6 Gender Differences in Strength The notion of dichotomous populations results from:Differences in the endocrine systemCultural and participation factors“Based on opportunities to become engaged and the encouragement to pursue” . . .
7 Strength DifferencesFemales possess 40-60% of upper-body strength and 70-75% of lower body strength of men (7).It should not be viewed in absolute terms because it is NOT consistent for all muscle groups
8 Strength Differences Corrected for muscle mass, strength was no different and . . .Based on strength to lean body mass ratio, women are about equal in strength to men – when strength is calculated per X-sectional area of muscle
9 Conclusions & Implications Well-trained females often resemble athletic males MORE CLOSELY than their female peers!And muscle tissue has the same force development capability independent of gender.
10 Fiber Type Distribution Is also similar between genders, but males may have a greater % of FT fibers and a larger Type II to Type I fiber ratio.However, it has been shown that women may be able to use a greater proportion of stored elastic energy during activities in which the muscle is pre-stretched (SSC vertical jump) (7).
11 Long Term Strength Adaptation Is the same . . while, gradually increasing muscular hypertrophy contributes to strength development primarily during the later weeks and months of training (9), the nervous system contributes to further strength development.
12 Long Term Strength Adaptation Px ~ When female athletes are exposed to two training sessions of high intensity and short duration per day versus one session of longer duration per day, they improve their max strength and max voluntary neural activation of the trained muscles (9).
13 Muscle Fatigue and Functional Power Loss New research suggests well-trained females actually lose less strength than males during the course of a rigorous work-out and recover their muscular prowess more rapidly after an exhausting bout of exercise (3).
15 R.T. will cause females to become larger and heavier Education Services Human Motion Inc.R.T. will cause females to become larger and heavierTruth!Women with :a genetic predisposition to hypertrophywho participate in high volume, high intensity training will see substantial increases in limb circumference.Copyright 2009Contact Carmen at
16 Women should use different R.T. training methods than men Myth! No evidence that women are more likely to be injured from RT than menAll participants should follow the same principles of training (overload, specificity, individualization & variation) regardless of gender – rate of progression is individual not gender dependant.
17 Women should avoid high intensity and high load training Myth! In fact, training loads that are substantially below those necessary for physiologic adaptations absolutely will not help women achieve strength and/or muscularity goalsThis seems to be less of a problem with men ~ why?
18 Hormone InfluencesWomen with higher FTES levels have greater potential for muscle strength and hypertrophyGH can be influenced by training protocols that elicit high levels of blood lactate (eg 4x10 reps, 1 min off, large muscle groups)= muscle development over time
19 Section B: Cardiovascular Response and Adaptation to Training
20 Characteristics of Blood Adults have 5 litres of bloodConsists of plasma and blood cellsPlasma is clear and yellowishRed blood cells make up 40-45% of total quantity of blood – this is called the hemotocrit
22 Hematocrit (Hct) The % of red blood cells Normal Hct Males 40-54% or 41-55%Females 37-50% or 36-48% (24)Red colour of blood is caused by a ferrous (iron-rich) protein called Hemoglobin (Hb)
23 Males versus Females Hb binds to O2. Men have avg 15.6 g/dL per 100 ml of blood, women have 13.8 g/dL grams due to menstruation losses, lower blood levels of androgenic steroids and diet.Therefore women’s O2 transport is lower because of the lower levels of Hb
24 Performance Implications of Low Hb EG: If Hb decreases from 10 to 9 millimoles per litre, the blood will be capable of transporting 10% less oxygen.VO2 max then decreases by 10%Body switches to anaerobic system and lactate is formed earlier
25 Also . . . When Hb decreases HR increases Because the heart must circulate more blood to maintain the same level of O2 transport (24)
26 Heart Rate and Stroke Volume HR max is generally the same in both gendersBut… Women have a lower stroke volume which is a result of:1. Smaller heart, small ventricles and lower testosterone2. Smaller blood volume
27 Cardiovascular Adaptation CV response is generally the same for men and womenDependant on the intensity and duration of the exerciseAdaptation is due to changes, both centrally and peripherally, which facilitate oxygen delivery to the working muscles
28 Capacity for Aerobic Power: Men vs. Women (before menopause) Before puberty there are no differences (11).After…there are 3 basic physiological differences between men and women that affect the capacity for aerobic power
29 These differences are because Females have:1. a higher % of body fat2. A smaller O2 carrying capacity3. A smaller muscle fiber area
30 DifferencesBody fat and weight are corrected mathematically (per kg of lean tissue), the differences are lessened to approx 5%The remaining % is either still a difference in conditioning or more likely a sex related difference in the ability to transport and utilize oxygen.
31 Less Muscle MassIn endurance trained women, they have 85% of the muscle fiber area of endurance trained men (11)…
33 Fat Metabolism Fat is stored in the form of triglycerides (TG) TG are made up of FFA molecules held together by a molecule of glycerolBody fat is stored in fat cells called adipocytes50,000–60,000 kcal are stored in fat cells
34 Fat Metabolism 2,000-3,000 kcal are stored in muscle (IMTG) and blood. During exercise TG (FFA) in fat cells, muscle and blood can be broken down (lipolysis) and used as fuel by the exercising muscles.
35 Storage Women have higher % fat than men 20-25% is healthy for non-athlete women and 10-15% is healthy for men. (13)10-13% is essential for female athletesMobilization refers to the process of releasing fat from storage sites in the body.
36 Enzymes 2 main enzymes that regulate mobilization of FFA: hormone sensitive lipase (HSL)lipoprotein lipase (LPL)Epinephrine stimulates lipolysis; it binds to receptors and activate HSL
37 EnzymesHSL responsiveness to epinephrine is enhanced due to an increase in body temperature and a greater concentration of epinephrine blood vs at restAn endurance-trained individual, HSL responsiveness is enhanced, HSL can be activated by a lower concentration of Epinephrine
38 EnzymesTherefore a metabolic training effect of aerobic exercise is: enhanced receptiveness to mobilize and break apart TG for energy.*Obesity (>35% bf) blunts this responsiveness
39 EnzymesLPL is the gatekeeper that controls the distribution of fat in the various storage depots of the bodyResearch has shown that abdominal adipocytes are more sensitive to receptor stimulation and are therefore easier to mobilize than fat located in the hip & thigh area.
40 StorageBecause there are more “alpha receptors” in females around the hip and thigh region, this would favor the storage of fat as opposed to the mobilization of fat in this area.Women also have a greater LPL concentration & activity in the hip and thigh region
41 Estrogen and Lipolysis Estrogen may aid in the mobilization of fat from adipose tissueInhibits the hormone LPLEstrogen has been shown to enhance epinephrine productionBeen reported to stimulate the production of growth hormone
42 Growth HormoneGrowth hormone inhibits the uptake of glucose by active tissues and increases the mobilization of FFA from adipose tissueGH inhibits insulin production from the pancreas and stimulating HSLThis would decrease glucose metabolism & increase FFA utilization during exercise
43 IntensityAs exercise intensity increases, so does total energy expenditureEven though % from fat is less, TOTAL fat calories are GREATER because there is a greater absolute energy expenditure (13)
44 General Px for Optimizing Fat Metabolism LSD will mobilize fat but this method takes way too long!High intensity training burns more caloriesCross train to avoid overuse injuries = ability to do more workLT approach ~ Improve structural integrity to do more work over time
45 Specific PxModerately heavy, low repetition training - increases a woman’s metabolic rate more than light weight, high repetition trainingBodybuilder routines have too much volume and hypertrophy may occur – the tension stimulus is of long duration and the rest periods are too short (60 sec) = hypertrophy
46 Specific PxSuperset OPPOSING exercises (exercises that do not contribute to fatigue of the other)Use bodyweight exercises (forces women to work harder)* compare a push-up to a chest pressPrescribe intervals ONLY – no LSD CARDIO! Yes, I repeat NO CARDIO! Go for the ‘afterburn’
47 Specific Px Keep the program consistent for exactly 4 weeks Replace volume (multiple sets) with more total body exercises*remember: total volume per muscle group equals hypertrophy!
48 Education Services Human Motion Inc. Specific PxNo crunches, no curls - Remove all isolation exercises, even ‘prehab’ workSelect 4 multi-joint free weight exercises: A squat, a push or press, a pull and a lungeCycle through in a circuit versus a horizonal PxCopyright 2009Contact Carmen at
49 Specific Px3 sessions per week, All ‘F.W.T.B.E.’ (no body-part training workouts)Expect 90% commitment (anything less will not get results)Download free fat loss workouts at
55 Gender Strength and Reactivity Differences 20-30% of female athletes have one leg significantly weaker than the other legIf diff is 15%, they are 2.6 times more likely to suffer injuryTypically demonstrate a slower speed of muscle contraction (RFD); average takes 3 tenths of a sec longer to generate maximum contraction of the hamstrings
56 Gender differences con’t Females demonstrate different muscle activation patterns compared to males, they are typically quad dominant (places stress on ACL**) ~ postures in high heeled shoesFemales demonstrate a lower hamstring to quadricep ratio
57 Importance of Hamstrings Hamstrings activity can reduce ACL loading.At >20 degrees of knee flexion, hamstrings co-contraction is effective at countering the anterior drawer of the quads (More, 1993, 21)Also increases support against external valgus, varus and IR/ER forces
58 Knee Ligaments: ACL and PCL They cross each other and are the primary stabilizers of the kneeThey maintain rotary stability of the knee and prevent the lower leg (tibia) from moving either too far forward or backward on the upper portion (Femur) of the leg at the knee.
60 ACL and Hamstrings function When the foot is on contact with the ground, the ACL stops the femur from sliding forward on the tibia.With the foot planted on the ground, the hamstrings ALSO contract to prevent the femur from sliding forward on the tibia.
61 ACL Injury - Statistics Females have 2-6 times the risk of ACL injuries as males (Moeller, 1997, 21)Over 1.4 million women in the USA have suffered an ACL injury in the last 10 yrsAn estimated 38,000 per year (2004)Ankle sprains have decreased by 86%and knee ligament injuries have increased by 172% (Lobo, 2000, 21).
62 Statistics 70% are non-contact injuries (Ramus, 2002) Age range : 15-25Untrained females have a 3.6 times higher incidence of knee injury and 4.8 times more likely than males
63 ACL Tear Mechanisms From planting and cutting 29% The loading on the ACL during quick change of direction maneuvers is 2 times higher than during normal running
64 ACL Tear Mechanisms Straight knee landing 28% Landing with hyper-extended knee 26%** Women landing from a jump generate higher peak impact forces than men over a shorter period of time and also generally have less neuromuscular control** 7 times more likely to tear in games vs practices!!!
65 Prevention: Neuromuscular Learning Study by Beiser (2000) on cutting maneuvers that muscles can reduce the varus/valgus moments applied to the ligaments by up to 90%, which is largely the result of generalized ham/quad co-contraction
66 Neuromuscular Modulations from Stability Training RT on machines does NOT require stabilization in the varus/valgus and IR/ER directions at the kneeAthlete learns to maximize activation patterns to generate flexion and extension ONLYThis leads to a decrease in co-contraction
67 Strength and PowerPlyometric training programs have been shown to enhance muscle voluntary reaction times and peak time to force torque (Hakkinen, 1986; Sale, 1988; Wojtys, 1996)Heavy RT increase strength but not reaction times
68 Stability and BalanceImprovement in hamstrings voluntary reaction time and time to peak torque also improved in subjects who have undergone stability and balance training (Ihara, 1986)
69 Exercise Prescription Women cannot rely on ligamentous structures to prevent injuryBalance training: stationary and dynamicJump training: techniques, linear, vertical, lateral, two-one leg *get off the BOSU*Strengthening: power, specific for hamstrings, dynamic balance
70 As a personal trainerID female clients that are more susceptible to knee injuriesUnderstand the biomechanics that can lead to increase joint stressKnow the effect of muscle and limb imbalancesKnow how to design a program that addresses these issues
72 ReferencesLow-Volume circuit versus high volume periodized resistance training in women. Marx et al. Med Sci in Sports and Exercise (33)Strength training the female athleteThe “rap” sheet on female athletes says they don’t recover from hard training as well as males do – neuromuscular fatigue and Recovery in male and female athletes during heavy resistance exercise. Int J of Sports Med (14)Age-related differences in metabolic adaptations following resistance training in women. Melancon et alSex Differences in maximal oxygen uptake. European J of Applied Physiology (54)Influence of RT volume and periodization on physiological and performance adaptations in college women tennis players. Kraemer et al Am J of Sports Med. (28).
73 ReferencesStrength training for women: debunking the myths that block opportunity. Ebben et al. The Physician and Sports Med (26).Muscle hypertrophy and fast twitch fiber type conversions in heavy resistance trained women. European j of Appl Phy (60).Distribution of strength training volume into one or two daily sessions and neuromuscular adaptations in female athletes. Electromyo & Clinical Neurophys (34).Muscle Hypertrophy and fast fiber type conversions in heavy resistance-trained women. Staron et al. Eur J of Appl Phys (60).
74 References Cardiovascular Responses to Exercise. O’Toole. Gender Differences in fat Metabolism. Vella and Kravitz,How endurance training helps women keep their weight down Am J of Phys 279, E601Supercompensation works for women – but better for men J Appl Physiol 88.Ironman triathletes; gender differences. Int J of Sports Nutrition and Exercise Metabolism, 2002 (12)Effects of Menstrual Cycle on Exercise performance. Review. Sports Med 2003 (33)Menstrual Dysfunction – the energy drain for female athletes. Sports Med 2002 (32).Growth Hormones Responses to an acute bout of resistance exercise in weight trained and non-weight trained women. Journal of S&C research 2000 (14)Unborn babies cope well with intensive workouts. Ostet Gynaecol 2000 (96).Evaluation and Training of the Female Athlete to prevent serious knee injuries. NSCA Conference. Tyson & Cook
75 ReferencesKnee Joint Laxity and Neuromuscular Characteristics of male and female soccer and basketball players. AJSM (27) abstractA comparison of Knee Kinetics between male and female recreational athletes in stop-jump tasks AJSM (30)Jump landing strategies in male and female college athletes and implications for ACL injury AJSM (31)The effect of neuromuscular training on the incidence of knee injury in female athletes AJSM (27)Secrets of Female Strength and Conditioning. grrlAthlete.com, 2004.Lactate Threshold Training. Peter JanssenExercise Physiology, 2nd Edition. Brooks, Fahey & White