Cardiorespiratory Fitness: Survival Of The Fittest

Cardiorespiratory fitness, which can be effectively measured in the clinic (VO2max), is associated with mortality and, hence, longevity.  Physical exercise that enhances such fitness may aid in promoting longevity, not yet at the point to “extend the genetically fixed lifespan” but to at least make the most out of what that (currently) fixed lifespan is.  Abstract:

Cardiorespiratory fitness, as measured by maximal oxygen uptake (VO2max), is related to functional capacity and human performance and has been shown to be a strong and independent predictor of all-cause and disease-specific mortality. The purpose of this review is to emphasize age-related physiological adaptations occurring with regular exercise training, with specific reference to the main organs (lung, heart, skeletal muscles) involved in oxygen delivery and utilization as well as the importance of exercise training for promoting life expectancy in clinically referred populations. As yet, it is not possible to extend the genetically fixed lifespan with regular exercise training, but to give the years more life. This is where physical fitness plays an important role.

Resistance Training For COPD

Aerobic exercise seems to be helpful for chronic obstructive pulmonary disease (COPD). Does resistance training also help? Here is a study, abstract:

OBJECTIVE: Emerging research suggests that aerobic-based physical activity may help to promote survival among chronic obstructive pulmonary disease patients. However, the extent to which engagement in resistance training on survival among chronic obstructive pulmonary disease patients is relatively unknown. Therefore, the purpose of this study was to examine the independent associations of muscle strengthening activities on all-cause mortality among a national sample of U.S. adults with chronic obstructive pulmonary disease. We hypothesize that muscle strengthening activities will be inversely associated with all-cause mortality.
METHODS: Data from the 2003-2006 NHANES were employed, with follow-up through 2011. Aerobic-based physical activity was objectively measured via accelerometry, muscle strengthening activities engagement was assessed via self-report, and chronic obstructive pulmonary disease was assessed via physician-diagnosis.
RESULTS: Analysis included 385 adults (20 + yrs) with chronic obstructive pulmonary disease, who represent 13.3 million chronic obstructive pulmonary disease patients in the USA. The median follow-up period was 78 months (IQR=64-90), with 82 chronic obstructive pulmonary disease patients dying during this period. For a two muscle strengthening activity sessions/week increase (consistent with national guidelines), chronic obstructive pulmonary disease patients had a 29% reduced risk of all-cause mortality (HR=0.71; 95% CI: 0.51-0.99; P = 0.04).
CONCLUSION: Participation in muscle strengthening activities, independent of aerobic-based physical activity and other potential confounders, is associated with greater survival among chronic obstructive pulmonary disease patients.

So, yes, it seems like resistance training is helpful. COPD patients, when discussing treatment plans with their physicians, should ask about resistance training if the physician does not bring it up themselves. One possibility is that a combination of aerobic and resistance training is best. Generally speaking, over the past few decades, increasing evidence is accumulating that resistance training is helpful for many aspects of health. I can remember “the old days” in which medical authorities recommended aerobic exercise only, and resistance training was viewed as something for “weird bodybuilders,” but today more informed medical professionals and other experts promote the benefits of resistance training.

Health Benefits Of Swimming

By Jmex60 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4611001

Swimming has been studied and has been shown to be effective for cardiovascular fitness and for enhancing body composition.  I’m not into swing myself, and get exercise through other approaches, but for those who do it, it’s obviously beneficial.  Always be safety-aware in the water, and don’t start a swimming program without first consulting with your physician.  Abstract:

BACKGROUND:Swimming is a popular and potentially health-enhancing exercise, but has received less scientific attention compared with other exercise modes.OBJECTIVE:The objective of the study was to determine the chronic (long-term) effect of pool swim training on physiological outcomes in non-elite or non-competitive swimming participants.DESIGN:This study was a systematic review with a meta-analysis.DATA SOURCES:We searched the electronic databases PubMed, EMBASE and CENTRAL from inception to March 2017.ELIGIBILITY CRITERIA:The eligibility criteria included randomised controlled trials, quasi-randomised controlled trials and controlled trials of chronic (long-term) swimming interventions in non-elite or non-competitive swimming participants, with a physiological outcome measure.RESULTS:Our search of 6712 records revealed 29 eligible studies. Swimming had a significant and clinically meaningful effect on maximal oxygen uptake compared with the control in an analysis including multiple populations (mean difference 6.32 mL/kg/min; 95% confidence interval 4.33-8.31), and subgroup analyses of healthy children/adolescents (mean difference 7.93 mL/kg/min; 95% confidence interval 3.31-12.55) and those with asthma (mean difference 9.67 mL/kg/min; 95% confidence interval 5.84-13.51) and healthy adults (mean difference 5.87 mL/kg/min; 95% confidence interval 2.93-8.81). Swimming also resulted in significant improvements in other cardiorespiratory fitness-related outcomes such as maximal minute ventilation (mean difference 0.61 L/min; 95% confidence interval 0.17-1.05), submaximal exercise performance (standardised mean difference 0.64; 95% confidence interval 0.14-1.13) and total exercise test time (mean difference 4.27 min; 95% confidence interval 2.11-6.42). Compared with the control, swimming had significant favourable effects on body mass (mean difference - 2.90 kg, 95% confidence interval - 5.02 to - 0.78), body fat percentage in multiple populations (mean difference - 1.92%; 95% confidence interval - 3.25 to - 0.60) and healthy children/adolescents (mean difference - 1.92%; 95% confidence interval - 4.64 to - 0.80) and lean mass (mean difference 1.96 kg; 95% confidence interval 0.21-3.71), but negative effects on waist circumference in a pooled analysis of two studies involving adults with hypertension (mean difference 4.03 cm; 95% confidence interval 2.58-5.49). Regarding lung function, significant effects of swimming vs. the control were found only for peak expiratory volume in analyses including children/adolescents combined with healthy adults (mean difference 58.74 L/min; 95% confidence interval 29.70-87.78) and children/adolescents with asthma alone (mean difference 63.49 L/min; 95% confidence interval 25.01-101.97). Based on limited data, swimming had similar effects to other exercise modes, except for higher post-intervention body mass index values with swimming vs. running in healthy adults (mean difference 1.18 kg/m2; 95% confidence interval 0.54-1.81).CONCLUSIONS:Swimming may offer robust beneficial effects on cardiorespiratory fitness and body composition across multiple populations and effects may be comparable to other exercise modes. Future randomised controlled trials are required to establish the effectiveness of swimming on physiological outcomes in healthy populations and those with non-communicable disease.

Low Carb Ironman Training?

One possible way to overcome carbohydrate (carb) storage limitations for extreme duration athletic events like Ironman triathlons is for the athlete to train under a low-carb diet, to get the body acclimated to that condition, and then giving carb supplementation during the completion, providing the levels that the now-adjusted body can utilize.  Keep in mind that another study, looking at elite race walkers (somewhat less extreme that the Ironman) found that low carb diets were negative for performance.  So the current finding (abstract below) may apply only to the most extreme events where “carb loading is inefficient?  More study is required.

Ironman triathlons are ultra-endurance events of extreme duration. The performance level of those competing varies dramatically, with elite competitors finishing in ~ 8:00:00, and lower performing amateurs finishing in ~ 14-15:00:00. When applying appropriate values for swimming, cycling and running economies to these performance times, it is demonstrated that the absolute energy cost of these events is high, and the rate of energy expenditure increases in proportion with the athlete's competitive level. Given the finite human capacity for endogenous carbohydrate storage, minimising the endogenous carbohydrate cost associated with performing exercise at competitive intensities should be a goal of Ironman preparation. A range of strategies exist that may help to achieve this goal, including, but not limited to, adoption of a low-carbohydrate diet, exogenous carbohydrate supplementation and periodised training with low carbohydrate availability. Given the diverse metabolic stimuli evoked by Ironman triathlons at different performance levels, it is proposed that the performance level of the Ironman triathlete is considered when adopting metabolic strategies to minimise the endogenous carbohydrate cost associated with exercise at competitive intensities. Specifically, periodised training with low carbohydrate availability combined with exogenous carbohydrate supplementation during competition might be most appropriate for elite and top-amateur Ironman triathletes who elicit very high rates of energy expenditure. Conversely, the adoption of a low-carbohydrate or ketogenic diet might be appropriate for some lower performance amateurs (> 12 h), in whom associated high rates of fat oxidation may be almost completely sufficient to match the energy demands required.

Exercise Sequence And Fitness

Strength, in this case lower body strength, is maximized by first training for strength followed by training for endurance (rather than the other way around) – which makes sense. For aerobic fitness, training order doesn’t matter, so the net conclusion one can make is to train for strength and then endurance when scheduling sequential training sessions. Abstract:

We conducted a systematic literature review and meta-analysis to assess the chronic effects of the sequence of concurrent strength and endurance training on selected important physiological and performance parameters, namely lower body 1 repetition maximum (1RM) and maximal aerobic capacity (VO2max/peak). Based on predetermined eligibility criteria, chronic effect trials, comparing strength-endurance (SE) with endurance-strength (ES) training sequence in the same session were included. Data on effect sizes, sample size and SD as well other related study characteristics were extracted. The effect sizes were pooled using, Fixed or Random effect models as per level of heterogeneity between studies and a further sensitivity analyses was carried out using Inverse Variance Heterogeneity (IVHet) models to adjust for potential bias due to heterogeneity. Lower body 1RM was significantly higher when strength training preceded endurance with a pooled mean change of 3.96 kg (95%CI: 0.81 to 7.10 kg). However, the training sequence had no impact on aerobic capacity with a pooled mean difference of 0.39 ml.kg.min-1 (95%CI: -1.03 to 1.81 ml.kg.min-1). Sequencing strength training prior to endurance in concurrent training appears to be beneficial for lower body strength adaptations, while the improvement of aerobic capacity is not affected by training order.

Exercise For Peripheral Artery Disease

Perhaps we should not be surprised by the findings reported in this paper: exercise alone, but not a sophisticated new treatment (granulocyte-macrophage colony-stimulating factor) was helpful for patients with lower extremity peripheral artery disease.  There is a lesion there I think for people paying attention. Abstract:

IMPORTANCE:Benefits of granulocyte-macrophage colony-stimulating factor (GM-CSF) for improving walking ability in people with lower extremity peripheral artery disease (PAD) are unclear. Walking exercise may augment the effects of GM-CSF in PAD, since exercise-induced ischemia enhances progenitor cell release and may promote progenitor cell homing to ischemic calf muscle.OBJECTIVES:To determine whether GM-CSF combined with supervised treadmill exercise improves 6-minute walk distance, compared with exercise alone and compared with GM-CSF alone; to determine whether GM-CSF alone improves 6-minute walk more than placebo and whether exercise improves 6-minute walk more than an attention control intervention.DESIGN, SETTING, AND PARTICIPANTS:Randomized clinical trial with 2 × 2 factorial design. Participants were identified from the Chicago metropolitan area and randomized between January 6, 2012, and December 22, 2016, to 1 of 4 groups: supervised exercise + GM-CSF (exercise + GM-CSF) (n = 53), supervised exercise + placebo (exercise alone) (n = 53), attention control  + GM-CSF (GM-CSF alone) (n = 53), attention control + placebo (n = 51). The final follow-up visit was on August 15, 2017.INTERVENTIONS:Supervised exercise consisted of treadmill exercise 3 times weekly for 6 months. The attention control consisted of weekly educational lectures by clinicians for 6 months. GM-CSF (250 μg/m2/d) or placebo were administered subcutaneously (double-blinded) 3 times/wk for the first 2 weeks of the intervention.MAIN OUTCOMES AND MEASURES:The primary outcome was change in 6-minute walk distance at 12-week follow-up (minimum clinically important difference, 20 m). P values were adjusted based on the Hochberg step-up method.RESULTS:Of 827 persons evaluated, 210 participants with PAD were randomized (mean age, 67.0 [SD, 8.6] years; 141 [67%] black, 82 [39%] women). One hundred ninety-five (93%) completed 12-week follow-up. At 12-week follow-up, exercise + GM-CSF did not significantly improve 6-minute walk distance more than exercise alone (mean difference, -6.3 m [95% CI, -30.2 to +17.6]; P = .61) or more than GM-CSF alone (mean difference, +28.7 m [95% CI, +5.1 to +52.3]; Hochberg-adjusted P = .052). GM-CSF alone did not improve 6-minute walk more than attention control + placebo (mean difference, -1.4 m [95% CI, -25.2 to +22.4]; P = .91). Exercise alone improved 6-minute walk compared with attention control + placebo (mean difference, +33.6 m [95% CI, +9.4 to +57.7]; Hochberg-adjusted P = .02).CONCLUSIONS AND RELEVANCE:Among patients with PAD, supervised treadmill exercise significantly improved 6-minute walk distance compared with attention control + placebo, whereas GM-CSF did not significantly improve walking performance, either when used alone or when combined with supervised treadmill exercise. These results confirm the benefits of exercise but do not support using GM-CSF to treat walking impairment in patients with PAD.

My Knee Pain

Blausen.com staff. "Blausen gallery 2014". Wikiversity Journal of Medicine.

For many years I had chronic on-and-off pain in my left knee, accompanied by cracking sounds, which probably was due to me doing front squats with bad form (bouncing, leaning forward) when I was younger.  While sometimes I would feel nothing, other times the pain would be moderately severe, particularly when walking up and down stairs, or doing squats.

The pain is now 99% gone, very, very rarely, maybe once every 4-6 months, I’ll get a very brief and weak twinge – I honestly cannot remember the last time it happened.  I can now do squats (proper form of course) without any pain. 

The pain went away after I started increasing certain activities – walking, walking up stairs (sometimes two at a time) quickly at work as part of cardiovascular fitness, jumping rope, etc.  I believe these activities strengthened certain muscles around the knee, helping to stabilize it, and perhaps correcting some muscle imbalances there.  Now, most likely, whatever damage I had there was slight, and perhaps exacerbated by an imbalance, so that this exercise regimen – done for cardiovascular fitness not with any prior intent to help the knee – had the side effect of helping with the knee problem. 

Other people may have more severe damage and so the activities I did may make them worse; of course, always consult with your physician.  Some people may require surgery if they have serious damage.  I’m just reporting that what I did, helped.

Two Types of Exercise

How much aerobic exercise is required for fitness?  I agree with the consensus, at least 30 minutes of walking per day is good for you. If the weather is good, do it outside, if possible. In periods of bad weather, I'll walk for 30 minutes inside the house, watching TV, listening to a podcast, or just thinking about things. get those 30 minutes or so. I'll do some bursts of jumping rope a several days a week, and, at work, climb stairs (usually two at a time), to get some aerobic exercise.

Anaerobic exercise is important as well. Doing some weightlifting work, twice a week, works for me. Every once in a while, take a break from the weights to let body and mind recover, and then start the next cycle.

This combination of aerobic and anaerobic exercise, coupled to a healthy diet, will work wonders. An improved diet (a topic of other posts here) and regular exercise has reduced my blood pressure (having one of those use-at-home blood pressure and heart rate units for home monitoring is a good idea).