Second Wind Research Articles

Dose–response effect of pre-exercise carbohydrates under muscle glycogen unavailability: Insights from McArdle disease

BackgroundThis study aimed to determine the effect of different carbohydrate (CHO) doses on exercise capacity in patients with McArdle disease—the paradigm of “exercise intolerance”, characterized by complete muscle glycogen unavailability—and to determine whether higher exogenous glucose levels affect metabolic responses at the McArdle muscle cell (in vitro) level. MethodsPatients with McArdle disease (n = 8) and healthy controls (n = 9) underwent a 12-min submaximal cycling constant-load bout followed by a maximal ramp test 15 min after ingesting a non-caloric placebo. In a randomized, double-blinded, cross-over design, patients repeated the tests after consuming either 75 g or 150 g of CHO (glucose:fructose = 2:1). Cardiorespiratory, biochemical, perceptual, and electromyographic (EMG) variables were assessed. Additionally, glucose uptake and lactate appearance were studied in vitro in wild-type and McArdle mouse myotubes cultured with increasing glucose concentrations (0.35, 1.00, 4.50, and 10.00 g/L). ResultsCompared with controls, patients showed the “classical” second-wind phenomenon (after prior disproportionate tachycardia, myalgia, and excess electromyographic activity during submaximal exercise, all p < 0.05) and an impaired endurance exercise capacity (–51% ventilatory threshold and –55% peak power output, both p < 0.001). Regardless of the CHO dose (p < 0.05 for both doses compared with the placebo), CHO intake increased blood glucose and lactate levels, decreased fat oxidation rates, and attenuated the second wind in the patients. However, only the higher dose increased ventilatory threshold (+27%, p = 0.010) and peak power output (+18%, p = 0.007). In vitro analyses revealed no differences in lactate levels across glucose concentrations in wild-type myotubes, whereas a dose–response effect was observed in McArdle myotubes. ConclusionCHO intake exerts beneficial effects on exercise capacity in McArdle disease, a condition associated with total muscle glycogen unavailability. Some of these benefits are dose dependent.

English

English

Too Much, Too Fast, Too Novel: A Case of Rhabdomyolysis

Our patient is a 17-year-old Hispanic female with a past medical history of nephrolithiasis. She presented to clinic with bilateral thigh pain. 3 days prior to presentation she attended a cycling class that “required her to push herself”. Approximately 10 minutes into the exercise she “felt winded but then felt a second wind”. Immediately after the class the patient began to feel bilateral thigh pain that was constant, 10/10, did not radiate, and was exacerbated by walking, particularly painful walking downstairs, and any movement that requires bending at the …

T.P.28: The significance of clinical and laboratory features in the diagnosis of glycogen storage disease type V: A case report

Glycogen storage disease type V (GSD-V), also known as McArdle’s disease, is the most common disorder of muscle glycogenosis. Most adult patients present with typical clinical and laboratory features. However, there has only been one case report of Korean patients with GSD-V. Here, we report a Korean case of GSD-V with typical clinical and laboratory findings. A 32-year-old woman was referred to our clinic due to easy fatigability, muscle cramps and myoglobulinuria. Her family history was unremarkable. She recalled easy fatigability, muscle cramps and contractures after intense exercise during physical education classes since early adolescence. In addition, she had several episodes of dark urine following intense exercise such as long-distance running. She also reported marked improvement in exercise tolerance after about 20 min, a process termed the ‘second-wind phenomenon’; specifically, she had seen improvement in excessive fatigue, breathlessness, and tachycardia. Physical examination did not show any neurological abnormality, including fixed muscle weakness or atrophy. Serum creatine kinase level was 1161 IU/L at rest. The result of the non-ischemic forearm exercise test was compatible with GSD-V. Mutation analysis identified the compound heterozygous mutations of the PYGM, p.D510fs and p.F710del, which has not yet been reported in Korea. The present case recognizes that detail clinical and laboratory analysis is the first step in the diagnosis of GSD-V.

The “second wind” in McArdle's disease patients during a second bout of constant work rate submaximal exercise

Patients with McArdle's disease (McA) typically show the "second-wind" phenomenon, a sudden decrease in heart rate (HR) and an improved exercise tolerance occurring after a few minutes of exercise. In the present study, we investigated whether in McA a first bout of exercise determines a second wind during a second bout, separated by the first by a few minutes of recovery. Eight McA (44 ± 4 yr) and a control group of six mitochondrial myopathy patients (51 ± 6 yr) performed two repetitions (CWR1 and CWR2) of 6-min constant work rate exercise (∼50% of peak work rate) separated by 6-min (SHORT) or 18-min (LONG) recovery. Pulmonary O2 uptake (Vo2), HR, cardiac output, rates of perceived exertion, vastus lateralis oxygenation {changes in deoxygenated Hb and myoglobin Mb concentrations, Δ[deoxy(Hb+Mb)], by near-infrared spectroscopy} were determined. In McA, Vo2 (0.86 ± 0.2 vs. 0.95 ± 0.1 l/min), HR (113 ± 10 vs. 150 ± 13 beats/min), cardiac output (11.6 ± 0.6 vs. 15.0 ± 0.8 l/min), and rates of perceived exertion (11 ± 2 vs. 14 ± 3) were lower, whereas Δ[deoxy(Hb+Mb)] was higher (14.7 ± 2.3 vs. -0.1 ± 4.6%) in CWR2-SHORT vs. CWR1; the "overshoot" of Δ[deoxy(Hb+Mb)] and the "slow component" of Vo2 kinetics disappeared in CWR2-SHORT. No differences (vs. CWR1) were observed in McA during CWR2-LONG, or in mitochondrial myopathy patients during both CWR2-SHORT and -LONG. A second-wind phenomenon was observed in McA during the second of two consecutive 6-min constant-work rate submaximal exercises. The second wind was associated with changes of physiological variables, suggesting an enhanced skeletal muscle oxidative metabolism. The second wind was not described after a longer (18-min) recovery period.

The Significance of Clinical and Laboratory Features in the Diagnosis of Glycogen Storage Disease Type V: A Case Report

Glycogen storage disease type V (GSD-V) is the most common disorder of muscle glycogenosis with characteristic clinical and laboratory findings. A 32-yr-old woman complained of exercise intolerance and myoglobulinuria since early adolescence. She reported several episodes of second-wind phenomenon. Physical examination did not show any neurological abnormality, including fixed muscle weakness or atrophy. Serum creatine kinase level was 1,161 IU/L at rest. The result of the non-ischemic forearm exercise test was compatible with GSD-V. Mutation analysis identified the compound heterozygous mutations of the PYGM, p.D510fs and p.F710del, which has not yet been reported in Korea. The present case recognizes that detail clinical and laboratory analysis is the first step in the diagnosis of GSD-V.Graphical

A second wind fo' the president

A second wind fo' the president

A second wind for the president

A second wind for the president

ChemInform Abstract: Dehalogenative and Deprotonative Lithiation of Pyridines — A Second Wind for Trimethylsilylmethylithium (TmsCH2Li)

AbstractReview: 62 refs.

Dehalogenative and Deprotonative Lithiation of Pyridines: A Second Wind for Trimethylsilylmethylithium (TMSCH2Li)

Dehalogenative and Deprotonative Lithiation of Pyridines: A Second Wind for Trimethylsilylmethylithium (TMSCH2Li)

G.P.16.09. Phosphoglucomutase deficiency: A rare glycogen storage disease with an adult onset

Phosphoglumutase (PGM) is an enzyme of the glycolysis transforming the glucose-1-phosphate in glucose-6-phosphate. We report a patient presenting with muscle pain, cramps and stiffness beginning shortly after exercise. There was no second-wind phenomenon. He noticed twice that the urine was dark brown, indicating rhabdomyolysis. His neurological examination revealed at rest a moderate weakness of pelvic girdle muscles. CK level at rest were moderately elevated (300U/L) whereas after exercise CK levels were 10–20× normal.

Beliefs and attitudes regarding smoking cessation among American Indians: a pilot study.

American Indians (AI) have some of the highest smoking rates in the United States. The Muscogee Nation of Oklahoma developed a culturally targeted program called "Second Wind" based on the American Cancer Society's FreshStart smoking cessation program, but it has not been formally tested. We conducted six focus groups of AI adult smokers at the Haskell Health Center (Lawrence, Kansas). Focus groups assessed beliefs, attitudes, and behaviors related to smoking cessation, as well as participants' perceptions of the "Second Wind" curriculum's appropriateness and feasibility for this diverse group. Focus groups were audiotaped, transcribed, coded, and analyzed for content themes. Participants were 41 AI adults (63% female), 21-67 years of age. Participants smoked an average of 13 cigarettes per day, half had made a quit attempt in the past year, and 63% were daily smokers. For pharmacotherapy, most preferred the nicotine patch. Focus group responses were categorized into three major themes: traditional tobacco use, quitting and quit attempts, and the "Second Wind" program. Those who reported that traditional tobacco use is important were less inclined to use tobacco recreationally. Second Wind modifications suggested by participants included increasing use of AI imagery and addressing the meaning of tobacco to AI cultures. American Indian smokers are unique because of their traditional use of tobacco. Our participants felt that smoking cessation can be accomplished without discouraging traditional use of tobacco. We suggest ways to improve the "Second Wind" curriculum so that it is targeted for a heterogeneous group of AI smokers.

Effect of Fuels on Exercise Capacity in Muscle Phosphoglycerate Mutase Deficiency

Muscle phosphoglycerate mutase deficiency (PGAMD) is a rare, recessively inherited metabolic myopathy that affects one of the last steps of glycolysis. Clinically, PGAMD resembles muscle phosphorylase deficiency (McArdle disease) and phosphofructokinase deficiency (PFKD). However, it is unknown whether PGAMD is associated with a second-wind phenomenon during exercise, as in McArdle disease, and whether patients with PGAMD, like patients with PFKD and McArdle disease, benefit from supplementation with fuels that bypass the metabolic block. To investigate whether fuels that bypass the metabolic block can improve exercise capacity or whether exercise capacity improves during sustained exercise. Single-blind, placebo-controlled investigation of the effects of glucose, lactate, and intralipid on work capacity in patients with PGAMD. National University Hospital, University of Copenhagen, and Neuromuscular Center, Institute for Exercise and Environmental Medicine. Patients Two unrelated men (21 and 26 years old) with PGAMD who since their teens had experienced muscle cramps, muscle pain, and episodes of myoglobinuria provoked by brief vigorous exercise, 4 patients with McArdle disease (mean +/- SD age, 32 +/- 5 years) with 0% residual phosphorylase activity in muscle, and 6 healthy, untrained male volunteers (mean +/- SD age, 23 +/- 1 years) were studied. Using constant and variable workload protocols on a cycle ergometer, it was investigated whether a spontaneous second wind occurs during exercise in patients with PGAMD, and using a constant workload protocol followed by an incremental load to exhaustion, it was tested whether infusion of lactate, glucose, or intralipid alters the exercise tolerance in PGAMD. Whether a second wind occurs during exercise and whether fuels that bypass the metabolic block can improve exercise and oxidative capacity. In contrast to patients with McArdle disease, with whom they share many clinical features, in patients with PGAMD, cycle exercise and oxidative capacity are virtually normal, a second wind does not occur, and lipid and lactate supplements do not improve exercise capacity. Although the clinical manifestations of PGAMD mimic McArdle disease with respect to the presence of exertional muscle cramps, rhabdomyolysis, and myoglobinuria, this study shows that cycle exercise responses are strikingly different.

Will the U.S. economy get a second wind any time soon?

Will the U.S. economy get a second wind any time soon?

The windmill gets a second wind

The windmill gets a second wind

Second Wind for Second-Messenger Research

Second Wind for Second-Messenger Research

The Second Second Wind

The Second Second Wind

Janata gets a Second Wind

Janata gets a Second Wind

Second Wind - Trying to Catch It in the Lab.

(1975). Second Wind — Trying to Catch It in the Lab. The Physician and Sportsmedicine: Vol. 3, No. 5, pp. 74-76.

What Causes Second Wind?

(1974). What Causes Second Wind? The Physician and Sportsmedicine: Vol. 2, No. 11, pp. 37-42.