partners.