Don’t Hold Back On Your Exercise Regime!
Friday, 07 September 2018
Contributed by Asst Prof Yang Yifan, Physical Education & Sports Science Academic Group
New findings in a landmark study by Physical Education & Sports Science Academic Group on resistance training recovery period debunk the popular belief that at least 48 hours of recovery period is required for the body to achieve optimal results from intense exercises, calling for a serious review of physical activity guidelines as well as the prescription of routine blood tests after strenuous activities.
Health authorities worldwide, such as the American College of Sports Medicine (ACSM; Garber et al., 2011) and World Health Organization (World Health Organization, 2010), recognise that individuals, including those with chronic conditions like cancer and diabetes, can reap health benefits by undergoing resistance training two to three times a week.
The recommendation is to perform the sessions at least 48 hours apart to optimise molecular responses favourable to improvement in strength and muscle size (Garber et al., 2011). The basis for this recommendation is the results of two separate studies that demonstrated an optimal recovery period of 48 to 72 hours between resistance training sessions to promote strength and muscular development following two bouts of isometric contractions using electrical stimulation on rats (Haddad and Adams, 2002) and humans (Bickel et al., 2005).
Today, a 48-hour rest period between intense training has become a standard advice by trainers and doctors alike. However, consecutive days of resistance training over several days remains a common practice among competitive athletes, fitness enthusiasts and timestrapped weekend warriors. In fact, several studies on daily squatting (Zourdos et al., 2016) and elbow flexing (Dankel et al., 2017) showed significant increase in muscle thickness, suggesting that prolonged consecutive days of resistance training could improve muscle strength and size in professional athletes.
It is also unclear how the recovery period of resistance training affects many other physiological factors, like red blood cells (RBC). While it is important to conduct acute and chronic studies to differentiate between exercise-induced and pathological changes in RBC, such studies are relatively scarce, with often conflicting results (Schobersberger et al., 1990; McCarthy et al., 1997; Kilgore et al., 2002; Ahmadizad and El-Sayed, 2005; Ahmadizad et al., 2006; Craig et al., 2008; Hu et al., 2008; Cakir-Atabek et al., 2009; Hulmi et al., 2010; Kilic-Toprak et al., 2012; Teixeira et al., 2014), and there were even fewer studies on the effects of multiple bouts of resistance training in relation with the recovery period.
In 2016, the PESS research team, comprising Asst Prof Yang Yifan, Bay Pang Boon, Wang Yongtai Raymond, Dr Goh Jorming, Huang Junli and Hilary Teo Wei Jian, conducted a 12 weeks study to investigate the strength, body composition, and haematological changes of 30 young and healthy participants who underwent three days per week of consecutive (24 hours between sessions) or non-consecutive resistance (48 to 72 hours between sessions).
The findings from the study refuted current recommendation to space resistance training sessions at least 48 hours apart to optimise muscle and strength gain. There was no difference in muscle and strength gains between consecutive and non-consecutive days of resistance training after 12 weeks. Changes in RBC were similar too between the two training regimes. The good news for avid exercise fanatics and weekend warriors is that they can afford tighter training regimes without compromising their training outcomes.
Another important finding was that multiple bouts of strenuous resistance training could temporarily induce out-of-range values in RBC parameters in otherwise healthy individuals. This implied that RBC parameters should not be tested as part of a health screening for at least 48 hours after strenuous physical activities to avoid false positive readings.
This article was first published in the September 2018 issue of NIE’s quarterly newsletter, NIEWS. Click here to read more.