Strength training improves 5‐min all‐out performance following 185 min of cycling

To investigate the effects of heavy strength training on the mean power output in a 5‐min all‐out trial following 185 min of submaximal cycling at 44% of maximal aerobic power output in well‐trained cyclists. Twenty well‐trained cyclists were assigned to either usual endurance training combined with heavy strength training [E+S; n=11 (♂=11)] or to usual endurance training only [E; n=9 (♂=7, ♀=2)]. The strength training performed by E+S consisted of four lower body exercises [3 × 4–10 repetition maximum (RM)], which were performed twice a week for 12 weeks. E+S increased 1 RM in half‐squat (P≤0.001), while no change occurred in E. E+S led to greater reductions than E in oxygen consumption, heart rate, blood lactate concentration, and rate of perceived exertion (P<0.05) during the last hour of the prolonged cycling. Further, E+S increased the mean power output during the 5‐min all‐out trial (from 371 ± 9 to 400 ± 13 W, P<0.05), while no change occurred in E. In conclusion, adding strength training to usual endurance training improves leg strength and 5‐min all‐out performance following 185 min of cycling in well‐trained cyclists.     

Strength training improves performance and pedaling characteristics in elite cyclists

The purpose was to investigate the effect of 25 weeks heavy strength training in young elite cyclists. Nine cyclists performed endurance training and heavy strength training (ES) while seven cyclists performed endurance training only (E). ES, but not E, resulted in increases in isometric half squat performance, lean lower body mass, peak power output during Wingate test, peak aerobic power output (W_max), power output at 4 mmol L^?1 [la^?], mean power output during 40‐min all‐out trial, and earlier occurrence of peak torque during the pedal stroke (P < 0.05). ES achieved superior improvements in W_max and mean power output during 40‐min all‐out trial compared with E (P < 0.05). The improvement in 40‐min all‐out performance was associated with the change toward achieving peak torque earlier in the pedal stroke (r = 0.66, P < 0.01). Neither of the groups displayed alterations in VO_2max or cycling economy. In conclusion, heavy strength training leads to improved cycling performance in elite cyclists as evidenced by a superior effect size of ES training vs E training on relative improvements in power output at 4 mmol L^?1 [la^?], peak power output during 30‐s Wingate test, W_max, and mean power output during 40‐min all‐out trial.     

Strength training improves cycling performance,fractional utilization of VO2max and cycling economy in female cyclists

The purpose of this study was to investigate the effect of adding heavy strength training to well‐trained female cyclists’ normal endurance training on cycling performance. Nineteen female cyclists were randomly assigned to 11 weeks of either normal endurance training combined with heavy strength training (E+S, n = 11) or to normal endurance training only (E, n = 8). E+S increased one repetition maximum in one‐legged leg press and quadriceps muscle cross‐sectional area (CSA) more than E (P < 0.05), and improved mean power output in a 40‐min all‐out trial, fractional utilization of VO_2max and cycling economy (P < 0.05). The proportion of type IIAX‐IIX muscle fibers in m. vastus lateralis was reduced in E+S with a concomitant increase in type IIA fibers (P < 0.05). No changes occurred in E. The individual changes in performance during the 40‐min all‐out trial was correlated with both change in IIAX‐IIX fiber proportion (r = ?0.63) and change in muscle CSA (r = 0.73). In conclusion, adding heavy strength training improved cycling performance, increased fractional utilization of VO_2max, and improved cycling economy. The main mechanisms behind these improvements seemed to be increased quadriceps muscle CSA and fiber type shifts from type IIAX‐IIX toward type IIA.     

A new model of short acceleration‐based training improves exercise performance in old mice

In order to identify a more appealing exercise strategy for the elderly, we studied a mouse model to determine whether a less time‐consuming training program would improve exercise performance, enzyme activities, mitochondrial respiration, and metabolomic parameters. We compared the effects of short‐session (acceleration‐based) training with those of long‐session endurance training in 23‐month‐old mice. The short‐session training consisted of five acceleration‐based treadmill running sessions over 2 weeks (the acceleration group), whereas the endurance training consisted of five‐one‐hour treadmill sessions per week for 4 weeks (the endurance group). A control group of mice was also studied. In the acceleration group, the post‐training maximum running speed and time to exhaustion were significantly improved, relative to pretraining values (+8% for speed, P<.05; +10% for time to exhaustion, P<.01). The post‐training maximum running speed was higher in the acceleration group than in the endurance group (by 23%; P<.001) and in the control group (by 15%; P<.05). In skeletal muscle samples, the enzymatic activities of citrate synthase, lactate dehydrogenase, and creatine kinase were significantly higher in the acceleration group than in the endurance group. Furthermore, mitochondrial respiratory activity in the gastrocnemius was higher in the acceleration group than in the control group. A metabolomic urine analysis revealed a higher mean taurine concentration and a lower mean branched amino acid concentration in the acceleration group. In old mice, acceleration‐based training appears to be an efficient way of increasing performance by improving both aerobic and anaerobic metabolism, and possibly by enhancing antioxidant defenses and maintaining muscle protein balance.     

Effects of 12 weeks of block periodization on performance and performance indices in well‐trained cyclists

The purpose of this study was to compare the effects of two different methods of organizing endurance training in trained cyclists during a 12‐week preparation period. One group of cyclists performed block periodization (BP; n = 8), wherein every fourth week constituted five sessions of high‐intensity aerobic training (HIT), followed by 3 weeks of one HIT session. Another group performed a more traditional organization (TRAD; n = 7), with 12 weeks of two weekly HIT sessions. The HIT was interspersed with low‐intensity training (LIT) so that similar total volumes of both HIT and LIT were performed in the two groups. BP achieved a larger relative improvement in VO_2max than TRAD (8.8 ± 5.9% vs 3.7 ± 2.9%, respectively, P < 0.05) and a tendency toward larger increase in power output at 2 mmol/L [la^?] (22 ± 14% vs 10 ± 7%, respectively, P = 0.054). Mean effect size (ES) of the relative improvement in VO_2max, power output at 2 mmol/L [la^?], hemoglobin mass, and mean power output during 40‐min all‐out trial revealed moderate superior effects of BP compared with TRAD training (ES range was 0.62–1.12). The present study suggests that BP of endurance training has superior effects on several endurance and performance indices compared with TRAD.     

Effects of concurrent exercise training on muscle dysfunction and systemic oxidative stress in older people with COPD

Oxidative stress is associated with disease severity and limb muscle dysfunction in COPD. Our main goal was to assess the effects of exercise training on systemic oxidative stress and limb muscle dysfunction in older people with COPD. Twenty‐nine outpatients with COPD (66‐90 years) were randomly assigned to a 12‐week exercise training (ET; high‐intensity interval training (HIIT) plus power training) or a control (CT; usual care) group. We evaluated mid‐thigh muscle cross‐sectional area (CSA; computed tomography); vastus lateralis (VL) muscle thickness, pennation angle, and fascicle length (ultrasonography); peak VO₂ uptake (VO_2peak) and work rate (W_peak) (incremental cardiopulmonary exercise test); rate of force development (RFD); maximal muscle power (P_max; force‐velocity testing); systemic oxidative stress (plasma protein carbonylation); and physical performance and quality of life. ET subjects experienced changes in mid‐thigh muscle CSA (+4%), VL muscle thickness (+11%) and pennation angle (+19%), VO_2peak (+14%), W_peak (+37%), RFD (+32% to 65%), P_max (+38% to 51%), sit‐to‐stand time (?24%), and self‐reported health status (+20%) (all P < 0.05). No changes were noted in the CT group (P > 0.05). Protein carbonylation decreased among ET subjects (?27%; P < 0.05), but not in the CT group (P > 0.05). Changes in protein carbonylation were associated with changes in muscle size and pennation angle (r = ?0.44 to ?0.57), exercise capacity (r = ?0.46), muscle strength (r = ?0.45), and sit‐to‐stand performance (r = 0.60) (all P < 0.05). The combination of HIIT and power training improved systemic oxidative stress and limb muscle dysfunction in older people with COPD. Changes in oxidative stress were associated with exercise‐induced structural and functional adaptations.     

Mechanical and morphological determinants of peak power output in elite cyclists

Mechanical peak power output (PPO) is a determinant of performance in sprint cycling. The purpose of this study was to examine the relationship between PPO and putative physiological determinants of PPO in elite cyclists, and to compare sprint performance between elite sprint and endurance cyclists. Thirty-five elite cyclists (18 endurance; 17 sprint) performed duplicate sprint cycling laboratory tests to establish PPO and its mechanical components. Quadriceps femoris (Q_VOL) and hamstring muscle volume (HAM_VOL) were assessed with MRI, vastus lateralis pennation angle (Pθ_VL) and fascicle length (FL_VL) were determined with ultrasound imaging, and neuromuscular activation of three muscles was assessed using EMG at PPO during sprint cycling. For the whole cohort, there was a wide variability in PPO (range 775-2025 W) with very large, positive, bivariate relationships between PPO and Q_VOL (r = .87), HAM_VOL (r = .71), and Pθ_VL (r = .81). Step-wise multiple regression analysis revealed that 87% of the variability in PPO between cyclists was explained by two variables Q_VOL (76%) and Pθ_VL (11%). The sprint cyclists had greater PPO (+61%; P < .001 vs endurance), larger Q_VOL (P < .001), and BF_VOL (P < .001) as well as more pennate vastus lateralis muscles (P < .001). These findings emphasize the importance of quadriceps muscle morphology for sprint cycling events.     

Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO2max), cycling economy (CE) and long/short-term endurance capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P<0.01) but not E. VO2max remained unchanged. CE improved in E to reach values seen in SE. Short-term (5-min) endurance performance increased (3-4%) after SE and E (P<0.05), whereas 45-min endurance capacity increased (8%) with SE only (P<0.05). Type IIA fiber proportions increased and type IIX proportions decreased after SE training (P<0.05) with no change in E. Muscle fiber area and capillarization remained unchanged. In conclusion, concurrent strength/endurance training in young elite competitive cyclists led to an improved 45-min time-trial endurance capacity that was accompanied by an increased proportion of type IIA muscle fibers and gains in MVC and RFD, while capillarization remained unaffected.     

Effect of exercise intervention on thigh muscle volume and anatomical cross‐sectional areas—Quantitative assessment using MRI

The objective of this study was to evaluate the location‐specific magnitudes of an exercise intervention on thigh muscle volume and anatomical cross‐sectional area, using MRI. Forty one untrained women participated in strength, endurance, or autogenic training for 12 weeks. Axial MR images of the thigh were acquired before and after the intervention, using a T1‐weighted turbo‐spin‐echo sequence (10 mm sections, 0.78 mm in‐plane resolution). The extensor, flexor, adductor, and sartorius muscles were segmented between the femoral neck and the rectus femoris tendon. Muscle volumes were determined, and anatomical cross‐sectional areas were derived from 3D reconstructions at 10% (proximal‐to‐distal) intervals. With strength training, the volume of the extensors (+3.1%), flexors (+3.5%), and adductors (+3.9%) increased significantly (P < 0.05) between baseline and follow‐up, and with endurance training, the volume of the extensor (+3.7%) and sartorius (+5.1%) increased significantly (P < 0.05). No relevant or statistically significant change was observed with autogenic training. The greatest standardized response means were observed for the anatomical cross‐sectional area in the proximal aspect (10–30%) of the thigh and generally exceeded those for muscle volumes. The study shows that MRI can be used to monitor location‐specific effects of exercise intervention on muscle cross‐sectional areas, with the proximal aspect of the thigh muscles being most responsive. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.     

Prolonged constant load cycling exercise is associated with reduced gross efficiency and increased muscle oxygen uptake

This study investigated the effects of prolonged constant load cycling exercise on cycling efficiency and local muscle oxygen uptake responses. Fourteen well‐trained cyclists each completed a 2‐h steady‐state cycling bout at 60% of their maximal minute power output to assess changes in gross cycling efficiency (GE) and muscle oxygen uptake (mVO₂) at time points 5, 30, 60, 90, and 120 min. Near‐infrared spatially resolved spectroscopy (NIRS) was used to continually monitor tissue oxygenation of the Vastus Lateralis muscle, with arterial occlusions (OCC) applied to assess mVO₂. The half‐recovery time of oxygenated hemoglobin (HbO₂) was also assessed pre and post the 2‐h cycling exercise by measuring the hyperemic response following a 5‐min OCC. GE significantly declined during the 2‐h cycling bout (18.4 ± 1.6 to 17.4 ± 1.4%; P < 0.01). Conversely, mVO₂ increased, being significantly higher after 90 and 120 min than at min 5 (+0.04 mlO₂/min/100 g; P = 0.03). The half‐recovery time for HbO₂ was increased comparing pre and post the 2‐h cycling exercise (+7.1 ± 19s), albeit not significantly (d: 0.48; P = 0.27). This study demonstrates that GE decreases during prolonged constant load cycling exercise and provides evidence of an increased mVO₂, suggestive of progressive mitochondrial or contractile inefficiency.     

Changes in peak fat oxidation in response to different doses of endurance training

The effect of different doses of endurance training on the capacity to oxidize fat during exercise in sedentary, overweight men and assessment of variables associated with changes in peak fat oxidation (PFO) were evaluated. Young, sedentary, overweight men were randomized to either the high‐dose (HIGH, 600 kcal/day, n = 17) or moderate‐dose (MOD, 300 kcal/day, n = 18) endurance training groups or controls (CON, n = 15). PFO and peak oxygen uptake (VO₂ peak) were measured using indirect calorimetry, body composition using dual‐energy x‐ray absorptiometry, and protein levels of mitochondrial enzymes determined by Western blotting. PFO increased in both MOD [1.2 mg/kg fat‐free mass (FFM)/min, 95% confidence interval (CI): 0.08:2.3, P = 0.03] and HIGH (1.8 mg/kg FFM/min, CI: 0.6:2.9, P < 0.001) compared with CON. Skeletal muscle expression of citrate synthase, β‐hydroxyacyl‐CoA dehydrogenase, and mitochondrial oxphos complexes II‐V increased similarly in MOD and HIGH. Stepwise multiple linear regression analysis with backward elimination of individual variables correlated with changes in PFO revealed increases in cycling efficiency, FFM, and VO₂ peak as the remaining associated variables. In conclusion, PFO during exercise increased with both moderate‐ and high‐dose endurance training. Increases in PFO were mainly predicted by changes in VO₂ peak, FFM, and cycling efficiency, and less with skeletal muscle mitochondrial enzymes.     

Effect of short‐term heat acclimation with permissive dehydration on thermoregulation and temperate exercise performance

We examined the effect of short‐term heat acclimation with permissive dehydration (STHADe) on heat acclimation (HA) and cycling performance in a temperate environment. Ten trained male cyclists [mean (SD) maximal oxygen uptake: 63.3(4.0) mL/kg/min; peak power output (PPO): 385(40) W; training: 10 (3) h/week] underwent a STHADe program consisting of 5 days of exercise (maximum 90 min/day) in a hot environment (40 °C, 50% RH) to elicit isothermic heat strain [rectal temperature 38.64(0.27) °C]. Participants abstained from fluids during, and 30 min after, HA sessions. Pre‐ and post‐STHADe HA was evaluated during euhydrated fixed‐intensity exercise (60 min) in hot conditions; the effect of STHADe on thermoregulation was also examined under temperate conditions (20 min fixed‐intensity exercise; 22 °C, 60% RH). Temperate cycling performance was assessed by a graded exercise test (GXT) and 20‐km time trial (TT). STHADe reduced thermal and cardiovascular strain in hot and temperate environments. Lactate threshold [Δ = 16 (17) W] and GXT PPO [Δ = 6 (7) W] were improved following STHADe (P < 0.05), but TT performance was not affected (P > 0.05), although there was a trend for a higher mean power (P = 0.06). In conclusion, STHADE can reduce thermal and cardiovascular strain under hot and temperate conditions and there is some evidence of ergogenic potential for temperate exercise, but longer HA regimens may be necessary for this to meaningfully influence performance.     

Inspiratory flow resistive loading improves respiratory muscle function and endurance capacity in recreational runners

The purpose of this study was to assess the efficacy of inspiratory flow resistive loading (IFRL) on respiratory muscle function, exercise performance and cardiopulmonary and metabolic responses to exercise. Twenty‐four recreational road runners (12 male) were randomly assigned from each gender into an IFRL group (n=8) and sham‐IFRL group (n=8), which performed IFRL for 6 weeks, or a control group (n=8). Strength (+43.9%Δ), endurance (+26.6%Δ), maximum power output (+41.9%Δ) and work capacity (+38.5%Δ) of the inspiratory muscles were significantly increased (P<0.05) at rest following the study period in IFRL group only. In addition, ventilation (?25.7%Δ), oxygen consumption (?13.3%Δ), breathing frequency (?11.9%Δ), tidal volume (?16.0%Δ), heart rate (HR) (?13.1%Δ), blood lactate concentration (?38.9%Δ) and the perceptual response (?33.5%Δ) to constant workload exercise were significantly attenuated (P<0.05), concomitant with a significant improvement (P<0.05) in endurance exercise capacity (+16.4%Δ) during a treadmill run set at 80% in IFRL group only. These data suggest that IFRL can alter breathing mechanics, attenuate the oxygen cost, ventilation, HR, blood lactate and the perceptual response during constant workload exercise and improve endurance exercise performance in recreational runners.     

Effects of resistance training with whole‐body vibration on muscle fitness in untrained adults

The effects of resistance training (RT) combined with whole‐body vibration (WBV) on muscle fitness, particularly muscle hypertrophy and neuromuscular performance, are not well understood. We investigated the effects of WBV in healthy, untrained participants after a 13‐week RT course by performing magnetic resonance imaging and by measuring maximal isometric (with electromyography) and isokinetic knee extension strengths, isometric lumbar extension torque, countermovement‐jump, knee extension endurance, and sit‐ups. Thirty‐two individuals (22–49 years old) were randomly assigned to RT groups with (RT‐WBV, n=16) or without WBV (RT, n=16). Following the RT course, significantly higher increases in the cross‐sectional areas of m. psoas major (vs baseline values) and erector spinae muscle (vs the RT group) were observed in the RT‐WBV group (+10.7%, P<0.05; +8.7%, P<0.05) compared with the RT group (+3.8%, P=0.045; 0.0%). Higher increases from baseline were also observed in maximal isometric force, concentric knee extension torque, countermovement‐jump, and maximal isometric lumbar extension torque in RT‐WBV (+63.5%; +76.7%, +15.0%, and +51.5%, respectively; P<0.05) than in those of RT (+25.6%, P=0.001; +17.8%, P=0.18; +11.3%, P=0.001; and +26.4%, P<0.001, respectively). The WBV‐induced increases in muscle hypertrophy and isometric lumbar extension torque suggest a potential benefit of incorporating WBV into slow‐velocity RT programs involving exercises of long duration.     

Specific muscle adaptations in type II fibers after high‐intensity interval training of well‐trained runners

High‐intensity interval training (HIIT) forms an important component of endurance athletes' training, but little is known on intramuscular metabolic and fiber type adaptations. This study investigated physiological and skeletal muscle adaptations in endurance runners subjected to 6 weeks HIIT. Eighteen well‐trained endurance athletes were subjected to 6 weeks HIIT. Maximal and submaximal exercise tests and muscle biopsies were performed before and after training. Results indicated that peak treadmill speed (PTS) increased (21.0 ± 0.8 vs 22.1 ± 1.2 km/h, P<0.001) and plasma lactate decreased at 64% and 80% PTS (P<0.05) after HIIT. Cross‐sectional area of type II fibers tended to have decreased (P=0.06). No changes were observed in maximal oxygen consumption, muscle fiber type, capillary supply, citrate synthase and 3‐hydroxyacetyl CoA dehydrogenase activities. Lactate dehydrogenase (LDH) activity increased in homogenate (P<0.05) and type IIa fiber pools (9.3%, P<0.05). The change in the latter correlated with an absolute interval training speed (r=0.65; P<0.05). In conclusion, HIIT in trained endurance runners causes no adaptations in muscle oxidative capacity but increased LDH activity, especially in type IIa fibers and in relation to absolute HIIT speed.     

Effects of high‐intensity interval cycling performed after resistance training on muscle strength and hypertrophy

Aim of the study was to investigate whether high‐intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty‐two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high‐intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross‐sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P < 0.05) and REC (type I: 10.0 ± 2.7%, type IIA: 14.8 ± 4.3% type IIX: 20.8 ± 6.0%, P < 0.05). In contrast, RFD decreased and fascicle angle increased (P < 0.05) only after REC. Capillary density and estimated aerobic capacity increased (P < 0.05) only after REC. These results suggest that high‐intensity interval cycling performed after heavy‐resistance exercise may not inhibit resistance exercise‐induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high‐intensity cycling after heavy‐resistance exercise may decrease RFD partly due to muscle architectural changes.     

Progenitor cell mobilization after exercise is related to systemic levels of G‐CSF and muscle damage

Different types of exercise are characterized by the ability to induce specific physiological stimuli that might be able to induce the mobilization of progenitor cells. The aim of the current study was to investigate the mobilization of hematopoietic progenitor cells (HPCs) and endothelial progenitor cells (EPCs) in response to endurance, resistance, and eccentric endurance exercise and their relation to markers of muscle damage and inflammation. Healthy male subjects performed acute bouts of either endurance exercise, resistance exercise, or eccentric endurance exercise. Numbers of progenitor cells and several markers of muscle damage and inflammation were determined. Although the endurance exercise was followed by an immediate and short increase of both HPCs and EPCs, the eccentric exercise evoked a long lasting increase up to 24 h for HPCs and 48 h for EPCs (P < 0.05). After resistance exercise, an increase of HPCs was only found 3 h after exercise (P < 0.05). A correlation was found between mobilized progenitor cells and systemic levels of granulocyte colony‐stimulating factor (G‐CSF) levels (r = 0.54 and r = 0.51, P < 0.05) as well as for HPCs and creatine kinase levels (r = 0.57, P < 0.05). These results suggest that mobilization of progenitor cells is related to the type of exercise and possibly mediated by G‐CSF and muscle damage.     

Combined effects of whole-body vibration, resistance exercise, and vascular occlusion on skeletal muscle and performance

The purpose of this study was to evaluate the effects of a new high-intensity training modality comprised of vibration exercise with superimposed resistance exercise and vascular occlusion (vibroX) on skeletal muscle and performance. Young untrained women were randomized to either train in a progressive mode on 3 days per week for 5 weeks ( N=12) or to maintain a sedentary lifestyle ( N=9). VibroX increased peak cycling power (+9%, P=0.001), endurance capacity (+57%, P=0.002), ventilatory threshold (+12%, P<0.001), and end-test torque (+15%, P=0.002) relative to the sedentary group. Training load increased by 84.5% ( P<0.001) after vibroX. The increases were paralleled by increases in myosin heavy chain type 1 vastus lateralis muscle fiber cross-sectional area (+14%, P=0.031) and proportion (+17%, P=0.015), thigh lean mass (+4%, P=0.001), capillary-to-fiber ratio (+14%, P=0.003), and cytochrome c oxidase activity. Conversely, maximal values for oxygen consumption, cardiac output, isokinetic leg extension power and jumping power remained unaffected. Notably, vastus lateralis muscle adaptations were achieved with a very low weekly training volume. We conclude that vibroX quickly increases muscle (fiber) size, capillarization, and oxidative potential, and markedly augments endurance capacity in young women.     

Placebo in sports nutrition: a proof‐of‐principle study involving caffeine supplementation

We investigated the effects of supplement identification on exercise performance with caffeine supplementation. Forty‐two trained cyclists (age 37 ± 8 years, body mass [BM] 74.3 ± 8.4 kg, height 1.76 ± 0.06 m, maximum oxygen uptake 50.0 ± 6.8 mL/kg/min) performed a ~30 min cycling time‐trial 1 h following either 6 mg/kgBM caffeine (CAF) or placebo (PLA) supplementation and one control (CON) session without supplementation. Participants identified which supplement they believed they had ingested (“caffeine”, “placebo”, “don't know”) pre‐ and post‐exercise. Subsequently, participants were allocated to subgroups for analysis according to their identifications. Overall and subgroup analyses were performed using mixed‐model and magnitude‐based inference analyses. Caffeine improved performance vs PLA and CON (P ≤ 0.001). Correct pre‐ and post‐exercise identification of caffeine in CAF improved exercise performance (+4.8 and +6.5%) vs CON, with slightly greater relative increases than the overall effect of caffeine (+4.1%). Performance was not different between PLA and CON within subgroups (all P > 0.05), although there was a tendency toward improved performance when participants believed they had ingested caffeine post‐exercise (P = 0.06; 87% likely beneficial). Participants who correctly identified placebo in PLA showed possible harmful effects on performance compared to CON. Supplement identification appeared to influence exercise outcome and may be a source of bias in sports nutrition.